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-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 {