Move most of the peculiar argument handling for external calls into the parser (#13089)

# Description

We've had a lot of different issues and PRs related to arg handling with
externals since the rewrite of `run-external` in #12921:

- #12950
- #12955
- #13000
- #13001
- #13021
- #13027
- #13028
- #13073

Many of these are caused by the argument handling of external calls and
`run-external` being very special and involving the parser handing
quoted strings over to `run-external` so that it knows whether to expand
tildes and globs and so on. This is really unusual and also makes it
harder to use `run-external`, and also harder to understand it (and
probably is part of the reason why it was rewritten in the first place).

This PR moves a lot more of that work over to the parser, so that by the
time `run-external` gets it, it's dealing with much more normal Nushell
values. In particular:

- Unquoted strings are handled as globs with no expand
- The unescaped-but-quoted handling of strings was removed, and the
parser constructs normal looking strings instead, removing internal
quotes so that `run-external` doesn't have to do it
- Bare word interpolation is now supported and expansion is done in this
case
- Expressions typed as `Glob` containing `Expr::StringInterpolation` now
produce `Value::Glob` instead, with the quoted status from the expr
passed through so we know if it was a bare word
- Bare word interpolation for values typed as `glob` now possible, but
not implemented
- Because expansion is now triggered by `Value::Glob(_, false)` instead
of looking at the expr, externals now support glob types

# User-Facing Changes

- Bare word interpolation works for external command options, and
otherwise embedded in other strings:
  ```nushell
  ^echo --foo=(2 + 2) # prints --foo=4
  ^echo -foo=$"(2 + 2)" # prints -foo=4
  ^echo foo="(2 + 2)" # prints (no interpolation!) foo=(2 + 2)
  ^echo foo,(2 + 2),bar # prints foo,4,bar
  ```

- Bare word interpolation expands for external command head/args:
  ```nushell
  let name = "exa"
  ~/.cargo/bin/($name) # this works, and expands the tilde
  ^$"~/.cargo/bin/($name)" # this doesn't expand the tilde
  ^echo ~/($name)/* # this glob is expanded
  ^echo $"~/($name)/*" # this isn't expanded
  ```

- Ndots are now supported for the head of an external command
(`^.../foo` works)

- Glob values are now supported for head/args of an external command,
and expanded appropriately:
  ```nushell
  ^("~/.cargo/bin/exa" | into glob) # the tilde is expanded
  ^echo ("*.txt" | into glob) # this glob is expanded
  ```

- `run-external` now works more like any other command, without
expecting a special call convention
  for its args:
  ```nushell
  run-external echo "'foo'"
  # before PR: 'foo'
  # after PR:  foo
  run-external echo "*.txt"
  # before PR: (glob is expanded)
  # after PR:  *.txt
  ```

# Tests + Formatting
Lots of tests added and cleaned up. Some tests that weren't active on
Windows changed to use `nu --testbin cococo` so that they can work.
Added a test for Linux only to make sure tilde expansion of commands
works, because changing `HOME` there causes `~` to reliably change.

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting
- [ ] release notes: make sure to mention the new syntaxes that are
supported

crates/nu-cli/src/syntax_highlight.rs

@@ -138,6 +138,7 @@ impl Highlighter for NuHighlighter {
 
                 FlatShape::Filepath => add_colored_token(&shape.1, next_token),
                 FlatShape::Directory => add_colored_token(&shape.1, next_token),
+                FlatShape::GlobInterpolation => add_colored_token(&shape.1, next_token),
                 FlatShape::GlobPattern => add_colored_token(&shape.1, next_token),
                 FlatShape::Variable(_) | FlatShape::VarDecl(_) => {
                     add_colored_token(&shape.1, next_token)
@@ -452,7 +453,8 @@ fn find_matching_block_end_in_expr(
                 }
             }
 
-            Expr::StringInterpolation(exprs) => exprs.iter().find_map(|expr| {
+            Expr::StringInterpolation(exprs) | Expr::GlobInterpolation(exprs, _) => {
+                exprs.iter().find_map(|expr| {
                     find_matching_block_end_in_expr(
                         line,
                         working_set,
@@ -460,7 +462,8 @@ fn find_matching_block_end_in_expr(
                         global_span_offset,
                         global_cursor_offset,
                     )
-            }),
+                })
+            }
 
             Expr::List(list) => {
                 if expr_last == global_cursor_offset {

crates/nu-color-config/src/shape_color.rs

@@ -20,6 +20,7 @@ pub fn default_shape_color(shape: &str) -> Style {
         "shape_flag" => Style::new().fg(Color::Blue).bold(),
         "shape_float" => Style::new().fg(Color::Purple).bold(),
         "shape_garbage" => Style::new().fg(Color::White).on(Color::Red).bold(),
+        "shape_glob_interpolation" => Style::new().fg(Color::Cyan).bold(),
         "shape_globpattern" => Style::new().fg(Color::Cyan).bold(),
         "shape_int" => Style::new().fg(Color::Purple).bold(),
         "shape_internalcall" => Style::new().fg(Color::Cyan).bold(),

crates/nu-command/src/system/run_external.rs

@@ -1,16 +1,15 @@
 use nu_cmd_base::hook::eval_hook;
 use nu_engine::{command_prelude::*, env_to_strings, get_eval_expression};
+use nu_path::{dots::expand_ndots, expand_tilde};
 use nu_protocol::{
-    ast::{Expr, Expression},
-    did_you_mean,
-    process::ChildProcess,
-    ByteStream, NuGlob, OutDest,
+    ast::Expression, did_you_mean, process::ChildProcess, ByteStream, NuGlob, OutDest,
 };
 use nu_system::ForegroundChild;
 use nu_utils::IgnoreCaseExt;
 use pathdiff::diff_paths;
 use std::{
     borrow::Cow,
+    ffi::{OsStr, OsString},
     io::Write,
     path::{Path, PathBuf},
     process::Stdio,
@@ -33,8 +32,16 @@ impl Command for External {
     fn signature(&self) -> nu_protocol::Signature {
         Signature::build(self.name())
             .input_output_types(vec![(Type::Any, Type::Any)])
-            .required("command", SyntaxShape::String, "External command to run.")
-            .rest("args", SyntaxShape::Any, "Arguments for external command.")
+            .required(
+                "command",
+                SyntaxShape::OneOf(vec![SyntaxShape::GlobPattern, SyntaxShape::String]),
+                "External command to run.",
+            )
+            .rest(
+                "args",
+                SyntaxShape::OneOf(vec![SyntaxShape::GlobPattern, SyntaxShape::Any]),
+                "Arguments for external command.",
+            )
             .category(Category::System)
     }
 
@@ -47,42 +54,31 @@ impl Command for External {
     ) -> Result<PipelineData, ShellError> {
         let cwd = engine_state.cwd(Some(stack))?;
 
-        // Evaluate the command name in the same way the arguments are evaluated. Since this isn't
-        // a spread, it should return a one-element vec.
-        let name_expr = call
-            .positional_nth(0)
-            .ok_or_else(|| ShellError::MissingParameter {
-                param_name: "command".into(),
-                span: call.head,
-            })?;
-        let name = eval_argument(engine_state, stack, name_expr, false)?
-            .pop()
-            .expect("eval_argument returned zero-element vec")
-            .into_spanned(name_expr.span);
+        let name: Value = call.req(engine_state, stack, 0)?;
+
+        let name_str: Cow<str> = match &name {
+            Value::Glob { val, .. } => Cow::Borrowed(val),
+            Value::String { val, .. } => Cow::Borrowed(val),
+            _ => Cow::Owned(name.clone().coerce_into_string()?),
+        };
+
+        let expanded_name = match &name {
+            // Expand tilde and ndots on the name if it's a bare string / glob (#13000)
+            Value::Glob { no_expand, .. } if !*no_expand => expand_ndots(expand_tilde(&*name_str)),
+            _ => Path::new(&*name_str).to_owned(),
+        };
 
         // Find the absolute path to the executable. On Windows, set the
         // executable to "cmd.exe" if it's is a CMD internal command. If the
         // command is not found, display a helpful error message.
-        let executable = if cfg!(windows) && is_cmd_internal_command(&name.item) {
+        let executable = if cfg!(windows) && is_cmd_internal_command(&name_str) {
             PathBuf::from("cmd.exe")
         } else {
-            // Expand tilde on the name if it's a bare string (#13000)
-            let expanded_name = if is_bare_string(name_expr) {
-                expand_tilde(&name.item)
-            } else {
-                name.item.clone()
-            };
-
             // Determine the PATH to be used and then use `which` to find it - though this has no
             // effect if it's an absolute path already
             let paths = nu_engine::env::path_str(engine_state, stack, call.head)?;
-            let Some(executable) = which(&expanded_name, &paths, &cwd) else {
-                return Err(command_not_found(
-                    &name.item,
-                    call.head,
-                    engine_state,
-                    stack,
-                ));
+            let Some(executable) = which(expanded_name, &paths, &cwd) else {
+                return Err(command_not_found(&name_str, call.head, engine_state, stack));
             };
             executable
         };
@@ -101,15 +97,15 @@ impl Command for External {
         // Configure args.
         let args = eval_arguments_from_call(engine_state, stack, call)?;
         #[cfg(windows)]
-        if is_cmd_internal_command(&name.item) {
+        if is_cmd_internal_command(&name_str) {
             use std::os::windows::process::CommandExt;
 
