fix(parser): parse for (using of = ...) as using declaration

crates/oxc_parser/src/js/statement.rs

@@ -411,11 +411,23 @@ impl<'a> ParserImpl<'a> {
         }
 
         // [+Using] using [no LineTerminator here] ForBinding[?Yield, ?Await, ~Pattern]
-        if self.at(Kind::Using) && {
-            let token = self.lexer.peek_token();
-            let kind = token.kind();
-            !token.is_on_new_line() && kind != Kind::Of && kind.is_binding_identifier()
-        } {
+        if self.at(Kind::Using)
+            && self.lookahead(|p| {
+                p.bump_any(); // bump `using`
+                let token = p.cur_token();
+                if token.is_on_new_line() {
+                    return false;
+                }
+                let kind = token.kind();
+                // `for (using of` is only a using declaration if followed by `=`, `;`, or `:`
+                // to distinguish from `for (using of collection)` which is a for-of loop
+                if kind == Kind::Of {
+                    p.bump_any(); // bump `of`
+                    return matches!(p.cur_kind(), Kind::Eq | Kind::Semicolon | Kind::Colon);
+                }
+                kind.is_binding_identifier()
+            })
+        {
             return self.parse_using_declaration_for_statement(
                 span,
                 parenthesis_opening_span,

tasks/coverage/snapshots/parser_babel.snap

@@ -1,11 +1,13 @@
 commit: fc58af40
 
 parser_babel Summary:
-AST Parsed     : 2222/2234 (99.46%)
-Positive Passed: 2205/2234 (98.70%)
-Negative Passed: 1649/1697 (97.17%)
+AST Parsed     : 2224/2234 (99.55%)
+Positive Passed: 2207/2234 (98.79%)
+Negative Passed: 1648/1697 (97.11%)
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2022/private-in/invalid-private-followed-by-in-2/input.js
 
+Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/invalid-for-using-of-no-initializer/input.js
+
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/estree/class-private-property/typescript-invalid-abstract/input.ts
 
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/arrow-function/arrow-like-in-conditional-2/input.ts
@@ -294,16 +296,6 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026
    ·     ╰── Opened here
    ╰────
 
-Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/valid-for-using-declaration-binding-of/input.js
-
-  × Unexpected token
-   ╭─[babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/valid-for-using-declaration-binding-of/input.js:2:17]
- 1 │ {
- 2 │   for (using of = reader();;);
-   ·                 ─
- 3 │ }
-   ╰────
-
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/valid-module-block-top-level-using-binding/input.js
 
   × Expected a semicolon or an implicit semicolon after a statement, but found none
@@ -522,16 +514,6 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
  6 │ }
    ╰────
 
-Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/explicit-resource-management/valid-for-using-declaration-binding-of/input.js
-
-  × Unexpected token
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/explicit-resource-management/valid-for-using-declaration-binding-of/input.js:2:16]
- 1 │ {
- 2 │   for (using of: Reader = reader();;);
-   ·                ─
- 3 │ }
-   ╰────
-
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/function/declare-pattern-parameters/input.ts
 
   × TS(1016): A required parameter cannot follow an optional parameter.
@@ -9278,12 +9260,6 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
    ·               ──
    ╰────
 
-  × Unexpected token
-   ╭─[babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/invalid-for-using-of-no-initializer/input.js:1:14]
- 1 │ for (using of;of.isValid;);
-   ·              ─
-   ╰────
-
   × Lexical declaration cannot appear in a single-statement context
    ╭─[babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/invalid-in-single-statement-context/input.js:2:13]
  1 │ {

tasks/coverage/snapshots/parser_test262.snap

@@ -1,8 +1,8 @@
 commit: 6f55d0c2
 
 parser_test262 Summary:
-AST Parsed     : 46555/46563 (99.98%)
-Positive Passed: 46555/46563 (99.98%)
+AST Parsed     : 46556/46563 (99.98%)
+Positive Passed: 46556/46563 (99.98%)
 Negative Passed: 4581/4581 (100.00%)
 Expect to Parse: tasks/coverage/test262/test/annexB/language/expressions/assignmenttargettype/callexpression-as-for-in-lhs.js
 
@@ -74,15 +74,6 @@ Expect to Parse: tasks/coverage/test262/test/annexB/language/expressions/assignm
  21 │ });
     ╰────
 
