// Copyright (c) 2020 Ecma International. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-assignment-operators-runtime-semantics-evaluation description: Logical Nullish Assignment Operator info: | AssignmentExpression: LeftHandSideExpression ??= AssignmentExpression 1. Let lref be the result of evaluating LeftHandSideExpression. 2. Let lval be ? GetValue(lref). 3. If lval is neither undefined nor null, return lval. 4. Let rref be the result of evaluating AssignmentExpression. 5. Let rval be ? GetValue(rref). 6. Perform ? PutValue(lref, rval). 7. Return rval. features: [logical-assignment-operators] ---*/ var value = undefined; assert.sameValue(value ??= 1, 1, "(value ??= 1) === 1; where value = undefined"); value = null; assert.sameValue(value ??= 1, 1, "(value ??= 1) === 1; where value = null"); value = false; assert.sameValue(value ??= 1, false, "(value ??= 1) === false; where value = false"); value = 0; assert.sameValue(value ??= 1, 0, "(value ??= 1) === 0; where value = 0"); value = -0; assert.sameValue(value ??= 1, -0, "(value ??= 1) === -0; where value = -0"); value = NaN; assert.sameValue(value ??= 1, NaN, "(value ??= 1) === NaN; where value = NaN"); value = ""; assert.sameValue(value ??= 1, "", '(value ??= 1) === "" where value = ""'); value = true; assert.sameValue(value ??= 1, true, "(value ??= 1) === true; where value = true"); value = 2; assert.sameValue(value ??= 1, 2, "(value ??= 1) === 2; where value = 2"); value = "test"; assert.sameValue(value ??= 1, "test", '(value ??= 1) === "test"; where value = "test"'); var sym = Symbol(""); value = sym; assert.sameValue(value ??= 1, sym, "(value ??= 1) === Symbol(); where value = Symbol()"); var obj = {}; value = obj; assert.sameValue(value ??= 1, obj, "(value ??= 1) === {}; where value = {}");