| // This file was procedurally generated from the following sources: |
| // - src/dstr-binding-for-await/obj-ptrn-id-init-skipped.case |
| // - src/dstr-binding-for-await/default/for-await-of-async-gen-const.template |
| /*--- |
| description: Destructuring initializer is not evaluated when value is not `undefined` (for-await-of statement) |
| esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation |
| features: [destructuring-binding, async-iteration] |
| flags: [generated, async] |
| info: | |
| IterationStatement : |
| for await ( ForDeclaration of AssignmentExpression ) Statement |
| |
| [...] |
| 2. Return ? ForIn/OfBodyEvaluation(ForDeclaration, Statement, keyResult, |
| lexicalBinding, labelSet, async). |
| |
| 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation |
| |
| [...] |
| 4. Let destructuring be IsDestructuring of lhs. |
| [...] |
| 6. Repeat |
| [...] |
| j. If destructuring is false, then |
| [...] |
| k. Else |
| i. If lhsKind is assignment, then |
| [...] |
| ii. Else if lhsKind is varBinding, then |
| [...] |
| iii. Else, |
| 1. Assert: lhsKind is lexicalBinding. |
| 2. Assert: lhs is a ForDeclaration. |
| 3. Let status be the result of performing BindingInitialization |
| for lhs passing nextValue and iterationEnv as arguments. |
| [...] |
| |
| 13.3.3.7 Runtime Semantics: KeyedBindingInitialization |
| |
| SingleNameBinding : BindingIdentifier Initializer_opt |
| |
| [...] |
| 6. If Initializer is present and v is undefined, then |
| [...] |
| [...] |
| ---*/ |
| var initCount = 0; |
| function counter() { |
| initCount += 1; |
| } |
| |
| var iterCount = 0; |
| |
| async function *fn() { |
| for await (const { w = counter(), x = counter(), y = counter(), z = counter() } of [{ w: null, x: 0, y: false, z: '' }]) { |
| assert.sameValue(w, null); |
| assert.sameValue(x, 0); |
| assert.sameValue(y, false); |
| assert.sameValue(z, ''); |
| assert.sameValue(initCount, 0); |
| |
| iterCount += 1; |
| } |
| } |
| |
| fn().next() |
| .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE) |
| .then($DONE, $DONE); |