-Expect to Parse: tasks/coverage/test262/test/language/statements/using/syntax/using-for-statement.js
-
-  × Unexpected token
-    ╭─[test262/test/language/statements/using/syntax/using-for-statement.js:14:15]
- 13 │ // handled similar to `for (let of = null;;)`:
- 14 │ for (using of = null;;) break;
-    ·               ─
-    ╰────
-
 
   × '0'-prefixed octal literals and octal escape sequences are deprecated
     ╭─[test262/test/annexB/language/expressions/template-literal/legacy-octal-escape-sequence-strict.js:19:4]

tasks/coverage/snapshots/parser_typescript.snap

@@ -3,7 +3,7 @@ commit: f5ccf434
 parser_typescript Summary:
 AST Parsed     : 9844/9845 (99.99%)
 Positive Passed: 9836/9845 (99.91%)
-Negative Passed: 1496/2549 (58.69%)
+Negative Passed: 1495/2549 (58.65%)
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/compiler/FunctionDeclaration3.ts
 
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/compiler/FunctionDeclaration4.ts
@@ -1960,6 +1960,8 @@ Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statement
 
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/awaitUsingDeclarationsInForOf.4.ts
 
+Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/usingDeclarationsInForOf.4.ts
+
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/for-inStatements/for-inStatementsArrayErrors.ts
 
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/for-inStatements/for-inStatementsDestructuring.ts
@@ -24820,13 +24822,6 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/statements/Va
  2 │ }
    ╰────
 
-  × Unexpected token
-   ╭─[typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/usingDeclarationsInForOf.4.ts:1:15]
- 1 │ for (using of = null;;) break;
-   ·               ─
- 2 │ for (using of: null = null;;) break;
-   ╰────
-
   × Illegal break statement
    ╭─[typescript/tests/cases/conformance/statements/breakStatements/invalidDoWhileBreakStatements.ts:4:1]
  3 │ // naked break not allowed

tasks/coverage/snapshots/semantic_babel.snap

@@ -2,7 +2,7 @@ commit: fc58af40
 
 semantic_babel Summary:
 AST Parsed     : 2234/2234 (100.00%)
-Positive Passed: 1938/2234 (86.75%)
+Positive Passed: 1939/2234 (86.79%)
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/annex-b/enabled/valid-assignment-target-type/input.js
 Cannot assign to this expression
 
@@ -206,9 +206,6 @@ semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/
 Keywords cannot contain escape characters
 Expected `)` but found `of`
 
-semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/valid-for-using-declaration-binding-of/input.js
-Unexpected token
-
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/valid-module-block-top-level-using-binding/input.js
 Expected a semicolon or an implicit semicolon after a statement, but found none
 
@@ -706,7 +703,9 @@ after transform: SymbolId(0): SymbolFlags(RegularEnum)
 rebuilt        : SymbolId(0): SymbolFlags(FunctionScopedVariable)
 
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/explicit-resource-management/valid-for-using-declaration-binding-of/input.js
-Unexpected token
+Unresolved references mismatch:
+after transform: ["Reader", "reader"]
+rebuilt        : ["reader"]
 
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/export/declare/input.ts
 Bindings mismatch:

tasks/coverage/snapshots/semantic_test262.snap

@@ -2,7 +2,7 @@ commit: 6f55d0c2
 
 semantic_test262 Summary:
 AST Parsed     : 46563/46563 (100.00%)
-Positive Passed: 44919/46563 (96.47%)
+Positive Passed: 44920/46563 (96.47%)
 semantic Error: tasks/coverage/test262/test/annexB/language/expressions/assignmenttargettype/callexpression-as-for-in-lhs.js
 Cannot assign to this expression
 
@@ -14655,9 +14655,6 @@ Reference symbol mismatch for "x":
 after transform: SymbolId(1) "x"
 rebuilt        : SymbolId(1) "x"
 
-semantic Error: tasks/coverage/test262/test/language/statements/using/syntax/using-for-statement.js
-Unexpected token
-
 semantic Error: tasks/coverage/test262/test/language/statements/using/throws-if-initializer-not-object.js
 Bindings mismatch:
 after transform: ScopeId(1): ["_usingCtx", "x"]