             // The /D flag disables execution of AutoRun commands from registry.
             // The /C flag followed by a command name instructs CMD to execute
             // that command and quit.
-            command.args(["/D", "/C", &name.item]);
+            command.args(["/D", "/C", &name_str]);
             for arg in &args {
-                command.raw_arg(escape_cmd_argument(arg)?.as_ref());
+                command.raw_arg(escape_cmd_argument(arg)?);
             }
         } else {
             command.args(args.into_iter().map(|s| s.item));
@@ -217,76 +213,54 @@ impl Command for External {
     }
 }
 
-/// Removes surrounding quotes from a string. Doesn't remove quotes from raw
-/// strings. Returns the original string if it doesn't have matching quotes.
-fn remove_quotes(s: &str) -> Cow<'_, str> {
-    let quoted_by_double_quotes = s.len() >= 2 && s.starts_with('"') && s.ends_with('"');
-    let quoted_by_single_quotes = s.len() >= 2 && s.starts_with('\'') && s.ends_with('\'');
-    let quoted_by_backticks = s.len() >= 2 && s.starts_with('`') && s.ends_with('`');
-    if quoted_by_double_quotes {
-        Cow::Owned(s[1..s.len() - 1].to_string().replace(r#"\""#, "\""))
-    } else if quoted_by_single_quotes || quoted_by_backticks {
-        Cow::Borrowed(&s[1..s.len() - 1])
-    } else {
-        Cow::Borrowed(s)
-    }
-}
-
 /// Evaluate all arguments from a call, performing expansions when necessary.
 pub fn eval_arguments_from_call(
     engine_state: &EngineState,
     stack: &mut Stack,
     call: &Call,
-) -> Result<Vec<Spanned<String>>, ShellError> {
+) -> Result<Vec<Spanned<OsString>>, ShellError> {
     let ctrlc = &engine_state.ctrlc;
     let cwd = engine_state.cwd(Some(stack))?;
-    let mut args: Vec<Spanned<String>> = vec![];
+    let mut args: Vec<Spanned<OsString>> = vec![];
     for (expr, spread) in call.rest_iter(1) {
-        if is_bare_string(expr) {
-            // If `expr` is a bare string, perform tilde-expansion,
-            // glob-expansion, and inner-quotes-removal, in that order.
         for arg in eval_argument(engine_state, stack, expr, spread)? {
-                let tilde_expanded = expand_tilde(&arg);
-                for glob_expanded in expand_glob(&tilde_expanded, &cwd, expr.span, ctrlc)? {
-                    let inner_quotes_removed = remove_inner_quotes(&glob_expanded);
-                    args.push(inner_quotes_removed.into_owned().into_spanned(expr.span));
+            match arg {
+                // Expand globs passed to run-external
+                Value::Glob { val, no_expand, .. } if !no_expand => args.extend(
+                    expand_glob(&val, &cwd, expr.span, ctrlc)?
+                        .into_iter()
+                        .map(|s| s.into_spanned(expr.span)),
+                ),
+                other => {
+                    args.push(OsString::from(coerce_into_string(other)?).into_spanned(expr.span))
                 }
             }
-        } else {
-            for arg in eval_argument(engine_state, stack, expr, spread)? {
-                args.push(arg.into_spanned(expr.span));
-            }
         }
     }
     Ok(args)
 }
 
-/// Evaluates an expression, coercing the values to strings.
-///
-/// Note: The parser currently has a special hack that retains surrounding
-/// quotes for string literals in `Expression`, so that we can decide whether
-/// the expression is considered a bare string. The hack doesn't affect string
-/// literals within lists or records. This function will remove the quotes
-/// before evaluating the expression.
+/// Custom `coerce_into_string()`, including globs, since those are often args to `run-external`
+/// as well
+fn coerce_into_string(val: Value) -> Result<String, ShellError> {
+    match val {
+        Value::Glob { val, .. } => Ok(val),
+        _ => val.coerce_into_string(),
+    }
+}
+
+/// Evaluate an argument, returning more than one value if it was a list to be spread.
 fn eval_argument(
     engine_state: &EngineState,
     stack: &mut Stack,
     expr: &Expression,
     spread: bool,
-) -> Result<Vec<String>, ShellError> {
-    // Remove quotes from string literals.
-    let mut expr = expr.clone();
-    if let Expr::String(s) = &expr.expr {
-        expr.expr = Expr::String(remove_quotes(s).into());
-    }
-
+) -> Result<Vec<Value>, ShellError> {
     let eval = get_eval_expression(engine_state);
-    match eval(engine_state, stack, &expr)? {
+    match eval(engine_state, stack, expr)? {
         Value::List { vals, .. } => {
             if spread {
-                vals.into_iter()
-                    .map(|val| val.coerce_into_string())
-                    .collect()
+                Ok(vals)
             } else {
                 Err(ShellError::CannotPassListToExternal {
                     arg: String::from_utf8_lossy(engine_state.get_span_contents(expr.span)).into(),
@@ -298,31 +272,12 @@ fn eval_argument(
             if spread {
                 Err(ShellError::CannotSpreadAsList { span: expr.span })
             } else {
-                Ok(vec![value.coerce_into_string()?])
+                Ok(vec![value])
             }
         }
     }
 }
 
-/// Returns whether an expression is considered a bare string.
-///
-/// Bare strings are defined as string literals that are either unquoted or
-/// quoted by backticks. Raw strings or string interpolations don't count.
-fn is_bare_string(expr: &Expression) -> bool {
-    let Expr::String(s) = &expr.expr else {
-        return false;
-    };
-    let quoted_by_double_quotes = s.len() >= 2 && s.starts_with('"') && s.ends_with('"');
-    let quoted_by_single_quotes = s.len() >= 2 && s.starts_with('\'') && s.ends_with('\'');
-    !quoted_by_double_quotes && !quoted_by_single_quotes
-}
-
-/// Performs tilde expansion on `arg`. Returns the original string if `arg`
-/// doesn't start with tilde.
-fn expand_tilde(arg: &str) -> String {
-    nu_path::expand_tilde(arg).to_string_lossy().to_string()
-}
-
 /// Performs glob expansion on `arg`. If the expansion found no matches or the pattern
 /// is not a valid glob, then this returns the original string as the expansion result.
 ///
@@ -333,19 +288,21 @@ fn expand_glob(
     cwd: &Path,
     span: Span,
     interrupt: &Option<Arc<AtomicBool>>,
-) -> Result<Vec<String>, ShellError> {
+) -> Result<Vec<OsString>, ShellError> {
     const GLOB_CHARS: &[char] = &['*', '?', '['];
 
-    // Don't expand something that doesn't include the GLOB_CHARS
+    // For an argument that doesn't include the GLOB_CHARS, just do the `expand_tilde`
+    // and `expand_ndots` expansion
     if !arg.contains(GLOB_CHARS) {
-        return Ok(vec![arg.into()]);
+        let path = expand_ndots(expand_tilde(arg));
+        return Ok(vec![path.into()]);
     }
 
     // We must use `nu_engine::glob_from` here, in order to ensure we get paths from the correct
     // dir
     let glob = NuGlob::Expand(arg.to_owned()).into_spanned(span);
     if let Ok((prefix, matches)) = nu_engine::glob_from(&glob, cwd, span, None) {
-        let mut result = vec![];
+        let mut result: Vec<OsString> = vec![];
 
         for m in matches {
             if nu_utils::ctrl_c::was_pressed(interrupt) {
@@ -353,7 +310,7 @@ fn expand_glob(
             }
             if let Ok(arg) = m {
                 let arg = resolve_globbed_path_to_cwd_relative(arg, prefix.as_ref(), cwd);
-                result.push(arg.to_string_lossy().to_string());
+                result.push(arg.into());
             } else {
                 result.push(arg.into());
             }
@@ -392,23 +349,6 @@ fn resolve_globbed_path_to_cwd_relative(
     }
 }
 
