Fix comment issue and shadowing issue (#501)

crates/nu-parser/src/lex.rs

@@ -276,25 +276,18 @@ pub fn lex(
             let mut start = curr_offset;
 
             while let Some(input) = input.get(curr_offset) {
-                curr_offset += 1;
                 if *input == b'\n' || *input == b'\r' {
                     if !skip_comment {
                         output.push(Token::new(
                             TokenContents::Comment,
-                            Span::new(start, curr_offset - 1),
-                        ));
-
-                        // Adding an end of line token after a comment
-                        // This helps during lite_parser to avoid losing a command
-                        // in a statement
-                        output.push(Token::new(
-                            TokenContents::Eol,
-                            Span::new(curr_offset - 1, curr_offset),
+                            Span::new(start, curr_offset),
                         ));
                     }
                     start = curr_offset;
 
                     break;
+                } else {
+                    curr_offset += 1;
                 }
             }
             if start != curr_offset && !skip_comment {

crates/nu-parser/src/parse_keywords.rs

@@ -13,7 +13,8 @@ use crate::{
     lex, lite_parse,
     parser::{
         check_call, check_name, garbage, garbage_statement, parse, parse_block_expression,
-        parse_import_pattern, parse_internal_call, parse_signature, parse_string, trim_quotes,
+        parse_import_pattern, parse_internal_call, parse_multispan_value, parse_signature,
+        parse_string, parse_var_with_opt_type, trim_quotes,
     },
     ParseError,
 };
@@ -956,28 +957,68 @@ pub fn parse_let(
         }
 
         if let Some(decl_id) = working_set.find_decl(b"let") {
-            let (call, call_span, err) =
-                parse_internal_call(working_set, spans[0], &spans[1..], decl_id);
+            if spans.len() >= 4 {
+                // This is a bit of by-hand parsing to get around the issue where we want to parse in the reverse order
+                // so that the var-id created by the variable isn't visible in the expression that init it
+                for span in spans.iter().enumerate() {
+                    let item = working_set.get_span_contents(*span.1);
+                    if item == b"=" && spans.len() > (span.0 + 1) {
+                        let mut error = None;
 
-            // Update the variable to the known type if we can.
-            if err.is_none() {
-                let var_id = call.positional[0]
-                    .as_var()
-                    .expect("internal error: expected variable");
-                let rhs_type = call.positional[1].ty.clone();
+                        let mut idx = span.0;
+                        let (rvalue, err) = parse_multispan_value(
+                            working_set,
+                            spans,
+                            &mut idx,
+                            &SyntaxShape::Keyword(b"=".to_vec(), Box::new(SyntaxShape::Expression)),
+                        );
+                        error = error.or(err);
 
-                if var_id != CONFIG_VARIABLE_ID {
-                    working_set.set_variable_type(var_id, rhs_type);
+                        let mut idx = 0;
+                        let (lvalue, err) =
+                            parse_var_with_opt_type(working_set, &spans[1..(span.0)], &mut idx);
+                        error = error.or(err);
+
+                        let var_id = lvalue.as_var();
+
+                        let rhs_type = rvalue.ty.clone();
+
+                        if let Some(var_id) = var_id {
+                            if var_id != CONFIG_VARIABLE_ID {
+                                working_set.set_variable_type(var_id, rhs_type);
+                            }
+                        }
+
+                        let call = Box::new(Call {
+                            decl_id,
+                            head: spans[0],
+                            positional: vec![lvalue, rvalue],
+                            named: vec![],
+                        });
+
+                        return (
+                            Statement::Pipeline(Pipeline::from_vec(vec![Expression {
+                                expr: Expr::Call(call),
+                                span: nu_protocol::span(spans),
+                                ty: Type::Unknown,
+                                custom_completion: None,
+                            }])),
+                            error,
+                        );
+                    }
                 }
             }
+            let (call, _, err) = parse_internal_call(working_set, spans[0], &spans[1..], decl_id);
 
             return (
-                Statement::Pipeline(Pipeline::from_vec(vec![Expression {
-                    expr: Expr::Call(call),
-                    span: call_span,
-                    ty: Type::Unknown,
-                    custom_completion: None,
-                }])),
+                Statement::Pipeline(Pipeline {
+                    expressions: vec![Expression {
+                        expr: Expr::Call(call),
+                        span: nu_protocol::span(spans),
+                        ty: Type::Unknown,
+                        custom_completion: None,
+                    }],
+                }),
                 err,
             );
         }

crates/nu-parser/src/parser.rs

@@ -388,7 +388,7 @@ fn calculate_end_span(
     }
 }
 
-fn parse_multispan_value(
+pub fn parse_multispan_value(
     working_set: &mut StateWorkingSet,
     spans: &[Span],
     spans_idx: &mut usize,

crates/nu-protocol/src/shell_error.rs

@@ -91,7 +91,7 @@ pub enum ShellError {
     #[diagnostic(code(nu::shell::nushell_failed), url(docsrs))]
     NushellFailed(String),
 
-    #[error("Variable not found!!!")]
+    #[error("Variable not found")]
     #[diagnostic(code(nu::shell::variable_not_found), url(docsrs))]
     VariableNotFoundAtRuntime(#[label = "variable not found"] Span),
 

src/tests.rs

@@ -1249,3 +1249,20 @@ fn command_drop_column_1() -> TestResult {
 fn chained_operator_typecheck() -> TestResult {
     run_test("1 != 2 && 3 != 4 && 5 != 6", "true")
 }
+
+#[test]
+fn proper_shadow() -> TestResult {
+    run_test("let x = 10; let x = $x + 9; $x", "19")
+}
+
+#[test]
+fn comment_multiline() -> TestResult {
+    run_test(
+        r#"def foo [] {
+        let x = 1 + 2 # comment
+        let y = 3 + 4 # another comment
+        $x + $y
+    }; foo"#,
+        "10",
+    )
+}