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assert: fix TypeError on deepStrictEqual with null Map key or Set member
deepStrictEqual() and util.isDeepStrictEqual() threw "Cannot read properties of null (reading 'constructor')" instead of comparing when a Map key or Set member was null/undefined (or another primitive) and lined up against object-only keys/members in the other collection with an equal count. The primitive/null handling was gated behind an optimization that is skipped when the counts match, letting such keys reach objectComparisonStart, which dereferences `.constructor`. Resolve primitive and null keys/members directly in every case. Signed-off-by: semx <7532921+semx@users.noreply.github.com> PR-URL: #64449 Reviewed-By: Jordan Harband <ljharb@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
1 parent 7cb3631 commit 6b28d88

2 files changed

Lines changed: 24 additions & 7 deletions

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‎lib/internal/util/comparisons.js‎

Lines changed: 9 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -699,16 +699,18 @@ function setObjectEquiv(array, a, b, mode, memo) {
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const comparator = mode !== kLoose ? objectComparisonStart : innerDeepEqual;
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const extraChecks = mode === kLoose || array.length !== a.size;
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for (const val1 of a) {
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if (extraChecks) {
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if (typeof val1 === 'object') {
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if (b.has(val1)) {
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continue;
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}
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} else if (b.has(val1)) {
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// Primitive and null members can only match by identity, and must never
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// reach objectComparisonStart (which throws on `val.constructor` for
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// null/undefined). Resolve them directly for every such member.
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if (typeof val1 !== 'object' || val1 === null) {
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if (b.has(val1)) {
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continue;
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} else if (mode !== kLoose) {
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}
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if (mode !== kLoose) {
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return false;
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}
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} else if (extraChecks && b.has(val1)) {
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continue;
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}
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let innerStart = start;

‎test/parallel/test-assert-deep.js‎

Lines changed: 15 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -278,6 +278,10 @@ test('es6 Maps and Sets', () => {
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assertDeepAndStrictEqual(new Set([[1, 2], [3, 4]]), new Set([[3, 4], [1, 2]]));
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assertNotDeepOrStrict(new Set([{ a: 0 }]), new Set([{ a: 1 }]));
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assertNotDeepOrStrict(new Set([Symbol()]), new Set([Symbol()]));
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// A null/primitive member lined up against object-only members in the other
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// set must report inequality, not throw on `member.constructor`.
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assertNotDeepOrStrict(new Set([null, {}, {}]), new Set([{}, {}, {}]));
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assertNotDeepOrStrict(new Set([undefined, {}, {}]), new Set([{}, {}, {}]));
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{
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const a = [ 1, 2 ];
@@ -298,6 +302,17 @@ test('es6 Maps and Sets', () => {
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new Map([[[1], 1], [{}, 2]]),
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new Map([[[1], 2], [{}, 1]])
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);
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// A null/primitive key that lines up with object-only keys in the other map
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// must report inequality, not throw on `key.constructor`. Refs: object keys
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// of `b` equal in count to `a.size` used to skip the primitive-key handling.
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assertNotDeepOrStrict(
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new Map([[null, 1], [{}, 2]]),
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new Map([[{}, 9], [{}, 9]])
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);
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assertNotDeepOrStrict(
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new Map([[undefined, 1], [{}, 2]]),
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new Map([[{}, 9], [{}, 9]])
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);
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assertNotDeepOrStrict(new Set([1]), [1]);
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assertNotDeepOrStrict(new Set(), []);

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