-/// Transforms `--option="value"` into `--option=value`. `value` can be quoted
-/// with double quotes, single quotes, or backticks. Only removes the outermost
-/// pair of quotes after the equal sign.
-fn remove_inner_quotes(arg: &str) -> Cow<'_, str> {
-    // Split `arg` on the first `=`.
-    let Some((option, value)) = arg.split_once('=') else {
-        return Cow::Borrowed(arg);
-    };
-    // Check that `option` doesn't contain quotes.
-    if option.contains('"') || option.contains('\'') || option.contains('`') {
-        return Cow::Borrowed(arg);
-    }
-    // Remove the outermost pair of quotes from `value`.
-    let value = remove_quotes(value);
-    Cow::Owned(format!("{option}={value}"))
-}
-
 /// Write `PipelineData` into `writer`. If `PipelineData` is not binary, it is
 /// first rendered using the `table` command.
 ///
@@ -577,7 +517,7 @@ pub fn command_not_found(
 /// Note: the `which.rs` crate always uses PATHEXT from the environment. As
 /// such, changing PATHEXT within Nushell doesn't work without updating the
 /// actual environment of the Nushell process.
-pub fn which(name: &str, paths: &str, cwd: &Path) -> Option<PathBuf> {
+pub fn which(name: impl AsRef<OsStr>, paths: &str, cwd: &Path) -> Option<PathBuf> {
     #[cfg(windows)]
     let paths = format!("{};{}", cwd.display(), paths);
     which::which_in(name, Some(paths), cwd).ok()
@@ -593,17 +533,18 @@ fn is_cmd_internal_command(name: &str) -> bool {
 }
 
 /// Returns true if a string contains CMD special characters.
-#[cfg(windows)]
-fn has_cmd_special_character(s: &str) -> bool {
-    const SPECIAL_CHARS: &[char] = &['<', '>', '&', '|', '^'];
-    SPECIAL_CHARS.iter().any(|c| s.contains(*c))
+fn has_cmd_special_character(s: impl AsRef<[u8]>) -> bool {
+    s.as_ref()
+        .iter()
+        .any(|b| matches!(b, b'<' | b'>' | b'&' | b'|' | b'^'))
 }
 
 /// Escape an argument for CMD internal commands. The result can be safely passed to `raw_arg()`.
-#[cfg(windows)]
-fn escape_cmd_argument(arg: &Spanned<String>) -> Result<Cow<'_, str>, ShellError> {
+#[cfg_attr(not(windows), allow(dead_code))]
+fn escape_cmd_argument(arg: &Spanned<OsString>) -> Result<Cow<'_, OsStr>, ShellError> {
     let Spanned { item: arg, span } = arg;
-    if arg.contains(['\r', '\n', '%']) {
+    let bytes = arg.as_encoded_bytes();
+    if bytes.iter().any(|b| matches!(b, b'\r' | b'\n' | b'%')) {
         // \r and \n trunacte the rest of the arguments and % can expand environment variables
         Err(ShellError::ExternalCommand {
             label:
@@ -612,12 +553,12 @@ fn escape_cmd_argument(arg: &Spanned<String>) -> Result<Cow<'_, str>, ShellError
             help: "some characters currently cannot be securely escaped".into(),
             span: *span,
         })
-    } else if arg.contains('"') {
+    } else if bytes.contains(&b'"') {
         // If `arg` is already quoted by double quotes, confirm there's no
         // embedded double quotes, then leave it as is.
-        if arg.chars().filter(|c| *c == '"').count() == 2
-            && arg.starts_with('"')
-            && arg.ends_with('"')
+        if bytes.iter().filter(|b| **b == b'"').count() == 2
+            && bytes.starts_with(b"\"")
+            && bytes.ends_with(b"\"")
         {
             Ok(Cow::Borrowed(arg))
         } else {
@@ -628,9 +569,13 @@ fn escape_cmd_argument(arg: &Spanned<String>) -> Result<Cow<'_, str>, ShellError
                 span: *span,
             })
         }
-    } else if arg.contains(' ') || has_cmd_special_character(arg) {
+    } else if bytes.contains(&b' ') || has_cmd_special_character(bytes) {
         // If `arg` contains space or special characters, quote the entire argument by double quotes.
-        Ok(Cow::Owned(format!("\"{arg}\"")))
+        let mut new_str = OsString::new();
+        new_str.push("\"");
+        new_str.push(arg);
+        new_str.push("\"");
+        Ok(Cow::Owned(new_str))
     } else {
         // FIXME?: what if `arg.is_empty()`?
         Ok(Cow::Borrowed(arg))
@@ -640,64 +585,8 @@ fn escape_cmd_argument(arg: &Spanned<String>) -> Result<Cow<'_, str>, ShellError
 #[cfg(test)]
 mod test {
     use super::*;
-    use nu_protocol::ast::ListItem;
     use nu_test_support::{fs::Stub, playground::Playground};
 
-    #[test]
-    fn test_remove_quotes() {
-        assert_eq!(remove_quotes(r#""#), r#""#);
-        assert_eq!(remove_quotes(r#"'"#), r#"'"#);
-        assert_eq!(remove_quotes(r#"''"#), r#""#);
-        assert_eq!(remove_quotes(r#""foo""#), r#"foo"#);
-        assert_eq!(remove_quotes(r#"`foo '"' bar`"#), r#"foo '"' bar"#);
-        assert_eq!(remove_quotes(r#"'foo' bar"#), r#"'foo' bar"#);
-        assert_eq!(remove_quotes(r#"r#'foo'#"#), r#"r#'foo'#"#);
-        assert_eq!(remove_quotes(r#""foo\" bar""#), r#"foo" bar"#);
-    }
-
-    #[test]
-    fn test_eval_argument() {
-        fn expression(expr: Expr) -> Expression {
-            Expression::new_unknown(expr, Span::unknown(), Type::Any)
-        }
-
-        fn eval(expr: Expr, spread: bool) -> Result<Vec<String>, ShellError> {
-            let engine_state = EngineState::new();
-            let mut stack = Stack::new();
-            eval_argument(&engine_state, &mut stack, &expression(expr), spread)
-        }
-
-        let actual = eval(Expr::String("".into()), false).unwrap();
-        let expected = &[""];
-        assert_eq!(actual, expected);
-
-        let actual = eval(Expr::String("'foo'".into()), false).unwrap();
-        let expected = &["foo"];
-        assert_eq!(actual, expected);
-
-        let actual = eval(Expr::RawString("'foo'".into()), false).unwrap();
-        let expected = &["'foo'"];
-        assert_eq!(actual, expected);
-
-        let actual = eval(Expr::List(vec![]), true).unwrap();
-        let expected: &[&str] = &[];
-        assert_eq!(actual, expected);
-
-        let actual = eval(
-            Expr::List(vec![
-                ListItem::Item(expression(Expr::String("'foo'".into()))),
-                ListItem::Item(expression(Expr::String("bar".into()))),
-            ]),
-            true,
-        )
-        .unwrap();
-        let expected = &["'foo'", "bar"];
-        assert_eq!(actual, expected);
-
-        eval(Expr::String("".into()), true).unwrap_err();
-        eval(Expr::List(vec![]), false).unwrap_err();
-    }
-
     #[test]
     fn test_expand_glob() {
         Playground::setup("test_expand_glob", |dirs, play| {
@@ -721,46 +610,20 @@ mod test {
             assert_eq!(actual, expected);
 
             let actual = expand_glob("./a.txt", cwd, Span::unknown(), &None).unwrap();
-            let expected = &["./a.txt"];
+            let expected: Vec<OsString> = vec![Path::new(".").join("a.txt").into()];
             assert_eq!(actual, expected);
 
             let actual = expand_glob("[*.txt", cwd, Span::unknown(), &None).unwrap();
             let expected = &["[*.txt"];
             assert_eq!(actual, expected);
+
+            let actual = expand_glob("~/foo.txt", cwd, Span::unknown(), &None).unwrap();
+            let home = dirs_next::home_dir().expect("failed to get home dir");
+            let expected: Vec<OsString> = vec![home.join("foo.txt").into()];
+            assert_eq!(actual, expected);
         })
     }
 
-    #[test]
-    fn test_remove_inner_quotes() {
-        let actual = remove_inner_quotes(r#"--option=value"#);
-        let expected = r#"--option=value"#;
-        assert_eq!(actual, expected);
-
-        let actual = remove_inner_quotes(r#"--option="value""#);
-        let expected = r#"--option=value"#;
-        assert_eq!(actual, expected);
-
-        let actual = remove_inner_quotes(r#"--option='value'"#);
-        let expected = r#"--option=value"#;
-        assert_eq!(actual, expected);
-
-        let actual = remove_inner_quotes(r#"--option "value""#);
-        let expected = r#"--option "value""#;
-        assert_eq!(actual, expected);
-
-        let actual = remove_inner_quotes(r#"-option="value""#);
-        let expected = r#"-option=value"#;
-        assert_eq!(actual, expected);
-
-        let actual = remove_inner_quotes(r#"option="value""#);
-        let expected = r#"option=value"#;
-        assert_eq!(actual, expected);
-
-        let actual = remove_inner_quotes(r#"option="v\"value""#);
-        let expected = r#"option=v"value"#;
-        assert_eq!(actual, expected);
-    }
-
     #[test]
     fn test_write_pipeline_data() {
         let engine_state = EngineState::new();

crates/nu-command/tests/commands/run_external.rs

@@ -1,4 +1,3 @@
-#[cfg(not(windows))]
 use nu_test_support::fs::Stub::EmptyFile;
 use nu_test_support::playground::Playground;
 use nu_test_support::{nu, pipeline};
@@ -17,7 +16,6 @@ fn better_empty_redirection() {
     assert!(!actual.out.contains('2'));
 }
 
