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Diffstat (limited to 'test/language/expressions/coalesce/follows-null.js')
-rw-r--r-- | test/language/expressions/coalesce/follows-null.js | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/test/language/expressions/coalesce/follows-null.js b/test/language/expressions/coalesce/follows-null.js new file mode 100644 index 000000000..64068a5a5 --- /dev/null +++ b/test/language/expressions/coalesce/follows-null.js @@ -0,0 +1,49 @@ +// Copyright (C) 2019 Leo Balter. All rights reserved. +// This code is governed by the BSD license found in the LICENSE file. + +/*--- +description: > + If the CoalesceExpressionHead is null, follow return the right-side eval. +esid: sec-conditional-operator +info: | + ConditionalExpression : + ShortCircuitExpression + ShortCircuitExpression ? AssignmentExpression : AssignmentExpression + + ShortCircuitExpression : + LogicalORExpression + CoalesceExpression + + CoalesceExpression : + CoalesceExpressionHead ?? BitwiseORExpression + + CoalesceExpressionHead : + CoalesceExpression + BitwiseORExpression + + Runtime Semantics: Evaluation + + CoalesceExpression:CoalesceExpressionHead??BitwiseORExpression + + 1. Let lref be the result of evaluating CoalesceExpressionHead. + 2. Let lval be ? GetValue(lref). + 3. If lval is undefined or null, + a. Let rref be the result of evaluating BitwiseORExpression. + b. Return ? GetValue(rref). + 4. Otherwise, return lval. +features: [coalesce-expression] +---*/ + +var x; + +x = null ?? 42; +assert.sameValue(x, 42, 'null ?? 42'); + +x = null ?? undefined; +assert.sameValue(x, undefined, 'null ?? undefined'); + +x = null ?? null; +assert.sameValue(x, null, 'null ?? null'); + +x = null ?? false; +assert.sameValue(x, false, 'null ?? false'); |