Refactor to support multiple parse errors (#8765)

# Description

This is a pretty heavy refactor of the parser to support multiple parser
errors. It has a few issues we should address before landing:

- [x] In some cases, error quality has gotten worse `1 / "bob"` for
example
- [x] if/else isn't currently parsing correctly
- probably others

# User-Facing Changes

This may have error quality degradation as we adjust to the new error
reporting mechanism.

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- crates/nu-utils/standard_library/tests.nu` to run the
tests for the standard library

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-cli/src/commands.rs

@@ -34,9 +34,9 @@ pub fn evaluate_commands(
 
         let mut working_set = StateWorkingSet::new(engine_state);
 
-        let (output, err) = parse(&mut working_set, None, commands.item.as_bytes(), false, &[]);
-        if let Some(err) = err {
-            report_error(&working_set, &err);
+        let output = parse(&mut working_set, None, commands.item.as_bytes(), false, &[]);
+        if let Some(err) = working_set.parse_errors.first() {
+            report_error(&working_set, err);
 
             std::process::exit(1);
         }

crates/nu-cli/src/completions/completer.rs

@@ -120,7 +120,7 @@ impl NuCompleter {
         let pos = offset + pos;
         let config = self.engine_state.get_config();
 
-        let (output, _err) = parse(&mut working_set, Some("completer"), &new_line, false, &[]);
+        let output = parse(&mut working_set, Some("completer"), &new_line, false, &[]);
 
         for pipeline in output.pipelines.into_iter() {
             for pipeline_element in pipeline.elements {

crates/nu-cli/src/config_files.rs

@@ -1,14 +1,12 @@
 use crate::util::eval_source;
 use nu_command::util::report_error;
 #[cfg(feature = "plugin")]
-use nu_parser::ParseError;
-#[cfg(feature = "plugin")]
 use nu_path::canonicalize_with;
 use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-#[cfg(feature = "plugin")]
-use nu_protocol::Spanned;
 use nu_protocol::{HistoryFileFormat, PipelineData};
 #[cfg(feature = "plugin")]
+use nu_protocol::{ParseError, Spanned};
+#[cfg(feature = "plugin")]
 use nu_utils::utils::perf;
 use std::path::PathBuf;
 

crates/nu-cli/src/reedline_config.rs

@@ -97,7 +97,7 @@ pub(crate) fn add_menus(
         {
             let (block, _) = {
                 let mut working_set = StateWorkingSet::new(&engine_state);
-                let (output, _) = parse(
+                let output = parse(
                     &mut working_set,
                     Some(name), // format!("entry #{}", entry_num)
                     definition.as_bytes(),

crates/nu-cli/src/repl.rs

@@ -789,7 +789,7 @@ pub fn eval_string_with_input(
 ) -> Result<Value, ShellError> {
     let (block, delta) = {
         let mut working_set = StateWorkingSet::new(engine_state);
-        let (output, _) = parse(&mut working_set, None, source.as_bytes(), false, &[]);
+        let output = parse(&mut working_set, None, source.as_bytes(), false, &[]);
 
         (output, working_set.render())
     };

crates/nu-cli/src/syntax_highlight.rs

@@ -18,10 +18,7 @@ impl Highlighter for NuHighlighter {
         trace!("highlighting: {}", line);
 
         let mut working_set = StateWorkingSet::new(&self.engine_state);
-        let block = {
-            let (block, _) = parse(&mut working_set, None, line.as_bytes(), false, &[]);
-            block
-        };
+        let block = parse(&mut working_set, None, line.as_bytes(), false, &[]);
         let (shapes, global_span_offset) = {
             let shapes = flatten_block(&working_set, &block);
             (shapes, self.engine_state.next_span_start())

crates/nu-cli/src/util.rs

@@ -113,7 +113,8 @@ fn gather_env_vars(
                 span,
             }) = parts.get(0)
             {
-                let bytes = engine_state.get_span_contents(span);
+                let mut working_set = StateWorkingSet::new(engine_state);
+                let bytes = working_set.get_span_contents(*span);
 
                 if bytes.len() < 2 {
                     report_capture_error(
@@ -125,9 +126,12 @@ fn gather_env_vars(
                     continue;
                 }
 
-                let (bytes, parse_error) = unescape_unquote_string(bytes, *span);
+                let (bytes, err) = unescape_unquote_string(bytes, *span);
+                if let Some(err) = err {
+                    working_set.error(err);
+                }
 
-                if parse_error.is_some() {
+                if working_set.parse_errors.first().is_some() {
                     report_capture_error(
                         engine_state,
                         &String::from_utf8_lossy(contents),
@@ -153,7 +157,8 @@ fn gather_env_vars(
                 span,
             }) = parts.get(2)
             {
-                let bytes = engine_state.get_span_contents(span);
+                let mut working_set = StateWorkingSet::new(engine_state);
+                let bytes = working_set.get_span_contents(*span);
 
                 if bytes.len() < 2 {
                     report_capture_error(
@@ -165,9 +170,12 @@ fn gather_env_vars(
                     continue;
                 }
 
-                let (bytes, parse_error) = unescape_unquote_string(bytes, *span);
+                let (bytes, err) = unescape_unquote_string(bytes, *span);
+                if let Some(err) = err {
+                    working_set.error(err);
+                }
 
-                if parse_error.is_some() {
+                if working_set.parse_errors.first().is_some() {
                     report_capture_error(
                         engine_state,
                         &String::from_utf8_lossy(contents),
@@ -209,16 +217,16 @@ pub fn eval_source(
 
     let (block, delta) = {
         let mut working_set = StateWorkingSet::new(engine_state);
-        let (output, err) = parse(
+        let output = parse(
             &mut working_set,
             Some(fname), // format!("entry #{}", entry_num)
             source,
             false,
             &[],
         );
-        if let Some(err) = err {
+        if let Some(err) = working_set.parse_errors.first() {
             set_last_exit_code(stack, 1);
-            report_error(&working_set, &err);
+            report_error(&working_set, err);
             return false;
         }
 

crates/nu-cli/src/validation.rs

@@ -1,5 +1,8 @@
-use nu_parser::{parse, ParseError};
-use nu_protocol::engine::{EngineState, StateWorkingSet};
+use nu_parser::parse;
+use nu_protocol::{
+    engine::{EngineState, StateWorkingSet},
+    ParseError,
+};
 use reedline::{ValidationResult, Validator};
 use std::sync::Arc;
 
@@ -10,9 +13,12 @@ pub struct NuValidator {
 impl Validator for NuValidator {
     fn validate(&self, line: &str) -> ValidationResult {
         let mut working_set = StateWorkingSet::new(&self.engine_state);
-        let (_, err) = parse(&mut working_set, None, line.as_bytes(), false, &[]);
+        parse(&mut working_set, None, line.as_bytes(), false, &[]);
 