-#[cfg(not(windows))]
 #[test]
 fn explicit_glob() {
     Playground::setup("external with explicit glob", |dirs, sandbox| {
@@ -30,15 +28,15 @@ fn explicit_glob() {
         let actual = nu!(
             cwd: dirs.test(), pipeline(
             r#"
-                ^ls | glob '*.txt' | length
+                ^nu --testbin cococo ('*.txt' | into glob)
             "#
         ));
 
-        assert_eq!(actual.out, "2");
+        assert!(actual.out.contains("D&D_volume_1.txt"));
+        assert!(actual.out.contains("D&D_volume_2.txt"));
     })
 }
 
-#[cfg(not(windows))]
 #[test]
 fn bare_word_expand_path_glob() {
     Playground::setup("bare word should do the expansion", |dirs, sandbox| {
@@ -51,7 +49,7 @@ fn bare_word_expand_path_glob() {
         let actual = nu!(
             cwd: dirs.test(), pipeline(
             "
-                ^ls *.txt
+                ^nu --testbin cococo *.txt
             "
         ));
 
@@ -60,7 +58,6 @@ fn bare_word_expand_path_glob() {
     })
 }
 
-#[cfg(not(windows))]
 #[test]
 fn backtick_expand_path_glob() {
     Playground::setup("backtick should do the expansion", |dirs, sandbox| {
@@ -73,7 +70,7 @@ fn backtick_expand_path_glob() {
         let actual = nu!(
             cwd: dirs.test(), pipeline(
             r#"
-                ^ls `*.txt`
+                ^nu --testbin cococo `*.txt`
             "#
         ));
 
@@ -82,7 +79,6 @@ fn backtick_expand_path_glob() {
     })
 }
 
-#[cfg(not(windows))]
 #[test]
 fn single_quote_does_not_expand_path_glob() {
     Playground::setup("single quote do not run the expansion", |dirs, sandbox| {
@@ -95,15 +91,14 @@ fn single_quote_does_not_expand_path_glob() {
         let actual = nu!(
             cwd: dirs.test(), pipeline(
             r#"
-                ^ls '*.txt'
+                ^nu --testbin cococo '*.txt'
             "#
         ));
 
-        assert!(actual.err.contains("No such file or directory"));
+        assert_eq!(actual.out, "*.txt");
     })
 }
 
-#[cfg(not(windows))]
 #[test]
 fn double_quote_does_not_expand_path_glob() {
     Playground::setup("double quote do not run the expansion", |dirs, sandbox| {
@@ -116,22 +111,21 @@ fn double_quote_does_not_expand_path_glob() {
         let actual = nu!(
             cwd: dirs.test(), pipeline(
             r#"
-                ^ls "*.txt"
+                ^nu --testbin cococo "*.txt"
             "#
         ));
 
-        assert!(actual.err.contains("No such file or directory"));
+        assert_eq!(actual.out, "*.txt");
     })
 }
 
-#[cfg(not(windows))]
 #[test]
 fn failed_command_with_semicolon_will_not_execute_following_cmds() {
     Playground::setup("external failed command with semicolon", |dirs, _| {
         let actual = nu!(
             cwd: dirs.test(), pipeline(
             "
-                ^ls *.abc; echo done
+                nu --testbin fail; echo done
             "
         ));
 
@@ -155,16 +149,51 @@ fn external_args_with_quoted() {
 
 #[cfg(not(windows))]
 #[test]
-fn external_arg_with_long_flag_value_quoted() {
-    Playground::setup("external failed command with semicolon", |dirs, _| {
+fn external_arg_with_option_like_embedded_quotes() {
+    // TODO: would be nice to make this work with cococo, but arg parsing interferes
+    Playground::setup(
+        "external arg with option like embedded quotes",
+        |dirs, _| {
             let actual = nu!(
                 cwd: dirs.test(), pipeline(
                 r#"
-                ^echo --foo='bar'
+                ^echo --foo='bar' -foo='bar'
             "#
             ));
 
-        assert_eq!(actual.out, "--foo=bar");
+            assert_eq!(actual.out, "--foo=bar -foo=bar");
+        },
+    )
+}
+
+#[test]
+fn external_arg_with_non_option_like_embedded_quotes() {
+    Playground::setup(
+        "external arg with non option like embedded quotes",
+        |dirs, _| {
+            let actual = nu!(
+                cwd: dirs.test(), pipeline(
+                r#"
+                ^nu --testbin cococo foo='bar' 'foo'=bar
+            "#
+            ));
+
+            assert_eq!(actual.out, "foo=bar foo=bar");
+        },
+    )
+}
+
+#[test]
+fn external_arg_with_string_interpolation() {
+    Playground::setup("external arg with string interpolation", |dirs, _| {
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                ^nu --testbin cococo foo=(2 + 2) $"foo=(2 + 2)" foo=$"(2 + 2)"
+            "#
+        ));
+
+        assert_eq!(actual.out, "foo=4 foo=4 foo=4");
     })
 }
 
@@ -200,6 +229,67 @@ fn external_command_escape_args() {
     })
 }
 
+#[test]
+#[cfg_attr(
+    not(target_os = "linux"),
+    ignore = "only runs on Linux, where controlling the HOME var is reliable"
+)]
+fn external_command_expand_tilde() {
+    Playground::setup("external command expand tilde", |dirs, _| {
+        // Make a copy of the nu executable that we can use
+        let mut src = std::fs::File::open(nu_test_support::fs::binaries().join("nu"))
+            .expect("failed to open nu");
+        let mut dst = std::fs::File::create_new(dirs.test().join("test_nu"))
+            .expect("failed to create test_nu file");
+        std::io::copy(&mut src, &mut dst).expect("failed to copy data for nu binary");
+
+        // Make test_nu have the same permissions so that it's executable
+        dst.set_permissions(
+            src.metadata()
+                .expect("failed to get nu metadata")
+                .permissions(),
+        )
+        .expect("failed to set permissions on test_nu");
+
+        // Close the files
+        drop(dst);
+        drop(src);
+
+        let actual = nu!(
+            envs: vec![
+                ("HOME".to_string(), dirs.test().to_string_lossy().into_owned()),
+            ],
+            r#"
+                ^~/test_nu --testbin cococo hello
+            "#
+        );
+        assert_eq!(actual.out, "hello");
+    })
+}
+
+#[test]
+fn external_arg_expand_tilde() {
+    Playground::setup("external arg expand tilde", |dirs, _| {
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                ^nu --testbin cococo ~/foo ~/(2 + 2)
+            "#
+        ));
+
+        let home = dirs_next::home_dir().expect("failed to find home dir");
+
+        assert_eq!(
+            actual.out,
+            format!(
+                "{} {}",
+                home.join("foo").display(),
+                home.join("4").display()
+            )
+        );
+    })
+}
+
 #[test]
 fn external_command_not_expand_tilde_with_quotes() {
     Playground::setup(
@@ -231,21 +321,6 @@ fn external_command_receives_raw_binary_data() {
     })
 }
 
-#[cfg(windows)]
-#[test]
-fn failed_command_with_semicolon_will_not_execute_following_cmds_windows() {
-    Playground::setup("external failed command with semicolon", |dirs, _| {
-        let actual = nu!(
-            cwd: dirs.test(), pipeline(
-            "
-                ^cargo asdf; echo done
-            "
-        ));
-
-        assert!(!actual.out.contains("done"));
-    })
-}
-
 #[cfg(windows)]
 #[test]
 fn can_run_batch_files() {

crates/nu-parser/src/flatten.rs

@@ -26,6 +26,7 @@ pub enum FlatShape {
     Flag,
     Float,
     Garbage,
+    GlobInterpolation,
     GlobPattern,
     Int,
     InternalCall(DeclId),
@@ -67,6 +68,7 @@ impl FlatShape {
             FlatShape::Flag => "shape_flag",
             FlatShape::Float => "shape_float",
             FlatShape::Garbage => "shape_garbage",
+            FlatShape::GlobInterpolation => "shape_glob_interpolation",
             FlatShape::GlobPattern => "shape_globpattern",
             FlatShape::Int => "shape_int",
             FlatShape::InternalCall(_) => "shape_internalcall",
@@ -277,7 +279,7 @@ fn flatten_expression_into(
             output[arg_start..].sort();
         }
         Expr::ExternalCall(head, args) => {
-            if let Expr::String(..) = &head.expr {
+            if let Expr::String(..) | Expr::GlobPattern(..) = &head.expr {
                 output.push((head.span, FlatShape::External));
             } else {
                 flatten_expression_into(working_set, head, output);
@@ -286,7 +288,7 @@ fn flatten_expression_into(
             for arg in args.as_ref() {
                 match arg {
                     ExternalArgument::Regular(expr) => {
-                        if let Expr::String(..) = &expr.expr {
+                        if let Expr::String(..) | Expr::GlobPattern(..) = &expr.expr {
                             output.push((expr.span, FlatShape::ExternalArg));
                         } else {
                             flatten_expression_into(working_set, expr, output);
@@ -431,6 +433,25 @@ fn flatten_expression_into(
             }
             output.extend(flattened);
         }
+        Expr::GlobInterpolation(exprs, quoted) => {
+            let mut flattened = vec![];
+            for expr in exprs {
+                flatten_expression_into(working_set, expr, &mut flattened);
+            }
+
+            if *quoted {
+                // If we aren't a bare word interpolation, also highlight the outer quotes
+                output.push((
+                    Span::new(expr.span.start, expr.span.start + 2),
+                    FlatShape::GlobInterpolation,
+                ));
+                flattened.push((
+                    Span::new(expr.span.end - 1, expr.span.end),
+                    FlatShape::GlobInterpolation,
+                ));
+            }
+            output.extend(flattened);
+        }
         Expr::Record(list) => {
             let outer_span = expr.span;
             let mut last_end = outer_span.start;

