Add NU_REPL_PREV_ERROR env variable

benches/benchmarks.rs

@@ -121,7 +121,7 @@ fn bench_eval_source(
             let mut engine = engine.clone();
             let fname: &str = &fname.clone();
             let source: &[u8] = &source.clone();
-            black_box(eval_source(
+            let _ = black_box(eval_source(
                 &mut engine,
                 &mut stack,
                 source,

crates/nu-cli/src/config_files.rs

@@ -299,7 +299,8 @@ pub fn migrate_old_plugin_file(engine_state: &EngineState, storage_path: &str) -
         &old_plugin_file_path.to_string_lossy(),
         PipelineData::Empty,
         false,
-    ) != 0
+    )
+    .is_err()
     {
         return false;
     }

crates/nu-cli/src/eval_file.rs

@@ -1,4 +1,4 @@
-use crate::util::eval_source;
+use crate::util::{eval_source, ParseOrShellError};
 use log::{info, trace};
 use nu_engine::{convert_env_values, eval_block};
 use nu_parser::parse;
@@ -106,7 +106,7 @@ pub fn evaluate_file(
     engine_state.merge_delta(working_set.delta)?;
 
     // Check if the file contains a main command.
-    let exit_code = if engine_state.find_decl(b"main", &[]).is_some() {
+    let result = if engine_state.find_decl(b"main", &[]).is_some() {
         // Evaluate the file, but don't run main yet.
         let pipeline =
             match eval_block::<WithoutDebug>(engine_state, stack, &block, PipelineData::empty()) {
@@ -136,7 +136,11 @@ pub fn evaluate_file(
         eval_source(engine_state, stack, &file, file_path_str, input, true)
     };
 
-    if exit_code != 0 {
+    if let Err(err) = result {
+        let exit_code = match err {
+            ParseOrShellError::ShellError(err) => err.exit_code(),
+            ParseOrShellError::ParseError(_) => 1,
+        };
         std::process::exit(exit_code);
     }
 

crates/nu-cli/src/repl.rs

@@ -10,7 +10,7 @@ use crate::{
     nu_highlight::NoOpHighlighter,
     prompt_update,
     reedline_config::{add_menus, create_keybindings, KeybindingsMode},
-    util::eval_source,
+    util::{eval_source, ParseOrShellError},
     NuHighlighter, NuValidator, NushellPrompt,
 };
 use crossterm::cursor::SetCursorStyle;
@@ -27,6 +27,7 @@ use nu_protocol::{
     report_shell_error, HistoryConfig, HistoryFileFormat, PipelineData, ShellError, Span, Spanned,
     Value,
 };
+use nu_protocol::{record, IntoValue};
 use nu_utils::{
     filesystem::{have_permission, PermissionResult},
     perf,
@@ -101,7 +102,8 @@ pub fn evaluate_repl(
     let temp_file = temp_dir().join(format!("{}.nu", uuid::Uuid::new_v4()));
 
     if let Some(s) = prerun_command {
-        eval_source(
+        // TODO: ignore this error?
+        let _ = eval_source(
             engine_state,
             &mut unique_stack,
             s.item.as_bytes(),
@@ -156,7 +158,8 @@ pub fn evaluate_repl(
     engine_state.generate_nu_constant();
 
     if load_std_lib.is_none() && engine_state.get_config().show_banner {
-        eval_source(
+        // TODO: ignore this error?
+        let _ = eval_source(
             engine_state,
             &mut unique_stack,
             r#"use std banner; banner"#.as_bytes(),
@@ -906,7 +909,7 @@ fn do_run_cmd(
         run_shell_integration_osc2(Some(s), engine_state, stack, use_color);
     }
 
-    eval_source(
+    let result = eval_source(
         engine_state,
         stack,
         s.as_bytes(),
@@ -915,6 +918,21 @@ fn do_run_cmd(
         false,
     );
 