-        if matches!(err, Some(ParseError::UnexpectedEof(..))) {
+        if matches!(
+            working_set.parse_errors.first(),
+            Some(ParseError::UnexpectedEof(..))
+        ) {
             ValidationResult::Incomplete
         } else {
             ValidationResult::Complete

crates/nu-cli/tests/completions.rs

@@ -663,8 +663,8 @@ fn run_external_completion(block: &str, input: &str) -> Vec<Suggestion> {
     let (dir, _, mut engine_state, mut stack) = new_engine();
     let (_, delta) = {
         let mut working_set = StateWorkingSet::new(&engine_state);
-        let (block, err) = parse(&mut working_set, None, block.as_bytes(), false, &[]);
-        assert!(err.is_none());
+        let block = parse(&mut working_set, None, block.as_bytes(), false, &[]);
+        assert!(working_set.parse_errors.is_empty());
 
         (block, working_set.render())
     };

crates/nu-cli/tests/support/completions_helpers.rs

@@ -146,9 +146,9 @@ pub fn merge_input(
     let (block, delta) = {
         let mut working_set = StateWorkingSet::new(engine_state);
 
-        let (block, err) = parse(&mut working_set, None, input, false, &[]);
+        let block = parse(&mut working_set, None, input, false, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
 
         (block, working_set.render())
     };

crates/nu-cmd-lang/src/example_support.rs

@@ -126,9 +126,9 @@ fn eval_pipeline_without_terminal_expression(
 
 pub fn parse(contents: &str, engine_state: &EngineState) -> (Block, StateDelta) {
     let mut working_set = StateWorkingSet::new(engine_state);
-    let (output, err) = nu_parser::parse(&mut working_set, None, contents.as_bytes(), false, &[]);
+    let output = nu_parser::parse(&mut working_set, None, contents.as_bytes(), false, &[]);
 
-    if let Some(err) = err {
+    if let Some(err) = working_set.parse_errors.first() {
         panic!("test parse error in `{contents}`: {err:?}")
     }
 

crates/nu-command/src/dataframe/test_dataframe.rs

@@ -50,7 +50,7 @@ pub fn test_dataframe(cmds: Vec<Box<dyn Command + 'static>>) {
 
         let (block, delta) = {
             let mut working_set = StateWorkingSet::new(&engine_state);
-            let (output, err) = parse(
+            let output = parse(
                 &mut working_set,
                 None,
                 example.example.as_bytes(),
@@ -58,7 +58,7 @@ pub fn test_dataframe(cmds: Vec<Box<dyn Command + 'static>>) {
                 &[],
             );
 
-            if let Some(err) = err {
+            if let Some(err) = working_set.parse_errors.first() {
                 panic!("test parse error in `{}`: {:?}", example.example, err)
             }
 

crates/nu-command/src/debug/ast.rs

@@ -41,8 +41,10 @@ impl Command for Ast {
         let pipeline: Spanned<String> = call.req(engine_state, stack, 0)?;
         let mut working_set = StateWorkingSet::new(engine_state);
 
-        let (block_output, error_output) =
-            parse(&mut working_set, None, pipeline.item.as_bytes(), false, &[]);
+        let block_output = parse(&mut working_set, None, pipeline.item.as_bytes(), false, &[]);
+
+        let error_output = working_set.parse_errors.first();
+
         let block_value = Value::String {
             val: format!("{block_output:#?}"),
             span: pipeline.span,

crates/nu-command/src/formats/from/nuon.rs

@@ -64,10 +64,9 @@ impl Command for FromNuon {
         let engine_state = engine_state.clone();
 
         let mut working_set = StateWorkingSet::new(&engine_state);
-        let mut error = None;
-        let (mut block, err) =
+
+        let mut block =
             nu_parser::parse(&mut working_set, None, string_input.as_bytes(), false, &[]);
-        error = error.or(err);
 
         if let Some(pipeline) = block.pipelines.get(1) {
             if let Some(element) = pipeline.elements.get(0) {
@@ -146,7 +145,7 @@ impl Command for FromNuon {
             }
         };
 
-        if let Some(err) = error {
+        if let Some(err) = working_set.parse_errors.first() {
             return Err(ShellError::GenericError(
                 "error when parsing nuon text".into(),
                 "could not parse nuon text".into(),

crates/nu-command/src/hook.rs

@@ -166,10 +166,10 @@ pub fn eval_hook(
                                 vars.push((var_id, val));
                             }
 
-                            let (output, err) =
+                            let output =
                                 parse(&mut working_set, Some("hook"), val.as_bytes(), false, &[]);
-                            if let Some(err) = err {
-                                report_error(&working_set, &err);
+                            if let Some(err) = working_set.parse_errors.first() {
+                                report_error(&working_set, err);
 
                                 return Err(ShellError::UnsupportedConfigValue(
                                     "valid source code".into(),

crates/nu-command/src/strings/format/command.rs

@@ -290,8 +290,8 @@ fn format_record(
                 }
             }
             FormatOperation::ValueNeedEval(_col_name, span) => {
-                let (exp, may_parse_err) = parse_expression(working_set, &[*span], &[], false);
-                match may_parse_err {
+                let exp = parse_expression(working_set, &[*span], &[], false);
+                match working_set.parse_errors.first() {
                     None => {
                         let parsed_result = eval_expression(engine_state, stack, &exp);
                         if let Ok(val) = parsed_result {

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

@@ -260,9 +260,14 @@ fn heuristic_parse_file(
     call: &Call,
     is_debug: bool,
 ) -> Result<PipelineData, ShellError> {
-    let (filename, err) = unescape_unquote_string(path.as_bytes(), call.head);
-    if err.is_none() {
-        if let Ok(contents) = std::fs::read(&path) {
+    let starting_error_count = working_set.parse_errors.len();
+    let bytes = working_set.get_span_contents(call.head);
+    let (filename, err) = unescape_unquote_string(bytes, call.head);
+    if let Some(err) = err {
+        working_set.error(err);
+    }
+    if starting_error_count == working_set.parse_errors.len() {
+        if let Ok(contents) = std::fs::read(path) {
             match parse_script(
                 working_set,
                 Some(filename.as_str()),
@@ -314,13 +319,17 @@ fn parse_module(
     let end = working_set.next_span_start();
 
     let new_span = Span::new(start, end);
-    let (_, _, _, err) = parse_module_block(working_set, new_span, filename.as_bytes(), &[]);
+    let starting_error_count = working_set.parse_errors.len();
+    parse_module_block(working_set, new_span, filename.as_bytes(), &[]);
 