crates/nu-parser/src/parser.rs

@@ -16,7 +16,6 @@ use nu_protocol::{
     IN_VARIABLE_ID,
 };
 use std::{
-    borrow::Cow,
     collections::{HashMap, HashSet},
     num::ParseIntError,
     str,
@@ -222,6 +221,209 @@ pub(crate) fn check_call(
     }
 }
 
+/// Parses a string in the arg or head position of an external call.
+///
+/// If the string begins with `r#`, it is parsed as a raw string. If it doesn't contain any quotes
+/// or parentheses, it is parsed as a glob pattern so that tilde and glob expansion can be handled
+/// by `run-external`. Otherwise, we use a custom state machine to put together an interpolated
+/// string, where each balanced pair of quotes is parsed as a separate part of the string, and then
+/// concatenated together.
+///
+/// For example, `-foo="bar\nbaz"` becomes `$"-foo=bar\nbaz"`
+fn parse_external_string(working_set: &mut StateWorkingSet, span: Span) -> Expression {
+    let contents = &working_set.get_span_contents(span);
+
+    if contents.starts_with(b"r#") {
+        parse_raw_string(working_set, span)
+    } else if contents
+        .iter()
+        .any(|b| matches!(b, b'"' | b'\'' | b'(' | b')'))
+    {
+        enum State {
+            Bare {
+                from: usize,
+            },
+            Quote {
+                from: usize,
+                quote_char: u8,
+                escaped: bool,
+                depth: i32,
+            },
+        }
+        // Find the spans of parts of the string that can be parsed as their own strings for
+        // concatenation.
+        //
+        // By passing each of these parts to `parse_string()`, we can eliminate the quotes and also
+        // handle string interpolation.
+        let make_span = |from: usize, index: usize| Span {
+            start: span.start + from,
+            end: span.start + index,
+        };
+        let mut spans = vec![];
+        let mut state = State::Bare { from: 0 };
+        let mut index = 0;
+        while index < contents.len() {
+            let ch = contents[index];
+            match &mut state {
+                State::Bare { from } => match ch {
+                    b'"' | b'\'' => {
+                        // Push bare string
+                        if index != *from {
+                            spans.push(make_span(*from, index));
+                        }
+                        // then transition to other state
+                        state = State::Quote {
+                            from: index,
+                            quote_char: ch,
+                            escaped: false,
+                            depth: 1,
+                        };
+                    }
+                    b'$' => {
+                        if let Some(&quote_char @ (b'"' | b'\'')) = contents.get(index + 1) {
+                            // Start a dollar quote (interpolated string)
+                            if index != *from {
+                                spans.push(make_span(*from, index));
+                            }
+                            state = State::Quote {
+                                from: index,
+                                quote_char,
+                                escaped: false,
+                                depth: 1,
+                            };
+                            // Skip over two chars (the dollar sign and the quote)
+                            index += 2;
+                            continue;
+                        }
+                    }
+                    // Continue to consume
+                    _ => (),
+                },
+                State::Quote {
+                    from,
+                    quote_char,
+                    escaped,
+                    depth,
+                } => match ch {
+                    ch if ch == *quote_char && !*escaped => {
+                        // Count if there are more than `depth` quotes remaining
+                        if contents[index..]
+                            .iter()
+                            .filter(|b| *b == quote_char)
+                            .count() as i32
+                            > *depth
+                        {
+                            // Increment depth to be greedy
+                            *depth += 1;
+                        } else {
+                            // Decrement depth
+                            *depth -= 1;
+                        }
+                        if *depth == 0 {
+                            // End of string
+                            spans.push(make_span(*from, index + 1));
+                            // go back to Bare state
+                            state = State::Bare { from: index + 1 };
+                        }
+                    }
+                    b'\\' if !*escaped && *quote_char == b'"' => {
+                        // The next token is escaped so it doesn't count (only for double quote)
+                        *escaped = true;
+                    }
+                    _ => {
+                        *escaped = false;
+                    }
+                },
+            }
+            index += 1;
+        }
+
+        // Add the final span
+        match state {
+            State::Bare { from } | State::Quote { from, .. } => {
+                if from < contents.len() {
+                    spans.push(make_span(from, contents.len()));
+                }
+            }
+        }
+
+        // Log the spans that will be parsed
+        if log::log_enabled!(log::Level::Trace) {
+            let contents = spans
+                .iter()
+                .map(|span| String::from_utf8_lossy(working_set.get_span_contents(*span)))
+                .collect::<Vec<_>>();
+
+            trace!("parsing: external string, parts: {contents:?}")
+        }
+
+        // Check if the whole thing is quoted. If not, it should be a glob
+        let quoted =
+            (contents.len() >= 3 && contents.starts_with(b"$\"") && contents.ends_with(b"\""))
+                || is_quoted(contents);
+
+        // Parse each as its own string
+        let exprs: Vec<Expression> = spans
+            .into_iter()
+            .map(|span| parse_string(working_set, span))
+            .collect();
+
+        if exprs
+            .iter()
+            .all(|expr| matches!(expr.expr, Expr::String(..)))
+        {
+            // If the exprs are all strings anyway, just collapse into a single string.
+            let string = exprs
+                .into_iter()
+                .map(|expr| {
+                    let Expr::String(contents) = expr.expr else {
+                        unreachable!("already checked that this was a String")
+                    };
+                    contents
+                })
+                .collect::<String>();
+            if quoted {
+                Expression::new(working_set, Expr::String(string), span, Type::String)
+            } else {
+                Expression::new(
+                    working_set,
+                    Expr::GlobPattern(string, false),
+                    span,
+                    Type::Glob,
+                )
+            }
+        } else {
+            // Flatten any string interpolations contained with the exprs.
+            let exprs = exprs
+                .into_iter()
+                .flat_map(|expr| match expr.expr {
+                    Expr::StringInterpolation(subexprs) => subexprs,
+                    _ => vec![expr],
+                })
+                .collect();
+            // Make an interpolation out of the expressions. Use `GlobInterpolation` if it's a bare
+            // word, so that the unquoted state can get passed through to `run-external`.
+            if quoted {
+                Expression::new(
+                    working_set,
+                    Expr::StringInterpolation(exprs),
+                    span,
+                    Type::String,
+                )
+            } else {
+                Expression::new(
+                    working_set,
+                    Expr::GlobInterpolation(exprs, false),
+                    span,
+                    Type::Glob,
+                )
+            }
+        }
+    } else {
+        parse_glob_pattern(working_set, span)
+    }
+}
+
 fn parse_external_arg(working_set: &mut StateWorkingSet, span: Span) -> ExternalArgument {
     let contents = working_set.get_span_contents(span);
 
@@ -229,8 +431,6 @@ fn parse_external_arg(working_set: &mut StateWorkingSet, span: Span) -> External
         ExternalArgument::Regular(parse_dollar_expr(working_set, span))
     } else if contents.starts_with(b"[") {
         ExternalArgument::Regular(parse_list_expression(working_set, span, &SyntaxShape::Any))
-    } else if contents.starts_with(b"r#") {
-        ExternalArgument::Regular(parse_raw_string(working_set, span))
     } else if contents.len() > 3
         && contents.starts_with(b"...")
         && (contents[3] == b'$' || contents[3] == b'[' || contents[3] == b'(')
@@ -241,18 +441,7 @@ fn parse_external_arg(working_set: &mut StateWorkingSet, span: Span) -> External
             &SyntaxShape::List(Box::new(SyntaxShape::Any)),
         ))
     } else {
-        // Eval stage trims the quotes, so we don't have to do the same thing when parsing.
-        let (contents, err) = unescape_string_preserving_quotes(contents, span);
-        if let Some(err) = err {
-            working_set.error(err);
-        }
-
-        ExternalArgument::Regular(Expression::new(
-            working_set,
-            Expr::String(contents),
-            span,
-            Type::String,
-        ))
+        ExternalArgument::Regular(parse_external_string(working_set, span))
     }
 }
 
