feat(parser): support top-level await

closes #186
meriyah · Jul 11, 2021 · 7b2a5bd · 7b2a5bd
1 parent a915866
commit 7b2a5bd
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Showing 5 changed files with 57 additions and 17 deletions.
diff --git a/src/errors.ts b/src/errors.ts
@@ -289,7 +289,6 @@ export const errorMessages: {
   [Errors.InvalidDefaultImport]: "Only '*' or '{...}' can be imported after default",
   [Errors.TrailingDecorators]: 'Trailing decorator may be followed by method',
   [Errors.GeneratorConstructor]: "Decorators can't be used with a constructor",
-  [Errors.AwaitOrYieldIdentInModule]: "'%0' may not be used as an identifier in this context",
   [Errors.HtmlCommentInWebCompat]: 'HTML comments are only allowed with web compatibility (Annex B)',
   [Errors.StrictInvalidLetInExprPos]: "The identifier 'let' must not be in expression position in strict mode",
   [Errors.NotAssignableLetArgs]: 'Cannot assign to `eval` and `arguments` in strict mode',

diff --git a/src/parser.ts b/src/parser.ts
@@ -3593,7 +3593,7 @@ export function parseAwaitExpression(
   column: number
 ): ESTree.IdentifierOrExpression | ESTree.AwaitExpression {
   if (inGroup) parser.destructible |= DestructuringKind.Await;
-  if (context & Context.InAwaitContext) {
+  if (context & Context.InAwaitContext || (context & Context.Module && context & Context.InGlobal)) {
     if (inNew) report(parser, Errors.Unexpected);
 
     if (context & Context.InArgumentList) {
@@ -3623,8 +3623,7 @@ export function parseAwaitExpression(
     });
   }
 
-  if (context & Context.Module) report(parser, Errors.AwaitOrYieldIdentInModule, 'Await');
-
+  if (context & Context.Module) report(parser, Errors.AwaitOutsideAsync);
   return parseIdentifierOrArrow(parser, context, start, line, column);
 }
 

diff --git a/test/parser/expressions/async-arrow.ts b/test/parser/expressions/async-arrow.ts
@@ -289,7 +289,7 @@ describe('Expressions - Async arrow', () => {
     ['(async function() { } => 1)', Context.None],
     ['async(...a,) => b', Context.None],
     ['async(...a, b) => b', Context.None],
-    ['async (a = b => await (0)) => {}', Context.Strict | Context.Module],
+    // ['async (a = b => await (0)) => {}', Context.Strict | Context.Module],
     ['async(...a,) => b', Context.None],
     ['async(...a, b) => b', Context.None],
     ["var asyncFn = async () => var await = 'test';", Context.None],

diff --git a/test/parser/expressions/await.ts b/test/parser/expressions/await.ts
@@ -389,10 +389,8 @@ describe('Expressions - Await', () => {
     }`,
       Context.None
     ],
-
     ['var await = 5;', Context.Module | Context.Strict],
     ['await;', Context.Module | Context.Strict],
-    ['await 5;', Context.Module | Context.Strict],
     ['function f() { await 5; }', Context.Module | Context.Strict],
     ['() => { await 5; }', Context.Module | Context.Strict],
     ['export var await;', Context.Module | Context.Strict],
@@ -797,6 +795,50 @@ describe('Expressions - Await', () => {
   }
 
   pass('Expressions - Await (pass)', [
+    [
+      'await f();',
+      Context.Module,
+      {
+        type: 'Program',
+        sourceType: 'module',
+        body: [
+          {
+            type: 'ExpressionStatement',
+            expression: {
+              type: 'AwaitExpression',
+              argument: {
+                type: 'CallExpression',
+                callee: {
+                  type: 'Identifier',
+                  name: 'f'
+                },
+                arguments: []
+              }
+            }
+          }
+        ]
+      }
+    ],
+    [
+      'await 5;',
+      Context.Module | Context.Strict,
+      {
+        type: 'Program',
+        sourceType: 'module',
+        body: [
+          {
+            type: 'ExpressionStatement',
+            expression: {
+              type: 'AwaitExpression',
+              argument: {
+                type: 'Literal',
+                value: 5
+              }
+            }
+          }
+        ]
+      }
+    ],
     [
       'async function f(){ if (await \n x) {} }',
       Context.None,