-    if err.is_some() {
+    if starting_error_count != working_set.parse_errors.len() {
         if is_debug {
             let msg = format!(
                 r#"Found : {}"#,
-                err.expect("Unable to parse content as module")
+                working_set
+                    .parse_errors
+                    .first()
+                    .expect("Unable to parse content as module")
             );
             Err(ShellError::GenericError(
                 "Failed to parse content".to_string(),
@@ -344,9 +353,16 @@ fn parse_script(
     is_debug: bool,
     span: Span,
 ) -> Result<PipelineData, ShellError> {
-    let (_, err) = parse(working_set, filename, contents, false, &[]);
-    if err.is_some() {
-        let msg = format!(r#"Found : {}"#, err.expect("Unable to parse content"));
+    let starting_error_count = working_set.parse_errors.len();
+    parse(working_set, filename, contents, false, &[]);
+    if starting_error_count != working_set.parse_errors.len() {
+        let msg = format!(
+            r#"Found : {}"#,
+            working_set
+                .parse_errors
+                .first()
+                .expect("Unable to parse content")
+        );
         if is_debug {
             Err(ShellError::GenericError(
                 "Failed to parse content".to_string(),
@@ -369,9 +385,14 @@ fn parse_file_script(
     call: &Call,
     is_debug: bool,
 ) -> Result<PipelineData, ShellError> {
-    let (filename, err) = unescape_unquote_string(path.as_bytes(), call.head);
-    if err.is_none() {
-        if let Ok(contents) = std::fs::read(&path) {
+    let starting_error_count = working_set.parse_errors.len();
+    let bytes = working_set.get_span_contents(call.head);
+    let (filename, err) = unescape_unquote_string(bytes, call.head);
+    if let Some(err) = err {
+        working_set.error(err)
+    }
+    if starting_error_count == working_set.parse_errors.len() {
+        if let Ok(contents) = std::fs::read(path) {
             parse_script(
                 working_set,
                 Some(filename.as_str()),
@@ -393,8 +414,13 @@ fn parse_file_module(
     call: &Call,
     is_debug: bool,
 ) -> Result<PipelineData, ShellError> {
-    let (filename, err) = unescape_unquote_string(path.as_bytes(), call.head);
-    if err.is_none() {
+    let starting_error_count = working_set.parse_errors.len();
+    let bytes = working_set.get_span_contents(call.head);
+    let (filename, err) = unescape_unquote_string(bytes, call.head);
+    if let Some(err) = err {
+        working_set.error(err);
+    }
+    if starting_error_count == working_set.parse_errors.len() {
         if let Ok(contents) = std::fs::read(path) {
             parse_module(working_set, Some(filename), &contents, is_debug, call.head)
         } else {

crates/nu-explore/src/nu_common/command.rs

@@ -55,7 +55,7 @@ fn eval_source2(
 ) -> Result<PipelineData, ShellError> {
     let (mut block, delta) = {
         let mut working_set = StateWorkingSet::new(engine_state);
-        let (output, err) = parse(
+        let output = parse(
             &mut working_set,
             Some(fname), // format!("entry #{}", entry_num)
             source,
@@ -63,7 +63,7 @@ fn eval_source2(
             &[],
         );
 
-        if let Some(err) = err {
+        if let Some(err) = working_set.parse_errors.first() {
             return Err(ShellError::IOError(err.to_string()));
         }
 

crates/nu-parser/src/eval.rs

@@ -1,8 +1,7 @@
-use crate::ParseError;
 use nu_protocol::{
     ast::{Expr, Expression},
     engine::StateWorkingSet,
-    Span, Value,
+    ParseError, Span, Value,
 };
 
 /// Evaluate a constant value at parse time

crates/nu-parser/src/lex.rs

@@ -1,5 +1,4 @@
-use crate::ParseError;
-use nu_protocol::Span;
+use nu_protocol::{ParseError, Span};
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum TokenContents {

crates/nu-parser/src/lib.rs

@@ -1,5 +1,4 @@
 mod deparse;
-mod errors;
 mod eval;
 mod flatten;
 mod known_external;
@@ -11,7 +10,6 @@ mod parser;
 mod type_check;
 
 pub use deparse::{escape_for_script_arg, escape_quote_string};
-pub use errors::ParseError;
 pub use flatten::{
     flatten_block, flatten_expression, flatten_pipeline, flatten_pipeline_element, FlatShape,
 };

crates/nu-parser/src/lite_parser.rs

@@ -1,8 +1,8 @@
 /// Lite parsing converts a flat stream of tokens from the lexer to a syntax element structure that
 /// can be parsed.
-use crate::{ParseError, Token, TokenContents};
+use crate::{Token, TokenContents};
 
-use nu_protocol::{ast::Redirection, Span};
+use nu_protocol::{ast::Redirection, ParseError, Span};
 
 #[derive(Debug)]
 pub struct LiteCommand {

crates/nu-parser/src/parse_patterns.rs

@@ -1,13 +1,13 @@
 use nu_protocol::{
     ast::{Expr, Expression, MatchPattern, Pattern},
     engine::StateWorkingSet,
-    Span, SyntaxShape, Type, VarId,
+    ParseError, Span, SyntaxShape, Type, VarId,
 };
 
 use crate::{
     lex, lite_parse,
     parser::{is_variable, parse_value},
-    LiteElement, ParseError,
+    LiteElement,
 };
 
 pub fn garbage(span: Span) -> MatchPattern {
@@ -17,29 +17,20 @@ pub fn garbage(span: Span) -> MatchPattern {
     }
 }
 
-pub fn parse_match_pattern(
-    working_set: &mut StateWorkingSet,
-    span: Span,
-) -> (Expression, Option<ParseError>) {
+pub fn parse_match_pattern(working_set: &mut StateWorkingSet, span: Span) -> Expression {
     working_set.enter_scope();
-    let (output, err) = parse_pattern(working_set, span);
+    let output = parse_pattern(working_set, span);
     working_set.exit_scope();
 
-    (
-        Expression {
-            expr: Expr::MatchPattern(Box::new(output)),
-            span,
-            ty: Type::Any,
-            custom_completion: None,
-        },
-        err,
-    )
+    Expression {
+        expr: Expr::MatchPattern(Box::new(output)),
+        span,
+        ty: Type::Any,
+        custom_completion: None,
+    }
 }
 
