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.

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())
         };