Improve error message if if is missing the else (#1252)

src/compile_error.rs

@@ -117,12 +117,23 @@ impl Display for CompileError<'_> {
       DuplicateVariable { variable } => {
         write!(f, "Variable `{}` has multiple definitions", variable)?;
       }
-      ExpectedKeyword { expected, found } => write!(
+      ExpectedKeyword { expected, found } => {
+        if found.kind == TokenKind::Identifier {
+          write!(
             f,
             "Expected keyword {} but found identifier `{}`",
             List::or_ticked(expected),
-        found
+            found.lexeme()
-      )?,
+          )?;
+        } else {
+          write!(
+            f,
+            "Expected keyword {} but found `{}`",
+            List::or_ticked(expected),
+            found.kind
+          )?;
+        }
+      }
       ExtraLeadingWhitespace => {
         write!(f, "Recipe line has extra leading whitespace")?;
       }

src/compile_error_kind.rs

@@ -42,7 +42,7 @@ pub(crate) enum CompileErrorKind<'src> {
   },
   ExpectedKeyword {
     expected: Vec<Keyword>,
-    found: &'src str,
+    found: Token<'src>,
   },
   ExtraLeadingWhitespace,
   FunctionArgumentCountMismatch {

src/parser.rs

@@ -33,7 +33,7 @@ pub(crate) struct Parser<'tokens, 'src> {
   /// Current expected tokens
   expected: BTreeSet<TokenKind>,
   /// Current recursion depth
-  depth: u8,
+  depth: usize,
 }
 
 impl<'tokens, 'src> Parser<'tokens, 'src> {
@@ -157,13 +157,12 @@ impl<'tokens, 'src> Parser<'tokens, 'src> {
   }
 
   fn expect_keyword(&mut self, expected: Keyword) -> CompileResult<'src, ()> {
-    let identifier = self.expect(Identifier)?;
+    let found = self.advance()?;
-    let found = identifier.lexeme();
 
-    if expected == found {
+    if found.kind == Identifier && expected == found.lexeme() {
       Ok(())
     } else {
-      Err(identifier.error(CompileErrorKind::ExpectedKeyword {
+      Err(found.error(CompileErrorKind::ExpectedKeyword {
         expected: vec![expected],
         found,
       }))
@@ -394,7 +393,7 @@ impl<'tokens, 'src> Parser<'tokens, 'src> {
 
   /// Parse an expression, e.g. `1 + 2`
   fn parse_expression(&mut self) -> CompileResult<'src, Expression<'src>> {
-    if self.depth == if cfg!(windows) { 64 } else { 255 } {
+    if self.depth == if cfg!(windows) { 48 } else { 256 } {
       return Err(CompileError {
         token: self.next()?,
         kind: CompileErrorKind::ParsingRecursionDepthExceeded,
@@ -422,6 +421,7 @@ impl<'tokens, 'src> Parser<'tokens, 'src> {
     };
 
     self.depth -= 1;
+
     Ok(expression)
   }
 
@@ -735,7 +735,7 @@ impl<'tokens, 'src> Parser<'tokens, 'src> {
     } else {
       return Err(identifier.error(CompileErrorKind::ExpectedKeyword {
         expected: vec![Keyword::True, Keyword::False],
-        found: identifier.lexeme(),
+        found: identifier,
       }));
     };
 

tests/assignment.rs

@@ -0,0 +1,31 @@
+use super::*;
+
+test! {
+  name: set_export_parse_error,
+  justfile: "
+  set export := fals
+  ",
+  stdout: "",
+  stderr: "
+    error: Expected keyword `true` or `false` but found identifier `fals`
+      |
+    1 | set export := fals
+      |               ^^^^
+  ",
+  status: EXIT_FAILURE,
+}
+
+test! {
+  name: set_export_parse_error_EOL,
+  justfile: "
+  set export := fals
+  ",
+  stdout: "",
+  stderr: "
+    error: Expected keyword `true` or `false` but found `end of line`
+      |
+    1 | set export := 
+      |               ^
+  ",
+  status: EXIT_FAILURE,
+}

tests/conditional.rs

@@ -168,3 +168,33 @@ test! {
   stdout: "b\n",
   stderr: "echo b\n",
 }
+
+test! {
+  name: missing_else,
+  justfile: "
+  TEST := if path_exists('/bin/bash') == 'true' {'yes'}
+  ",
+  stdout: "",
+  stderr: "
+    error: Expected keyword `else` but found `end of line`
+      |
+    1 | TEST := if path_exists('/bin/bash') == 'true' {'yes'}
+      |                                                      ^
+  ",
+  status: EXIT_FAILURE,
+}
+
+test! {
+  name: incorrect_else_identifier,
+  justfile: "
+  TEST := if path_exists('/bin/bash') == 'true' {'yes'} els {'no'}
+  ",
+  stdout: "",
+  stderr: "
+    error: Expected keyword `else` but found identifier `els`
+      |
+    1 | TEST := if path_exists('/bin/bash') == 'true' {'yes'} els {'no'}
+      |                                                       ^^^
+  ",
+  status: EXIT_FAILURE,
+}