-pub fn parse_pattern(
-    working_set: &mut StateWorkingSet,
-    span: Span,
-) -> (MatchPattern, Option<ParseError>) {
+pub fn parse_pattern(working_set: &mut StateWorkingSet, span: Span) -> MatchPattern {
     let bytes = working_set.get_span_contents(span);
 
     if bytes.starts_with(b"$") {
@@ -52,23 +43,18 @@ pub fn parse_pattern(
         // List pattern
         parse_list_pattern(working_set, span)
     } else if bytes == b"_" {
-        (
-            MatchPattern {
-                pattern: Pattern::IgnoreValue,
-                span,
-            },
-            None,
-        )
+        MatchPattern {
+            pattern: Pattern::IgnoreValue,
+            span,
+        }
     } else {
         // Literal value
-        let (value, error) = parse_value(working_set, span, &SyntaxShape::Any, &[]);
-        (
-            MatchPattern {
-                pattern: Pattern::Value(value),
-                span,
-            },
-            error,
-        )
+        let value = parse_value(working_set, span, &SyntaxShape::Any, &[]);
+
+        MatchPattern {
+            pattern: Pattern::Value(value),
+            span,
+        }
     }
 }
 
@@ -88,34 +74,21 @@ fn parse_variable_pattern_helper(working_set: &mut StateWorkingSet, span: Span)
     }
 }
 
-pub fn parse_variable_pattern(
-    working_set: &mut StateWorkingSet,
-    span: Span,
-) -> (MatchPattern, Option<ParseError>) {
+pub fn parse_variable_pattern(working_set: &mut StateWorkingSet, span: Span) -> MatchPattern {
     if let Some(var_id) = parse_variable_pattern_helper(working_set, span) {
-        (
-            MatchPattern {
-                pattern: Pattern::Variable(var_id),
-                span,
-            },
-            None,
-        )
+        MatchPattern {
+            pattern: Pattern::Variable(var_id),
+            span,
+        }
     } else {
-        (
-            garbage(span),
-            Some(ParseError::Expected("valid variable name".into(), span)),
-        )
+        working_set.error(ParseError::Expected("valid variable name".into(), span));
+        garbage(span)
     }
 }
 
-pub fn parse_list_pattern(
-    working_set: &mut StateWorkingSet,
-    span: Span,
-) -> (MatchPattern, Option<ParseError>) {
+pub fn parse_list_pattern(working_set: &mut StateWorkingSet, span: Span) -> MatchPattern {
     let bytes = working_set.get_span_contents(span);
 
-    let mut error = None;
-
     let mut start = span.start;
     let mut end = span.end;
 
@@ -125,17 +98,21 @@ pub fn parse_list_pattern(
     if bytes.ends_with(b"]") {
         end -= 1;
     } else {
-        error = error.or_else(|| Some(ParseError::Unclosed("]".into(), Span::new(end, end))));
+        working_set.error(ParseError::Unclosed("]".into(), Span::new(end, end)));
     }
 
     let inner_span = Span::new(start, end);
     let source = working_set.get_span_contents(inner_span);
 
     let (output, err) = lex(source, inner_span.start, &[b'\n', b'\r', b','], &[], true);
-    error = error.or(err);
+    if let Some(err) = err {
+        working_set.error(err);
+    }
 
     let (output, err) = lite_parse(&output);
-    error = error.or(err);
+    if let Some(err) = err {
+        working_set.error(err);
+    }
 
     let mut args = vec![];
 
@@ -167,14 +144,13 @@ pub fn parse_list_pattern(
                             break;
                         } else {
                             args.push(garbage(command.parts[spans_idx]));
-                            error = error.or(Some(ParseError::Expected(
+                            working_set.error(ParseError::Expected(
                                 "valid variable name".into(),
                                 command.parts[spans_idx],
-                            )));
+                            ));
                         }
                     } else {
-                        let (arg, err) = parse_pattern(working_set, command.parts[spans_idx]);
-                        error = error.or(err);
+                        let arg = parse_pattern(working_set, command.parts[spans_idx]);
 
                         args.push(arg);
                     };
@@ -185,47 +161,41 @@ pub fn parse_list_pattern(
         }
     }
 
-    (
-        MatchPattern {
-            pattern: Pattern::List(args),
-            span,
-        },
-        error,
-    )
+    MatchPattern {
+        pattern: Pattern::List(args),
+        span,
+    }
 }
 
-pub fn parse_record_pattern(
-    working_set: &mut StateWorkingSet,
-    span: Span,
-) -> (MatchPattern, Option<ParseError>) {
-    let bytes = working_set.get_span_contents(span);
+pub fn parse_record_pattern(working_set: &mut StateWorkingSet, span: Span) -> MatchPattern {
+    let mut bytes = working_set.get_span_contents(span);
 
-    let mut error = None;
     let mut start = span.start;
     let mut end = span.end;
 
     if bytes.starts_with(b"{") {
         start += 1;
     } else {
-        error = error.or_else(|| {
-            Some(ParseError::Expected(
-                "{".into(),
-                Span::new(start, start + 1),
-            ))
-        });
+        working_set.error(ParseError::Expected(
+            "{".into(),
+            Span::new(start, start + 1),
+        ));
+        bytes = working_set.get_span_contents(span);
     }
 
     if bytes.ends_with(b"}") {
         end -= 1;
     } else {
-        error = error.or_else(|| Some(ParseError::Unclosed("}".into(), Span::new(end, end))));
+        working_set.error(ParseError::Unclosed("}".into(), Span::new(end, end)));
     }
 
     let inner_span = Span::new(start, end);
     let source = working_set.get_span_contents(inner_span);
 
     let (tokens, err) = lex(source, start, &[b'\n', b'\r', b','], &[b':'], true);
-    error = error.or(err);
+    if let Some(err) = err {
+        working_set.error(err);
+    }
 
     let mut output = vec![];
     let mut idx = 0;
@@ -236,8 +206,7 @@ pub fn parse_record_pattern(
             // If this is a variable, treat it as both the name of the field and the pattern
             let field = String::from_utf8_lossy(&bytes[1..]).to_string();
 
-            let (pattern, err) = parse_variable_pattern(working_set, tokens[idx].span);
-            error = error.or(err);
+            let pattern = parse_variable_pattern(working_set, tokens[idx].span);
 
             (field, pattern)
         } else {
@@ -245,22 +214,17 @@ pub fn parse_record_pattern(
 
             idx += 1;
             if idx == tokens.len() {
-                return (
-                    garbage(span),
-                    Some(ParseError::Expected("record".into(), span)),
-                );
+                working_set.error(ParseError::Expected("record".into(), span));
+                return garbage(span);
             }
             let colon = working_set.get_span_contents(tokens[idx].span);
             idx += 1;
             if idx == tokens.len() || colon != b":" {
                 //FIXME: need better error
-                return (
-                    garbage(span),
-                    Some(ParseError::Expected("record".into(), span)),
-                );
+                working_set.error(ParseError::Expected("record".into(), span));
+                return garbage(span);
             }
-            let (pattern, err) = parse_pattern(working_set, tokens[idx].span);
-            error = error.or(err);
+            let pattern = parse_pattern(working_set, tokens[idx].span);
 
