mirror of https://github.com/tc39/test262.git
44 lines
1006 B
JavaScript
44 lines
1006 B
JavaScript
// Copyright 2019 Google, LLC. All rights reserved.
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// This code is governed by the BSD license found in the LICENSE file.
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/*---
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esid: prod-OptionalExpression
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description: >
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optional chain in init/test/update of for statement
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info: |
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IterationStatement
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for (Expression; Expression; Expression) Statement
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features: [optional-chaining]
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---*/
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// OptionalExpression in test.
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let count;
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const obj = {a: true};
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for (count = 0; obj?.a; count++) {
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if (count > 0) break;
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}
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assert.sameValue(count, 1);
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// OptionalExpression in init/test/update.
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let count2 = 0;
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const obj2 = undefined;
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for (obj?.a; obj2?.a; obj?.a) { count2++; }
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assert.sameValue(count2, 0);
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for (obj?.a; undefined?.a; obj?.a) { count2++; }
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assert.sameValue(count2, 0);
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// Short-circuiting
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let touched = 0;
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const obj3 = {
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get a() {
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count++;
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return undefined; // explicit for clarity
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}
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};
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for (count = 0; true; obj3?.a?.[touched++]) {
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if (count > 0) { break; }
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}
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assert.sameValue(count, 1);
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assert.sameValue(touched, 0);
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