@@ -274,18 +463,7 @@ pub fn parse_external_call(working_set: &mut StateWorkingSet, spans: &[Span]) ->
         let arg = parse_expression(working_set, &[head_span]);
         Box::new(arg)
     } else {
-        // Eval stage will unquote the string, so we don't bother with that here
-        let (contents, err) = unescape_string_preserving_quotes(&head_contents, head_span);
-        if let Some(err) = err {
-            working_set.error(err)
-        }
-
-        Box::new(Expression::new(
-            working_set,
-            Expr::String(contents),
-            head_span,
-            Type::String,
-        ))
+        Box::new(parse_external_string(working_set, head_span))
     };
 
     let args = spans[1..]
@@ -2639,23 +2817,6 @@ pub fn unescape_unquote_string(bytes: &[u8], span: Span) -> (String, Option<Pars
     }
 }
 
-/// XXX: This is here temporarily as a patch, but we should replace this with properly representing
-/// the quoted state of a string in the AST
-fn unescape_string_preserving_quotes(bytes: &[u8], span: Span) -> (String, Option<ParseError>) {
-    let (bytes, err) = if bytes.starts_with(b"\"") {
-        let (bytes, err) = unescape_string(bytes, span);
-        (Cow::Owned(bytes), err)
-    } else {
-        (Cow::Borrowed(bytes), None)
-    };
-
-    // The original code for args used lossy conversion here, even though that's not what we
-    // typically use for strings. Revisit whether that's actually desirable later, but don't
-    // want to introduce a breaking change for this patch.
-    let token = String::from_utf8_lossy(&bytes).into_owned();
-    (token, err)
-}
-
 pub fn parse_string(working_set: &mut StateWorkingSet, span: Span) -> Expression {
     trace!("parsing: string");
 
@@ -6012,7 +6173,7 @@ pub fn discover_captures_in_expr(
         }
         Expr::String(_) => {}
         Expr::RawString(_) => {}
-        Expr::StringInterpolation(exprs) => {
+        Expr::StringInterpolation(exprs) | Expr::GlobInterpolation(exprs, _) => {
             for expr in exprs {
                 discover_captures_in_expr(working_set, expr, seen, seen_blocks, output)?;
             }

crates/nu-parser/tests/test_parser.rs

@@ -1,8 +1,8 @@
 use nu_parser::*;
 use nu_protocol::{
-    ast::{Argument, Call, Expr, ExternalArgument, PathMember, Range},
+    ast::{Argument, Call, Expr, Expression, ExternalArgument, PathMember, Range},
     engine::{Command, EngineState, Stack, StateWorkingSet},
-    ParseError, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    ParseError, PipelineData, ShellError, Signature, Span, SyntaxShape, Type,
 };
 use rstest::rstest;
 
@@ -182,7 +182,7 @@ pub fn multi_test_parse_int() {
         Test(
             "ranges or relative paths not confused for int",
             b"./a/b",
-            Expr::String("./a/b".into()),
+            Expr::GlobPattern("./a/b".into(), false),
             None,
         ),
         Test(
@@ -694,6 +694,50 @@ pub fn parse_call_missing_req_flag() {
     ));
 }
 
+fn test_external_call(input: &str, tag: &str, f: impl FnOnce(&Expression, &[ExternalArgument])) {
+    let engine_state = EngineState::new();
+    let mut working_set = StateWorkingSet::new(&engine_state);
+    let block = parse(&mut working_set, None, input.as_bytes(), true);
+    assert!(
+        working_set.parse_errors.is_empty(),
+        "{tag}: errors: {:?}",
+        working_set.parse_errors
+    );
+
+    let pipeline = &block.pipelines[0];
+    assert_eq!(1, pipeline.len());
+    let element = &pipeline.elements[0];
+    match &element.expr.expr {
+        Expr::ExternalCall(name, args) => f(name, args),
+        other => {
+            panic!("{tag}: Unexpected expression in pipeline: {other:?}");
+        }
+    }
+}
+
+fn check_external_call_interpolation(
+    tag: &str,
+    subexpr_count: usize,
+    quoted: bool,
+    expr: &Expression,
+) -> bool {
+    match &expr.expr {
+        Expr::StringInterpolation(exprs) => {
+            assert!(quoted, "{tag}: quoted");
+            assert_eq!(expr.ty, Type::String, "{tag}: expr.ty");
+            assert_eq!(subexpr_count, exprs.len(), "{tag}: subexpr_count");
+            true
+        }
+        Expr::GlobInterpolation(exprs, is_quoted) => {
+            assert_eq!(quoted, *is_quoted, "{tag}: quoted");
+            assert_eq!(expr.ty, Type::Glob, "{tag}: expr.ty");
+            assert_eq!(subexpr_count, exprs.len(), "{tag}: subexpr_count");
+            true
+        }
+        _ => false,
+    }
+}
+
 #[rstest]
 #[case("foo-external-call", "foo-external-call", "bare word")]
 #[case("^foo-external-call", "foo-external-call", "bare word with caret")]
@@ -713,77 +757,118 @@ pub fn parse_call_missing_req_flag() {
     r"foo\external-call",
     "bare word with backslash and caret"
 )]
-#[case(
-    "^'foo external call'",
-    "'foo external call'",
-    "single quote with caret"
-)]
-#[case(
-    "^'foo/external call'",
-    "'foo/external call'",
-    "single quote with forward slash and caret"
-)]
-#[case(
-    r"^'foo\external call'",
-    r"'foo\external call'",
-    "single quote with backslash and caret"
-)]
-#[case(
-    r#"^"foo external call""#,
-    r#""foo external call""#,
-    "double quote with caret"
-)]
-#[case(
-    r#"^"foo/external call""#,
-    r#""foo/external call""#,
-    "double quote with forward slash and caret"
-)]
-#[case(
-    r#"^"foo\\external call""#,
-    r#""foo\external call""#,
-    "double quote with backslash and caret"
-)]
-#[case("`foo external call`", "`foo external call`", "backtick quote")]
+#[case("`foo external call`", "foo external call", "backtick quote")]
 #[case(
     "^`foo external call`",
-    "`foo external call`",
+    "foo external call",
     "backtick quote with caret"
 )]
 #[case(
     "`foo/external call`",
-    "`foo/external call`",
+    "foo/external call",
     "backtick quote with forward slash"
 )]
 #[case(
     "^`foo/external call`",
-    "`foo/external call`",
+    "foo/external call",
     "backtick quote with forward slash and caret"
 )]
 #[case(
-    r"^`foo\external call`",
     r"`foo\external call`",
+    r"foo\external call",
     "backtick quote with backslash"
 )]
 #[case(
     r"^`foo\external call`",
-    r"`foo\external call`",
+    r"foo\external call",
     "backtick quote with backslash and caret"
 )]
-fn test_external_call_name(#[case] input: &str, #[case] expected: &str, #[case] tag: &str) {
-    let engine_state = EngineState::new();
-    let mut working_set = StateWorkingSet::new(&engine_state);
-    let block = parse(&mut working_set, None, input.as_bytes(), true);
-    assert!(
-        working_set.parse_errors.is_empty(),
-        "{tag}: errors: {:?}",
-        working_set.parse_errors
-    );
+pub fn test_external_call_head_glob(
+    #[case] input: &str,
+    #[case] expected: &str,
+    #[case] tag: &str,
+) {
+    test_external_call(input, tag, |name, args| {
+        match &name.expr {
+            Expr::GlobPattern(string, is_quoted) => {
+                assert_eq!(expected, string, "{tag}: incorrect name");
+                assert!(!*is_quoted);
+            }
+            other => {
+                panic!("{tag}: Unexpected expression in command name position: {other:?}");
+            }
+        }
+        assert_eq!(0, args.len());
+    })
+}
 