             (field, pattern)
         };
@@ -269,11 +233,8 @@ pub fn parse_record_pattern(
         output.push((field, pattern));
     }
 
-    (
-        MatchPattern {
-            pattern: Pattern::Record(output),
-            span,
-        },
-        error,
-    )
+    MatchPattern {
+        pattern: Pattern::Record(output),
+        span,
+    }
 }

crates/nu-parser/src/type_check.rs

@@ -1,8 +1,7 @@
-use crate::ParseError;
 use nu_protocol::{
     ast::{Bits, Boolean, Comparison, Expr, Expression, Math, Operator},
     engine::StateWorkingSet,
-    Type,
+    ParseError, Type,
 };
 
 pub fn type_compatible(lhs: &Type, rhs: &Type) -> bool {

crates/nu-parser/tests/test_lex.rs

@@ -1,5 +1,5 @@
-use nu_parser::{lex, lex_signature, ParseError, Token, TokenContents};
-use nu_protocol::Span;
+use nu_parser::{lex, lex_signature, Token, TokenContents};
+use nu_protocol::{ParseError, Span};
 
 #[test]
 fn lex_basic() {

crates/nu-parser/tests/test_parser.rs

@@ -1,11 +1,10 @@
-use nu_parser::ParseError;
 use nu_parser::*;
 use nu_protocol::ast::{Call, PathMember};
 use nu_protocol::Span;
 use nu_protocol::{
     ast::{Expr, Expression, PipelineElement},
     engine::{Command, EngineState, Stack, StateWorkingSet},
-    PipelineData, ShellError, Signature, SyntaxShape,
+    ParseError, PipelineData, ShellError, Signature, SyntaxShape,
 };
 
 #[cfg(test)]
@@ -53,7 +52,9 @@ fn test_int(
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, test, true, &[]);
+    let block = parse(&mut working_set, None, test, true, &[]);
+
+    let err = working_set.parse_errors.first();
 
     if let Some(err_pat) = expected_err {
         if let Some(parse_err) = err {
@@ -265,9 +266,9 @@ fn test_parse_any() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, test, true, &[]);
+    let block = parse(&mut working_set, None, test, true, &[]);
 
-    match (block, err) {
+    match (block, working_set.parse_errors.first()) {
         (_, Some(e)) => {
             println!("test: {test:?}, error: {e:#?}");
         }
@@ -281,9 +282,9 @@ pub fn parse_int() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"3", true, &[]);
+    let block = parse(&mut working_set, None, b"3", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -304,9 +305,9 @@ pub fn parse_int_with_underscores() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"420_69_2023", true, &[]);
+    let block = parse(&mut working_set, None, b"420_69_2023", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -334,9 +335,9 @@ pub fn parse_cell_path() {
         false,
     );
 
-    let (block, err) = parse(&mut working_set, None, b"$foo.bar.baz", true, &[]);
+    let block = parse(&mut working_set, None, b"$foo.bar.baz", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -388,12 +389,9 @@ pub fn parse_cell_path_optional() {
         false,
     );
 
-    let (block, err) = parse(&mut working_set, None, b"$foo.bar?.baz", true, &[]);
+    let block = parse(&mut working_set, None, b"$foo.bar?.baz", true, &[]);
 
-    if let Some(err) = err {
-        dbg!(err);
-        panic!();
-    }
+    assert!(working_set.parse_errors.is_empty());
 
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
@@ -439,9 +437,9 @@ pub fn parse_binary_with_hex_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0x[13]", true, &[]);
+    let block = parse(&mut working_set, None, b"0x[13]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -457,9 +455,9 @@ pub fn parse_binary_with_incomplete_hex_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0x[3]", true, &[]);
+    let block = parse(&mut working_set, None, b"0x[3]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -475,9 +473,9 @@ pub fn parse_binary_with_binary_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0b[1010 1000]", true, &[]);
+    let block = parse(&mut working_set, None, b"0b[1010 1000]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -493,9 +491,9 @@ pub fn parse_binary_with_incomplete_binary_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0b[10]", true, &[]);
+    let block = parse(&mut working_set, None, b"0b[10]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -511,9 +509,9 @@ pub fn parse_binary_with_octal_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0o[250]", true, &[]);
+    let block = parse(&mut working_set, None, b"0o[250]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -529,9 +527,9 @@ pub fn parse_binary_with_incomplete_octal_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0o[2]", true, &[]);
+    let block = parse(&mut working_set, None, b"0o[2]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -547,9 +545,9 @@ pub fn parse_binary_with_invalid_octal_format() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, b"0b[90]", true, &[]);
+    let block = parse(&mut working_set, None, b"0b[90]", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -567,9 +565,9 @@ pub fn parse_binary_with_multi_byte_char() {
 
     // found using fuzzing, Rust can panic if you slice into this string
     let contents = b"0x[\xEF\xBF\xBD]";
-    let (block, err) = parse(&mut working_set, None, contents, true, &[]);
+    let block = parse(&mut working_set, None, contents, true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
     let expressions = &block[0];
     assert_eq!(expressions.len(), 1);
@@ -588,9 +586,9 @@ pub fn parse_call() {
     let sig = Signature::build("foo").named("--jazz", SyntaxShape::Int, "jazz!!", Some('j'));
     working_set.add_decl(sig.predeclare());
 
-    let (block, err) = parse(&mut working_set, None, b"foo", true, &[]);
+    let block = parse(&mut working_set, None, b"foo", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
 
     let expressions = &block[0];
@@ -616,8 +614,11 @@ pub fn parse_call_missing_flag_arg() {
     let sig = Signature::build("foo").named("jazz", SyntaxShape::Int, "jazz!!", Some('j'));
     working_set.add_decl(sig.predeclare());
 
-    let (_, err) = parse(&mut working_set, None, b"foo --jazz", true, &[]);
-    assert!(matches!(err, Some(ParseError::MissingFlagParam(..))));
+    parse(&mut working_set, None, b"foo --jazz", true, &[]);
+    assert!(matches!(
+        working_set.parse_errors.first(),
+        Some(ParseError::MissingFlagParam(..))
+    ));
 }
 
 #[test]
@@ -628,8 +629,11 @@ pub fn parse_call_missing_short_flag_arg() {
     let sig = Signature::build("foo").named("--jazz", SyntaxShape::Int, "jazz!!", Some('j'));
     working_set.add_decl(sig.predeclare());
 