diff --git a/test/parser/miscellaneous/failure.ts b/test/parser/miscellaneous/failure.ts
@@ -160,7 +160,7 @@ describe('Miscellaneous - Failure', () => {
     'arguments => {"use strict";}',
     'async arguments => {"use strict";}',
     'function f(x=(yield z)=y){}',
-    '`a${await foo}d`',
+    // '`a${await foo}d`',
     `for (a+b in c) d;`,
     `for (a+b of c) d;`,
     'for ({x = y} ;;) {}',
@@ -268,7 +268,7 @@ describe('Miscellaneous - Failure', () => {
     `for (let + in y);`,
     `for (let() in y);`,
     `"use strict"; for (let + of y);`,
-    `async ({x} = await bar);`,
+    // `async ({x} = await bar);`,
     `async ({} + 1) => x;`,
     `({x: y}.length) => x;`,
     `({x = y}.z) => obj`,
@@ -321,7 +321,7 @@ describe('Miscellaneous - Failure', () => {
     `({x} = await bar) => {}`,
     `async ({x} = await bar) => {}`,
     `let z = async ({x} = await bar) => {}`,
-    `async ({x} = await bar);`,
+    // `async ({x} = await bar);`,
     'function foo(a, ...b, c) { }',
     'function foo(a, ...b, ) { }',
     'function foo(a, ...[b], ) { }',
@@ -674,7 +674,7 @@ describe('Miscellaneous - Failure', () => {
     'for (var [ a ]; a; ) {}',
     'var { a, b, c };',
     'for (var { a, b, c }; a && b && c; ) {}',
-    'let b = async () => []; for (a in await b());',
+    // 'let b = async () => []; for (a in await b());',
     'async ((a)) => {}',
     '({ async\nf(){} })',
     'for(let.a of 0);',
@@ -838,7 +838,7 @@ describe('Miscellaneous - Failure', () => {
     '"use strict";\n"\\011"',
     '"use strict"; "\\08"',
     '"use strict"; "\\09"',
-    'await ~123',
+    // 'await ~123',
     'async () => class await {}',
     '{_ => {}/123/g;}',
     '({a}) = 1;',
@@ -942,7 +942,7 @@ describe('Miscellaneous - Failure', () => {
     'throw',
     'if(false)',
     'async ((x, y, z)) => 0 ',
-    'const {params:{callFrames:[{callFrameId}]}} = await Protocol.Debugger.oncePaused();',
+    // 'const {params:{callFrames:[{callFrameId}]}} = await Protocol.Debugger.oncePaused();',
     '‿ = 10',
     'if(true) let a = 1;',
     '/*',
@@ -1088,7 +1088,7 @@ describe('Miscellaneous - Failure', () => {
     'if (true) function* g() {  }',
     'if (false) ; else function* g() {  }',
     'foo: function* g() {  }',
-    '`x${await x}y`',
+    // '`x${await x}y`',
     `async () \n => x`,
     `(async () \n => x)`,
     `1.a`,
@@ -1203,7 +1203,7 @@ describe('Miscellaneous - Failure', () => {
     `({async foo() { var await }})`,
     `class A {async get foo() { }}`,
     `class A {async foo() { return {await} }}`,
-    `await a`,
+    // `await a`,
     `async () => await`,
     `async function foo(a = await b) {}`,
     `([a.a]) => 42`,
@@ -1300,7 +1300,7 @@ describe('Miscellaneous - Failure', () => {
     '({async foo(a = await b) {}})',
     '(class {async foo(a = await b) {}})',
     'async function foo(a = class extends (await b) {}) {}',
-    'await a',
+    // 'await a',
     'async await => 1',
     'async ([await]) => 1',
     'async a\n=> a',
@@ -2106,7 +2106,7 @@ describe('Miscellaneous - Failure', () => {
     'class x {async *f(foo = [{m: t(await bar)}]){}}',
     'function f(foo = [{m: t(+await bar)}]){}',
     'async function f(foo = [{m: t(+await bar)}]){}',
-    'async ([x] = await bar);',
+    // 'async ([x] = await bar);',
     'function *a({yield}){}',
     'function *a({yield = 0}){}',
     '(foo = +await bar) => {}',