+    if let Err(err) = result {
+        let span = Span::unknown();
+        let err = match err {
+            ParseOrShellError::ShellError(err) => err.into_value(span),
+            ParseOrShellError::ParseError(err) => record! {
+                "msg" => Value::string(err.to_string(), span),
+                "debug" => Value::string(format!("{err:?}"), span),
+            }
+            .into_value(span),
+        };
+        stack.add_env_var("NU_REPL_PREV_ERROR".into(), err);
+    } else {
+        stack.remove_env_var(engine_state, "NU_REPL_PREV_ERROR");
+    }
+
     line_editor
 }
 

crates/nu-cli/src/util.rs

@@ -5,8 +5,8 @@ use nu_protocol::{
     cli_error::report_compile_error,
     debugger::WithoutDebug,
     engine::{EngineState, Stack, StateWorkingSet},
-    report_parse_error, report_parse_warning, report_shell_error, PipelineData, ShellError, Span,
-    Value,
+    report_parse_error, report_parse_warning, report_shell_error, ParseError, PipelineData,
+    ShellError, Span, Value,
 };
 #[cfg(windows)]
 use nu_utils::enable_vt_processing;
@@ -201,6 +201,24 @@ fn gather_env_vars(
     }
 }
 
+#[derive(Clone, Debug)]
+pub enum ParseOrShellError {
+    ParseError(ParseError),
+    ShellError(ShellError),
+}
+
+impl From<ParseError> for ParseOrShellError {
+    fn from(err: ParseError) -> Self {
+        Self::ParseError(err)
+    }
+}
+
+impl From<ShellError> for ParseOrShellError {
+    fn from(err: ShellError) -> Self {
+        Self::ShellError(err)
+    }
+}
+
 pub fn eval_source(
     engine_state: &mut EngineState,
     stack: &mut Stack,
@@ -208,20 +226,22 @@ pub fn eval_source(
     fname: &str,
     input: PipelineData,
     allow_return: bool,
-) -> i32 {
+) -> Result<(), ParseOrShellError> {
     let start_time = std::time::Instant::now();
 
-    let exit_code = match evaluate_source(engine_state, stack, source, fname, input, allow_return) {
-        Ok(failed) => {
-            let code = failed.into();
-            stack.set_last_exit_code(code, Span::unknown());
-            code
+    let result = match evaluate_source(engine_state, stack, source, fname, input, allow_return) {
+        Ok(()) => {
+            stack.set_last_exit_code(0, Span::unknown());
+            Ok(())
         }
-        Err(err) => {
+        Err(ParseOrShellError::ShellError(err)) => {
             report_shell_error(engine_state, &err);
-            let code = err.exit_code();
             stack.set_last_error(&err);
-            code
+            Err(ParseOrShellError::ShellError(err))
+        }
+        Err(ParseOrShellError::ParseError(err)) => {
+            stack.set_last_exit_code(1, Span::unknown());
+            Err(ParseOrShellError::ParseError(err))
         }
     };
 
@@ -237,7 +257,7 @@ pub fn eval_source(
         engine_state.get_config().use_ansi_coloring
     );
 
-    exit_code
+    result
 }
 
 fn evaluate_source(
@@ -247,7 +267,7 @@ fn evaluate_source(
     fname: &str,
     input: PipelineData,
     allow_return: bool,
-) -> Result<bool, ShellError> {
+) -> Result<(), ParseOrShellError> {
     let (block, delta) = {
         let mut working_set = StateWorkingSet::new(engine_state);
         let output = parse(
@@ -262,7 +282,7 @@ fn evaluate_source(
 
         if let Some(err) = working_set.parse_errors.first() {
             report_parse_error(&working_set, err);
-            return Ok(true);
+            return Err(ParseOrShellError::ParseError(err.clone()));
         }
 
         if let Some(err) = working_set.compile_errors.first() {
@@ -297,7 +317,7 @@ fn evaluate_source(
         pipeline.print(engine_state, stack, true, false)
     }?;
 
-    Ok(false)
+    Ok(())
 }
 
 #[cfg(test)]

src/config_files.rs

@@ -155,7 +155,9 @@ pub(crate) fn read_loginshell_file(engine_state: &mut EngineState, stack: &mut S
 
 pub(crate) fn read_default_env_file(engine_state: &mut EngineState, stack: &mut Stack) {
     let config_file = get_default_env();
-    eval_source(
+
+    // TODO: ignore this error?
+    let _ = eval_source(
         engine_state,
         stack,
         config_file.as_bytes(),
@@ -236,7 +238,8 @@ fn eval_default_config(
         &config_file, is_env_config
     );
     // Just use the contents of "default_config.nu" or "default_env.nu"
-    eval_source(
+    // TODO: ignore this error?
+    let _ = eval_source(
         engine_state,
         stack,
         config_file.as_bytes(),