-    let (_, err) = parse(&mut working_set, None, b"foo -j", true, &[]);
-    assert!(matches!(err, Some(ParseError::MissingFlagParam(..))));
+    parse(&mut working_set, None, b"foo -j", true, &[]);
+    assert!(matches!(
+        working_set.parse_errors.first(),
+        Some(ParseError::MissingFlagParam(..))
+    ));
 }
 
 #[test]
@@ -641,9 +645,9 @@ pub fn parse_call_too_many_shortflag_args() {
         .named("--jazz", SyntaxShape::Int, "jazz!!", Some('j'))
         .named("--math", SyntaxShape::Int, "math!!", Some('m'));
     working_set.add_decl(sig.predeclare());
-    let (_, err) = parse(&mut working_set, None, b"foo -mj", true, &[]);
+    parse(&mut working_set, None, b"foo -mj", true, &[]);
     assert!(matches!(
-        err,
+        working_set.parse_errors.first(),
         Some(ParseError::ShortFlagBatchCantTakeArg(..))
     ));
 }
@@ -655,8 +659,11 @@ pub fn parse_call_unknown_shorthand() {
 
     let sig = Signature::build("foo").switch("--jazz", "jazz!!", Some('j'));
     working_set.add_decl(sig.predeclare());
-    let (_, err) = parse(&mut working_set, None, b"foo -mj", true, &[]);
-    assert!(matches!(err, Some(ParseError::UnknownFlag(..))));
+    parse(&mut working_set, None, b"foo -mj", true, &[]);
+    assert!(matches!(
+        working_set.parse_errors.first(),
+        Some(ParseError::UnknownFlag(..))
+    ));
 }
 
 #[test]
@@ -666,8 +673,11 @@ pub fn parse_call_extra_positional() {
 
     let sig = Signature::build("foo").switch("--jazz", "jazz!!", Some('j'));
     working_set.add_decl(sig.predeclare());
-    let (_, err) = parse(&mut working_set, None, b"foo -j 100", true, &[]);
-    assert!(matches!(err, Some(ParseError::ExtraPositional(..))));
+    parse(&mut working_set, None, b"foo -j 100", true, &[]);
+    assert!(matches!(
+        working_set.parse_errors.first(),
+        Some(ParseError::ExtraPositional(..))
+    ));
 }
 
 #[test]
@@ -677,8 +687,11 @@ pub fn parse_call_missing_req_positional() {
 
     let sig = Signature::build("foo").required("jazz", SyntaxShape::Int, "jazz!!");
     working_set.add_decl(sig.predeclare());
-    let (_, err) = parse(&mut working_set, None, b"foo", true, &[]);
-    assert!(matches!(err, Some(ParseError::MissingPositional(..))));
+    parse(&mut working_set, None, b"foo", true, &[]);
+    assert!(matches!(
+        working_set.parse_errors.first(),
+        Some(ParseError::MissingPositional(..))
+    ));
 }
 
 #[test]
@@ -688,17 +701,20 @@ pub fn parse_call_missing_req_flag() {
 
     let sig = Signature::build("foo").required_named("--jazz", SyntaxShape::Int, "jazz!!", None);
     working_set.add_decl(sig.predeclare());
-    let (_, err) = parse(&mut working_set, None, b"foo", true, &[]);
-    assert!(matches!(err, Some(ParseError::MissingRequiredFlag(..))));
+    parse(&mut working_set, None, b"foo", true, &[]);
+    assert!(matches!(
+        working_set.parse_errors.first(),
+        Some(ParseError::MissingRequiredFlag(..))
+    ));
 }
 
 #[test]
 fn test_nothing_comparison_eq() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
-    let (block, err) = parse(&mut working_set, None, b"2 == null", true, &[]);
+    let block = parse(&mut working_set, None, b"2 == null", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
 
     let expressions = &block[0];
@@ -719,9 +735,9 @@ fn test_nothing_comparison_eq() {
 fn test_nothing_comparison_neq() {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
-    let (block, err) = parse(&mut working_set, None, b"2 != null", true, &[]);
+    let block = parse(&mut working_set, None, b"2 != null", true, &[]);
 
-    assert!(err.is_none());
+    assert!(working_set.parse_errors.is_empty());
     assert_eq!(block.len(), 1);
 
     let expressions = &block[0];
@@ -746,9 +762,9 @@ mod string {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"\"hello nushell\"", true, &[]);
+        let block = parse(&mut working_set, None, b"\"hello nushell\"", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
         let expressions = &block[0];
         assert_eq!(expressions.len(), 1);
@@ -769,9 +785,9 @@ mod string {
             let engine_state = EngineState::new();
             let mut working_set = StateWorkingSet::new(&engine_state);
 
-            let (block, err) = parse(&mut working_set, None, b"$\"hello (39 + 3)\"", true, &[]);
+            let block = parse(&mut working_set, None, b"$\"hello (39 + 3)\"", true, &[]);
 
-            assert!(err.is_none());
+            assert!(working_set.parse_errors.is_empty());
             assert_eq!(block.len(), 1);
 
             let expressions = &block[0];
@@ -801,9 +817,9 @@ mod string {
             let engine_state = EngineState::new();
             let mut working_set = StateWorkingSet::new(&engine_state);
 
-            let (block, err) = parse(&mut working_set, None, b"$\"hello \\(39 + 3)\"", true, &[]);
+            let block = parse(&mut working_set, None, b"$\"hello \\(39 + 3)\"", true, &[]);
 
-            assert!(err.is_none());
+            assert!(working_set.parse_errors.is_empty());
 
             assert_eq!(block.len(), 1);
             let expressions = &block[0];
@@ -832,7 +848,7 @@ mod string {
             let engine_state = EngineState::new();
             let mut working_set = StateWorkingSet::new(&engine_state);
 
-            let (block, err) = parse(
+            let block = parse(
                 &mut working_set,
                 None,
                 b"$\"hello \\\\(39 + 3)\"",
@@ -840,7 +856,7 @@ mod string {
                 &[],
             );
 
-            assert!(err.is_none());
+            assert!(working_set.parse_errors.is_empty());
 
             assert_eq!(block.len(), 1);
             let expressions = &block[0];
@@ -871,7 +887,7 @@ mod string {
             let engine_state = EngineState::new();
             let mut working_set = StateWorkingSet::new(&engine_state);
 
-            let (block, err) = parse(
+            let block = parse(
                 &mut working_set,
                 None,
                 b"$\"\\(1 + 3)\\(7 - 5)\"",
@@ -879,7 +895,7 @@ mod string {
                 &[],
             );
 
-            assert!(err.is_none());
+            assert!(working_set.parse_errors.is_empty());
 
             assert_eq!(block.len(), 1);
             let expressions = &block[0];
@@ -914,7 +930,7 @@ mod string {
                 false,
             );
 
