fix(compiler): produce accurate span for typeof and void expressions

crisbeto · kirjs · commit 63b1cdcf70e6 · 2026-01-07T14:04:09.000-05:00
Fixes that the `typeof` and `void` expressions were starting their spans from the expression start, rather than the keyword. Fixes #66174. (cherry picked from commit 3a56c13)
diff --git a/packages/compiler/src/expression_parser/parser.ts b/packages/compiler/src/expression_parser/parser.ts
@@ -1059,14 +1059,14 @@ class _ParseAST {
           return new PrefixNot(this.span(start), this.sourceSpan(start), result);
       }
     } else if (this.next.isKeywordTypeof()) {
-      this.advance();
       const start = this.inputIndex;
-      let result = this.parsePrefix();
+      this.advance();
+      const result = this.parsePrefix();
       return new TypeofExpression(this.span(start), this.sourceSpan(start), result);
     } else if (this.next.isKeywordVoid()) {
-      this.advance();
       const start = this.inputIndex;
-      let result = this.parsePrefix();
+      this.advance();
+      const result = this.parsePrefix();
       return new VoidExpression(this.span(start), this.sourceSpan(start), result);
     }
     return this.parseCallChain();
diff --git a/packages/compiler/test/expression_parser/parser_spec.ts b/packages/compiler/test/expression_parser/parser_spec.ts
@@ -719,6 +719,36 @@ describe('parser', () => {
       }
     });
 
+    it('should produce correct span for typeof expression', () => {
+      const ast = parseAction('foo = typeof bar');
+
+      expect(unparseWithSpan(ast)).toEqual([
+        ['foo = typeof bar', 'foo = typeof bar'],
+        ['foo', 'foo'],
+        ['foo', '[nameSpan] foo'],
+        ['', ''],
+        ['typeof bar', 'typeof bar'],
+        ['bar', 'bar'],
+        ['bar', '[nameSpan] bar'],
+        ['', ' '],
+      ]);
+    });
+
+    it('should produce correct span for void expression', () => {
+      const ast = parseAction('foo = void bar');
+
+      expect(unparseWithSpan(ast)).toEqual([
+        ['foo = void bar', 'foo = void bar'],
+        ['foo', 'foo'],
+        ['foo', '[nameSpan] foo'],
+        ['', ''],
+        ['void bar', 'void bar'],
+        ['bar', 'bar'],
+        ['bar', '[nameSpan] bar'],
+        ['', ' '],
+      ]);
+    });
+
     it('should record span for a regex without flags', () => {
       const ast = parseBinding('/^http:\\/\\/foo\\.bar/');
       expect(unparseWithSpan(ast)).toContain([