-    let pipeline = &block.pipelines[0];
-    assert_eq!(1, pipeline.len());
-    let element = &pipeline.elements[0];
-    match &element.expr.expr {
-        Expr::ExternalCall(name, args) => {
+#[rstest]
+#[case(
+    r##"^r#'foo-external-call'#"##,
+    "foo-external-call",
+    "raw string with caret"
+)]
+#[case(
+    r##"^r#'foo/external-call'#"##,
+    "foo/external-call",
+    "raw string with forward slash and caret"
+)]
+#[case(
+    r##"^r#'foo\external-call'#"##,
+    r"foo\external-call",
+    "raw string with backslash and caret"
+)]
+pub fn test_external_call_head_raw_string(
+    #[case] input: &str,
+    #[case] expected: &str,
+    #[case] tag: &str,
+) {
+    test_external_call(input, tag, |name, args| {
+        match &name.expr {
+            Expr::RawString(string) => {
+                assert_eq!(expected, string, "{tag}: incorrect name");
+            }
+            other => {
+                panic!("{tag}: Unexpected expression in command name position: {other:?}");
+            }
+        }
+        assert_eq!(0, args.len());
+    })
+}
+
+#[rstest]
+#[case("^'foo external call'", "foo external call", "single quote with caret")]
+#[case(
+    "^'foo/external call'",
+    "foo/external call",
+    "single quote with forward slash and caret"
+)]
+#[case(
+    r"^'foo\external call'",
+    r"foo\external call",
+    "single quote with backslash and caret"
+)]
+#[case(
+    r#"^"foo external call""#,
+    r#"foo external call"#,
+    "double quote with caret"
+)]
+#[case(
+    r#"^"foo/external call""#,
+    r#"foo/external call"#,
+    "double quote with forward slash and caret"
+)]
+#[case(
+    r#"^"foo\\external call""#,
+    r#"foo\external call"#,
+    "double quote with backslash and caret"
+)]
+pub fn test_external_call_head_string(
+    #[case] input: &str,
+    #[case] expected: &str,
+    #[case] tag: &str,
+) {
+    test_external_call(input, tag, |name, args| {
         match &name.expr {
             Expr::String(string) => {
                 assert_eq!(expected, string);
@@ -793,47 +878,162 @@ fn test_external_call_name(#[case] input: &str, #[case] expected: &str, #[case]
             }
         }
         assert_eq!(0, args.len());
-        }
-        other => {
-            panic!("{tag}: Unexpected expression in pipeline: {other:?}");
-        }
-    }
+    })
 }
 
 #[rstest]
-#[case("^foo bar-baz", "bar-baz", "bare word")]
-#[case("^foo bar/baz", "bar/baz", "bare word with forward slash")]
-#[case(r"^foo bar\baz", r"bar\baz", "bare word with backslash")]
-#[case("^foo 'bar baz'", "'bar baz'", "single quote")]
-#[case("foo 'bar/baz'", "'bar/baz'", "single quote with forward slash")]
-#[case(r"foo 'bar\baz'", r"'bar\baz'", "single quote with backslash")]
-#[case(r#"^foo "bar baz""#, r#""bar baz""#, "double quote")]
-#[case(r#"^foo "bar/baz""#, r#""bar/baz""#, "double quote with forward slash")]
-#[case(r#"^foo "bar\\baz""#, r#""bar\baz""#, "double quote with backslash")]
-#[case("^foo `bar baz`", "`bar baz`", "backtick quote")]
-#[case("^foo `bar/baz`", "`bar/baz`", "backtick quote with forward slash")]
-#[case(r"^foo `bar\baz`", r"`bar\baz`", "backtick quote with backslash")]
-fn test_external_call_argument_regular(
+#[case(r"~/.foo/(1)", 2, false, "unquoted interpolated string")]
+#[case(
+    r"~\.foo(2)\(1)",
+    4,
+    false,
+    "unquoted interpolated string with backslash"
+)]
+#[case(r"^~/.foo/(1)", 2, false, "unquoted interpolated string with caret")]
+#[case(r#"^$"~/.foo/(1)""#, 2, true, "quoted interpolated string with caret")]
+pub fn test_external_call_head_interpolated_string(
+    #[case] input: &str,
+    #[case] subexpr_count: usize,
+    #[case] quoted: bool,
+    #[case] tag: &str,
+) {
+    test_external_call(input, tag, |name, args| {
+        if !check_external_call_interpolation(tag, subexpr_count, quoted, name) {
+            panic!("{tag}: Unexpected expression in command name position: {name:?}");
+        }
+        assert_eq!(0, args.len());
+    })
+}
+
+#[rstest]
+#[case("^foo foo-external-call", "foo-external-call", "bare word")]
+#[case(
+    "^foo foo/external-call",
+    "foo/external-call",
+    "bare word with forward slash"
+)]
+#[case(
+    r"^foo foo\external-call",
+    r"foo\external-call",
+    "bare word with backslash"
+)]
+#[case(
+    "^foo `foo external call`",
+    "foo external call",
+    "backtick quote with caret"
+)]
+#[case(
+    "^foo `foo/external call`",
+    "foo/external call",
+    "backtick quote with forward slash"
+)]
+#[case(
+    r"^foo `foo\external call`",
+    r"foo\external call",
+    "backtick quote with backslash"
+)]
+pub fn test_external_call_arg_glob(#[case] input: &str, #[case] expected: &str, #[case] tag: &str) {
+    test_external_call(input, tag, |name, args| {
+        match &name.expr {
+            Expr::GlobPattern(string, _) => {
+                assert_eq!("foo", string, "{tag}: incorrect name");
+            }
+            other => {
+                panic!("{tag}: Unexpected expression in command name position: {other:?}");
+            }
+        }
+        assert_eq!(1, args.len());
+        match &args[0] {
+            ExternalArgument::Regular(expr) => match &expr.expr {
+                Expr::GlobPattern(string, is_quoted) => {
+                    assert_eq!(expected, string, "{tag}: incorrect arg");
+                    assert!(!*is_quoted);
+                }
+                other => {
+                    panic!("Unexpected expression in command arg position: {other:?}")
+                }
+            },
+            other @ ExternalArgument::Spread(..) => {
+                panic!("Unexpected external spread argument in command arg position: {other:?}")
+            }
+        }
+    })
+}
+
+#[rstest]
+#[case(r##"^foo r#'foo-external-call'#"##, "foo-external-call", "raw string")]
+#[case(
+    r##"^foo r#'foo/external-call'#"##,
+    "foo/external-call",
+    "raw string with forward slash"
+)]
+#[case(
+    r##"^foo r#'foo\external-call'#"##,
+    r"foo\external-call",
+    "raw string with backslash"
+)]
+pub fn test_external_call_arg_raw_string(
     #[case] input: &str,
     #[case] expected: &str,
     #[case] tag: &str,
 ) {
-    let engine_state = EngineState::new();
-    let mut working_set = StateWorkingSet::new(&engine_state);
-    let block = parse(&mut working_set, None, input.as_bytes(), true);
-    assert!(
-        working_set.parse_errors.is_empty(),
-        "{tag}: errors: {:?}",
-        working_set.parse_errors
-    );
-
-    let pipeline = &block.pipelines[0];
-    assert_eq!(1, pipeline.len());
-    let element = &pipeline.elements[0];
-    match &element.expr.expr {
-        Expr::ExternalCall(name, args) => {
+    test_external_call(input, tag, |name, args| {
         match &name.expr {
-                Expr::String(string) => {
+            Expr::GlobPattern(string, _) => {
+                assert_eq!("foo", string, "{tag}: incorrect name");
+            }
+            other => {
+                panic!("{tag}: Unexpected expression in command name position: {other:?}");
+            }
+        }
+        assert_eq!(1, args.len());
+        match &args[0] {
+            ExternalArgument::Regular(expr) => match &expr.expr {
+                Expr::RawString(string) => {
+                    assert_eq!(expected, string, "{tag}: incorrect arg");
+                }
+                other => {
+                    panic!("Unexpected expression in command arg position: {other:?}")
+                }
+            },
+            other @ ExternalArgument::Spread(..) => {
+                panic!("Unexpected external spread argument in command arg position: {other:?}")
+            }
+        }
+    })
+}
+
+#[rstest]
+#[case("^foo 'foo external call'", "foo external call", "single quote")]
+#[case(
+    "^foo 'foo/external call'",
+    "foo/external call",
+    "single quote with forward slash"
+)]
+#[case(
+    r"^foo 'foo\external call'",
+    r"foo\external call",
+    "single quote with backslash"
+)]
+#[case(r#"^foo "foo external call""#, r#"foo external call"#, "double quote")]
+#[case(
+    r#"^foo "foo/external call""#,
+    r#"foo/external call"#,
+    "double quote with forward slash"
+)]
+#[case(
+    r#"^foo "foo\\external call""#,
+    r#"foo\external call"#,
+    "double quote with backslash"
+)]
+pub fn test_external_call_arg_string(
+    #[case] input: &str,
+    #[case] expected: &str,
+    #[case] tag: &str,
+) {
+    test_external_call(input, tag, |name, args| {
+        match &name.expr {
+            Expr::GlobPattern(string, _) => {
                 assert_eq!("foo", string, "{tag}: incorrect name");
             }
             other => {
@@ -847,38 +1047,58 @@ fn test_external_call_argument_regular(
                     assert_eq!(expected, string, "{tag}: incorrect arg");
                 }
                 other => {
-                        panic!("Unexpected expression in command arg position: {other:?}")
+                    panic!("{tag}: Unexpected expression in command arg position: {other:?}")
                 }
             },
+            other @ ExternalArgument::Spread(..) => {
+                panic!(
+                    "{tag}: Unexpected external spread argument in command arg position: {other:?}"
+                )
+            }
+        }
+    })
+}
+
+#[rstest]
+#[case(r"^foo ~/.foo/(1)", 2, false, "unquoted interpolated string")]
+#[case(r#"^foo $"~/.foo/(1)""#, 2, true, "quoted interpolated string")]
+pub fn test_external_call_arg_interpolated_string(
+    #[case] input: &str,
+    #[case] subexpr_count: usize,
+    #[case] quoted: bool,
+    #[case] tag: &str,
+) {
+    test_external_call(input, tag, |name, args| {
+        match &name.expr {
+            Expr::GlobPattern(string, _) => {
+                assert_eq!("foo", string, "{tag}: incorrect name");
+            }
+            other => {
+                panic!("{tag}: Unexpected expression in command name position: {other:?}");
+            }
+        }
+        assert_eq!(1, args.len());
+        match &args[0] {
+            ExternalArgument::Regular(expr) => {
+                if !check_external_call_interpolation(tag, subexpr_count, quoted, expr) {
+                    panic!("Unexpected expression in command arg position: {expr:?}")
+                }
+            }
             other @ ExternalArgument::Spread(..) => {
                 panic!("Unexpected external spread argument in command arg position: {other:?}")
             }
         }
-        }
-        other => {
-            panic!("{tag}: Unexpected expression in pipeline: {other:?}");
-        }
-    }
+    })
 }
 