-            let (_block, err) = parse(
+            parse(
                 &mut working_set,
                 None,
                 br#"
@@ -924,7 +940,7 @@ mod string {
                 &[],
             );
 
-            assert!(err.is_none());
+            assert!(working_set.parse_errors.is_empty());
         }
 
         #[test]
@@ -939,7 +955,7 @@ mod string {
                 false,
             );
 
-            let (_block, err) = parse(
+            parse(
                 &mut working_set,
                 None,
                 br#"
@@ -949,7 +965,7 @@ mod string {
                 &[],
             );
 
-            assert!(err.is_none());
+            assert!(working_set.parse_errors.is_empty());
         }
     }
 }
@@ -963,9 +979,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"0..10", true, &[]);
+        let block = parse(&mut working_set, None, b"0..10", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -995,9 +1011,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"0..<10", true, &[]);
+        let block = parse(&mut working_set, None, b"0..<10", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1027,9 +1043,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"10..0", true, &[]);
+        let block = parse(&mut working_set, None, b"10..0", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1059,9 +1075,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"(3 - 3)..<(8 + 2)", true, &[]);
+        let block = parse(&mut working_set, None, b"(3 - 3)..<(8 + 2)", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1093,9 +1109,9 @@ mod range {
 
         working_set.add_decl(Box::new(Let));
 
-        let (block, err) = parse(&mut working_set, None, b"let a = 2; $a..10", true, &[]);
+        let block = parse(&mut working_set, None, b"let a = 2; $a..10", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 2);
 
         let expressions = &block[1];
@@ -1127,7 +1143,7 @@ mod range {
 
         working_set.add_decl(Box::new(Let));
 
-        let (block, err) = parse(
+        let block = parse(
             &mut working_set,
             None,
             b"let a = 2; $a..<($a + 10)",
@@ -1135,7 +1151,7 @@ mod range {
             &[],
         );
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 2);
 
         let expressions = &block[1];
@@ -1165,9 +1181,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"0..", true, &[]);
+        let block = parse(&mut working_set, None, b"0..", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1197,9 +1213,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"..10", true, &[]);
+        let block = parse(&mut working_set, None, b"..10", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1229,9 +1245,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"-10..-3", true, &[]);
+        let block = parse(&mut working_set, None, b"-10..-3", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1261,9 +1277,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (block, err) = parse(&mut working_set, None, b"2.0..4.0..10.0", true, &[]);
+        let block = parse(&mut working_set, None, b"2.0..4.0..10.0", true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1293,9 +1309,9 @@ mod range {
         let engine_state = EngineState::new();
         let mut working_set = StateWorkingSet::new(&engine_state);
 
-        let (_, err) = parse(&mut working_set, None, b"(0)..\"a\"", true, &[]);
+        parse(&mut working_set, None, b"(0)..\"a\"", true, &[]);
 
-        assert!(err.is_some());
+        assert!(!working_set.parse_errors.is_empty());
     }
 }
 
@@ -1616,9 +1632,9 @@ mod input_types {
         let mut working_set = StateWorkingSet::new(&engine_state);
         let input = r#"ls | to-custom | group-by name other"#;
 
-        let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+        let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1680,9 +1696,9 @@ mod input_types {
         let input =
             r#"let a = (ls | to-custom | group-by name other); let b = (1+3); $a | agg sum"#;
 
-        let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+        let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 3);
 
         let expressions = &block[2];
@@ -1711,9 +1727,9 @@ mod input_types {
         let mut working_set = StateWorkingSet::new(&engine_state);
         let input = r#"let a = (ls | to-custom | group-by name other); ($a + $a) | agg sum"#;
 
-        let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+        let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 2);
 
         let expressions = &block[1];
@@ -1743,9 +1759,9 @@ mod input_types {
         let input = r#"
         let a = (ls | to-custom | group-by name other); [1 2 3] | to-custom; [1 2 3] | to-custom"#;
 
-        let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+        let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 3);
 
         let expressions = &block[1];
@@ -1787,9 +1803,9 @@ mod input_types {
         let mut working_set = StateWorkingSet::new(&engine_state);
         let input = r#"ls | group-by name"#;
 
-        let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+        let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1832,7 +1848,7 @@ mod input_types {
         let (block, delta) = {
             let mut working_set = StateWorkingSet::new(&engine_state);
             let input = r#"ls | to-custom | group-by name other | agg ("b" | min)"#;
-            let (block, _) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+            let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
             (block, working_set.render())
         };
@@ -1893,9 +1909,9 @@ mod input_types {
         let mut working_set = StateWorkingSet::new(&engine_state);
         let input = r#"[[a b]; [1 2] [3 4]] | to-custom | with-column [ ("a" | min) ("b" | min) ] | collect"#;
 
-        let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+        let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-        assert!(err.is_none());
+        assert!(working_set.parse_errors.is_empty());
         assert_eq!(block.len(), 1);
 
         let expressions = &block[0];
@@ -1947,9 +1963,9 @@ mod input_types {
         ];
 
         for input in inputs {
-            let (block, err) = parse(&mut working_set, None, input.as_bytes(), true, &[]);
+            let block = parse(&mut working_set, None, input.as_bytes(), true, &[]);
 
-            assert!(err.is_none(), "testing: {input}");
+            assert!(working_set.parse_errors.is_empty());
             assert_eq!(block.len(), 2, "testing: {input}");
         }
     }
@@ -1960,7 +1976,7 @@ mod input_types {
         add_declarations(&mut engine_state);
 
         let mut working_set = StateWorkingSet::new(&engine_state);
-        let (_, err) = parse(
+        parse(
             &mut working_set,
             None,
             b"if false { 'a' } else { $foo }",
@@ -1968,9 +1984,10 @@ mod input_types {
             &[],
         );
 
-        let err = err.unwrap();
-
-        assert!(matches!(err, ParseError::VariableNotFound(_)));
+        assert!(matches!(
+            working_set.parse_errors.first(),
+            Some(ParseError::VariableNotFound(_))
+        ));
     }
 
     #[test]
@@ -1979,7 +1996,7 @@ mod input_types {
         add_declarations(&mut engine_state);
 
         let mut working_set = StateWorkingSet::new(&engine_state);
-        let (_, err) = parse(
+        parse(
             &mut working_set,
             None,
             b"if false { 'a' } else $foo { 'b' }",
@@ -1987,8 +2004,9 @@ mod input_types {
             &[],
         );
 
-        let err = err.unwrap();
-
-        assert!(matches!(err, ParseError::VariableNotFound(_)));
+        assert!(matches!(
+            working_set.parse_errors.first(),
+            Some(ParseError::VariableNotFound(_))
+        ));
     }
 }

crates/nu-parser/tests/test_parser_unicode_escapes.rs

@@ -14,9 +14,9 @@ pub fn do_test(test: &[u8], expected: &str, error_contains: Option<&str>) {
     let engine_state = EngineState::new();
     let mut working_set = StateWorkingSet::new(&engine_state);
 
-    let (block, err) = parse(&mut working_set, None, test, true, &[]);
+    let block = parse(&mut working_set, None, test, true, &[]);
 
-    match err {
+    match working_set.parse_errors.first() {
         None => {
             assert_eq!(block.len(), 1);
             let expressions = &block[0];

crates/nu-protocol/src/engine/engine_state.rs

@@ -2,11 +2,11 @@ use fancy_regex::Regex;
 use lru::LruCache;
 
 use super::{Command, EnvVars, OverlayFrame, ScopeFrame, Stack, Visibility, DEFAULT_OVERLAY_NAME};
-use crate::Value;
 use crate::{
     ast::Block, AliasId, BlockId, Config, DeclId, Example, Module, ModuleId, OverlayId, ShellError,
     Signature, Span, Type, VarId, Variable,
 };
+use crate::{ParseError, Value};
 use core::panic;
 use std::borrow::Borrow;
 use std::num::NonZeroUsize;
@@ -1035,6 +1035,7 @@ pub struct StateWorkingSet<'a> {
     pub currently_parsed_cwd: Option<PathBuf>,
     /// All previously parsed module files. Used to protect against circular imports.
     pub parsed_module_files: Vec<PathBuf>,
+    pub parse_errors: Vec<ParseError>,
 }
 
 /// A temporary placeholder for expression types. It is used to keep track of the input types
@@ -1218,9 +1219,14 @@ impl<'a> StateWorkingSet<'a> {
             type_scope: TypeScope::default(),
             currently_parsed_cwd: permanent_state.currently_parsed_cwd.clone(),
             parsed_module_files: vec![],
+            parse_errors: vec![],
         }
     }
 
+    pub fn error(&mut self, parse_error: ParseError) {
+        self.parse_errors.push(parse_error)
+    }
+
     pub fn num_files(&self) -> usize {
         self.delta.num_files() + self.permanent_state.num_files()
     }

crates/nu-protocol/src/lib.rs

@@ -8,6 +8,7 @@ mod exportable;
 mod id;
 mod lev_distance;
 mod module;
+mod parse_error;
 mod pipeline_data;
 #[cfg(feature = "plugin")]
 mod plugin_signature;
@@ -28,6 +29,7 @@ pub use example::*;
 pub use exportable::*;
 pub use id::*;
 pub use module::*;
+pub use parse_error::ParseError;
 pub use pipeline_data::*;
 #[cfg(feature = "plugin")]
 pub use plugin_signature::*;

crates/nu-protocol/src/parse_error.rs

@@ -1,5 +1,5 @@
+use crate::{Span, Type};
 use miette::Diagnostic;
-use nu_protocol::{Span, Type};
 use thiserror::Error;
 
 #[derive(Clone, Debug, Error, Diagnostic)]

src/command.rs

@@ -64,15 +64,15 @@ pub(crate) fn parse_commandline_args(
         let mut working_set = StateWorkingSet::new(engine_state);
         working_set.add_decl(Box::new(Nu));
 
-        let (output, err) = parse(
+        let output = parse(
             &mut working_set,
             None,
             commandline_args.as_bytes(),
             false,
             &[],
         );
-        if let Some(err) = err {
-            report_error(&working_set, &err);
+        if let Some(err) = working_set.parse_errors.first() {
+            report_error(&working_set, err);
 
             std::process::exit(1);
         }

src/config_files.rs

@@ -3,10 +3,9 @@ use log::info;
 use nu_cli::read_plugin_file;
 use nu_cli::{eval_config_contents, eval_source};
 use nu_command::util::report_error;
-use nu_parser::ParseError;
 use nu_path::canonicalize_with;
 use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{PipelineData, Spanned};
+use nu_protocol::{ParseError, PipelineData, Spanned};
 use nu_utils::{get_default_config, get_default_env};
 use std::fs::File;
 use std::io::Write;

src/ide.rs

@@ -22,7 +22,7 @@ fn find_id(
     location: &Value,
 ) -> Option<(Id, usize, Span)> {
     let offset = working_set.next_span_start();
-    let (block, _) = parse(working_set, Some(file_path), file, false, &[]);
+    let block = parse(working_set, Some(file_path), file, false, &[]);
 
     let flattened = flatten_block(working_set, &block);
 
@@ -78,9 +78,9 @@ pub fn check(engine_state: &mut EngineState, file_path: &String) {
 
     if let Ok(contents) = file {
         let offset = working_set.next_span_start();
-        let (block, err) = parse(&mut working_set, Some(file_path), &contents, false, &[]);
+        let block = parse(&mut working_set, Some(file_path), &contents, false, &[]);
 
-        if let Some(err) = err {
+        for err in &working_set.parse_errors {
             let mut span = err.span();
             span.start -= offset;
             span.end -= offset;

src/run.rs

@@ -62,21 +62,21 @@ fn load_standard_library(
         working_set.add_file(name.clone(), content);
         let end = working_set.next_span_start();
 
-        let (_, module, comments, parse_error) = parse_module_block(
+        let (_, module, comments) = parse_module_block(
             &mut working_set,
             Span::new(start, end),
             name.as_bytes(),
             &[],
         );
 
-        if let Some(err) = parse_error {
-            report_error(&working_set, &err);
+        if let Some(err) = working_set.parse_errors.first() {
+            report_error(&working_set, err);
         }
 
-        let (_, parse_error) = parse(&mut working_set, Some(&name), content, true, &[]);
+        parse(&mut working_set, Some(&name), content, true, &[]);
 
-        if let Some(err) = parse_error {
-            report_error(&working_set, &err);
+        if let Some(err) = working_set.parse_errors.first() {
+            report_error(&working_set, err);
         }
 
         // TODO: change this when #8505 is merged

src/test_bins.rs

@@ -224,7 +224,7 @@ pub fn nu_repl() {
         // Eval the REPL line
         let (block, delta) = {
             let mut working_set = StateWorkingSet::new(&engine_state);
-            let (block, err) = parse(
+            let block = parse(
                 &mut working_set,
                 Some(&format!("line{i}")),
                 line.as_bytes(),
@@ -232,8 +232,8 @@ pub fn nu_repl() {
                 &[],
             );
 
-            if let Some(err) = err {
-                outcome_err(&engine_state, &err);
+            if let Some(err) = working_set.parse_errors.first() {
+                outcome_err(&engine_state, err);
             }
             (block, working_set.render())
         };