 #[test]
 fn test_external_call_argument_spread() {
-    let engine_state = EngineState::new();
-    let mut working_set = StateWorkingSet::new(&engine_state);
-    let block = parse(&mut working_set, None, b"^foo ...[a b c]", true);
-    assert!(
-        working_set.parse_errors.is_empty(),
-        "errors: {:?}",
-        working_set.parse_errors
-    );
+    let input = r"^foo ...[a b c]";
+    let tag = "spread";
 
-    let pipeline = &block.pipelines[0];
-    assert_eq!(1, pipeline.len());
-    let element = &pipeline.elements[0];
-    match &element.expr.expr {
-        Expr::ExternalCall(name, args) => {
+    test_external_call(input, tag, |name, args| {
         match &name.expr {
-                Expr::String(string) => {
+            Expr::GlobPattern(string, _) => {
                 assert_eq!("foo", string, "incorrect name");
             }
             other => {
@@ -897,16 +1117,10 @@ fn test_external_call_argument_spread() {
                 }
             },
             other @ ExternalArgument::Regular(..) => {
-                    panic!(
-                        "Unexpected external regular argument in command arg position: {other:?}"
-                    )
-                }
-            }
-        }
-        other => {
-            panic!("Unexpected expression in pipeline: {other:?}");
+                panic!("Unexpected external regular argument in command arg position: {other:?}")
             }
         }
+    })
 }
 
 #[test]
@@ -1132,6 +1346,44 @@ mod string {
             assert_eq!(subexprs[0], &Expr::String("(1 + 3)(7 - 5)".to_string()));
         }
 
+        #[test]
+        pub fn parse_string_interpolation_bare() {
+            let engine_state = EngineState::new();
+            let mut working_set = StateWorkingSet::new(&engine_state);
+
+            let block = parse(
+                &mut working_set,
+                None,
+                b"\"\" ++ foo(1 + 3)bar(7 - 5)",
+                true,
+            );
+
+            assert!(working_set.parse_errors.is_empty());
+
+            assert_eq!(block.len(), 1);
+            let pipeline = &block.pipelines[0];
+            assert_eq!(pipeline.len(), 1);
+            let element = &pipeline.elements[0];
+            assert!(element.redirection.is_none());
+
+            let subexprs: Vec<&Expr> = match &element.expr.expr {
+                Expr::BinaryOp(_, _, rhs) => match &rhs.expr {
+                    Expr::StringInterpolation(expressions) => {
+                        expressions.iter().map(|e| &e.expr).collect()
+                    }
+                    _ => panic!("Expected an `Expr::StringInterpolation`"),
+                },
+                _ => panic!("Expected an `Expr::BinaryOp`"),
+            };
+
+            assert_eq!(subexprs.len(), 4);
+
+            assert_eq!(subexprs[0], &Expr::String("foo".to_string()));
+            assert!(matches!(subexprs[1], &Expr::FullCellPath(..)));
+            assert_eq!(subexprs[2], &Expr::String("bar".to_string()));
+            assert!(matches!(subexprs[3], &Expr::FullCellPath(..)));
+        }
+
         #[test]
         pub fn parse_nested_expressions() {
             let engine_state = EngineState::new();

crates/nu-protocol/src/ast/expr.rs

@@ -32,8 +32,11 @@ pub enum Expr {
     Keyword(Box<Keyword>),
     ValueWithUnit(Box<ValueWithUnit>),
     DateTime(chrono::DateTime<FixedOffset>),
+    /// The boolean is `true` if the string is quoted.
     Filepath(String, bool),
+    /// The boolean is `true` if the string is quoted.
     Directory(String, bool),
+    /// The boolean is `true` if the string is quoted.
     GlobPattern(String, bool),
     String(String),
     RawString(String),
@@ -43,6 +46,8 @@ pub enum Expr {
     Overlay(Option<BlockId>), // block ID of the overlay's origin module
     Signature(Box<Signature>),
     StringInterpolation(Vec<Expression>),
+    /// The boolean is `true` if the string is quoted.
+    GlobInterpolation(Vec<Expression>, bool),
     Nothing,
     Garbage,
 }
@@ -84,6 +89,7 @@ impl Expr {
             | Expr::RawString(_)
             | Expr::CellPath(_)
             | Expr::StringInterpolation(_)
+            | Expr::GlobInterpolation(_, _)
             | Expr::Nothing => {
                 // These expressions do not use the output of the pipeline in any meaningful way,
                 // so we can discard the previous output by redirecting it to `Null`.

crates/nu-protocol/src/ast/expression.rs

@@ -232,7 +232,7 @@ impl Expression {
                 }
                 false
             }
-            Expr::StringInterpolation(items) => {
+            Expr::StringInterpolation(items) | Expr::GlobInterpolation(items, _) => {
                 for i in items {
                     if i.has_in_variable(working_set) {
                         return true;
@@ -441,7 +441,7 @@ impl Expression {
             Expr::Signature(_) => {}
             Expr::String(_) => {}
             Expr::RawString(_) => {}
-            Expr::StringInterpolation(items) => {
+            Expr::StringInterpolation(items) | Expr::GlobInterpolation(items, _) => {
                 for i in items {
                     i.replace_span(working_set, replaced, new_span)
                 }

crates/nu-protocol/src/debugger/profiler.rs

@@ -258,6 +258,7 @@ fn expr_to_string(engine_state: &EngineState, expr: &Expr) -> String {
         Expr::Signature(_) => "signature".to_string(),
         Expr::String(_) | Expr::RawString(_) => "string".to_string(),
         Expr::StringInterpolation(_) => "string interpolation".to_string(),
+        Expr::GlobInterpolation(_, _) => "glob interpolation".to_string(),
         Expr::Subexpression(_) => "subexpression".to_string(),
         Expr::Table(_) => "table".to_string(),
         Expr::UnaryNot(_) => "unary not".to_string(),

crates/nu-protocol/src/eval_base.rs

@@ -290,6 +290,15 @@ pub trait Eval {
 
                 Ok(Value::string(str, expr_span))
             }
+            Expr::GlobInterpolation(exprs, quoted) => {
+                let config = Self::get_config(state, mut_state);
+                let str = exprs
+                    .iter()
+                    .map(|expr| Self::eval::<D>(state, mut_state, expr).map(|v| v.to_expanded_string(", ", &config)))
+                    .collect::<Result<String, _>>()?;
+
+                Ok(Value::glob(str, *quoted, expr_span))
+            }
             Expr::Overlay(_) => Self::eval_overlay(state, expr_span),
             Expr::GlobPattern(pattern, quoted) => {
                 // GlobPattern is similar to Filepath

crates/nu-test-support/src/macros.rs

@@ -245,6 +245,7 @@ use tempfile::tempdir;
 pub struct NuOpts {
     pub cwd: Option<String>,
     pub locale: Option<String>,
+    pub envs: Option<Vec<(String, String)>>,
     pub collapse_output: Option<bool>,
 }
 
@@ -278,6 +279,11 @@ pub fn nu_run_test(opts: NuOpts, commands: impl AsRef<str>, with_std: bool) -> O
     command
         .env(nu_utils::locale::LOCALE_OVERRIDE_ENV_VAR, locale)
         .env(NATIVE_PATH_ENV_VAR, paths_joined);
+
+    if let Some(envs) = opts.envs {
+        command.envs(envs);
+    }
+
     // Ensure that the user's config doesn't interfere with the tests
     command.arg("--no-config-file");
     if !with_std {

crates/nuon/src/from.rs

@@ -323,6 +323,12 @@ fn convert_to_value(
             msg: "string interpolation not supported in nuon".into(),
             span: expr.span,
         }),
+        Expr::GlobInterpolation(..) => Err(ShellError::OutsideSpannedLabeledError {
+            src: original_text.to_string(),
+            error: "Error when loading".into(),
+            msg: "glob interpolation not supported in nuon".into(),
+            span: expr.span,
+        }),
         Expr::Subexpression(..) => Err(ShellError::OutsideSpannedLabeledError {
             src: original_text.to_string(),
             error: "Error when loading".into(),