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util: fix formatting of objects with built-in Symbol.toPrimitive #57832

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Merged
nodejs-github-bot merged 6 commits into from
Apr 17, 2025
Merged

util: fix formatting of objects with built-in Symbol.toPrimitive #57832

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74e49ba
util: fix formatting of objects with built-in Symbol.toPrimitive
islandryu Apr 11, 2025
9941038
add symbol test
islandryu Apr 11, 2025
140a6f2
handle the case toPrimitive is defined in prototype
islandryu Apr 12, 2025
476a700
add test
islandryu Apr 12, 2025
5b0ac9b
add comment
islandryu Apr 12, 2025
412347c
fix to not call unnecessary hasOwnProperty
islandryu Apr 14, 2025
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handle the case toPrimitive is defined in prototype
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@islandryu
islandryu committed Apr 12, 2025
commit 140a6f28cff5ceb9d75c313547425aaa3a492553
9 changes: 5 additions & 4 deletions lib/internal/util/inspect.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2160,7 +2160,7 @@ function hasBuiltInToString(value) {
}
value = proxyTarget;
}
// Count objects that have neither a `toString` function nor a `Symbol.toPrimitive` function.
// Count objects without `toString` and `Symbol.toPrimitive` function as built-in.
if (typeof value.toString !== 'function' && typeof value[SymbolToPrimitive] !== 'function') {
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return true;
}
Expand All @@ -2175,12 +2175,13 @@ function hasBuiltInToString(value) {
return false;
}

// Find the object that has the `toString` property as own property in the
// prototype chain.
// Find the object that has the `toString` property or `Symbol.toPrimitive` property
// as own property in the prototype chain.
let pointer = value;
do {
pointer = ObjectGetPrototypeOf(pointer);
} while (!ObjectPrototypeHasOwnProperty(pointer, 'toString'));
} while (!ObjectPrototypeHasOwnProperty(pointer, 'toString') &&
!ObjectPrototypeHasOwnProperty(pointer, SymbolToPrimitive));

// Check closer if the object is a built-in.
const descriptor = ObjectGetOwnPropertyDescriptor(pointer, 'constructor');
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22 changes: 22 additions & 0 deletions test/parallel/test-util-format.js
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Expand Up @@ -299,6 +299,28 @@ assert.strictEqual(util.format('%s', -Infinity), '-Infinity');
assert.strictEqual(util.format('%s', symbol), util.inspect(symbol));
}

{
function hasToStringButNoToPrimitive() {}

hasToStringButNoToPrimitive.prototype.toString = function() {
return 'hasToStringButNoToPrimitive';
};

const obj = new hasToStringButNoToPrimitive();
assert.strictEqual(util.format('%s', obj.toString()), 'hasToStringButNoToPrimitive');
}

{
function hasToPrimitiveButNoToString() {}

hasToPrimitiveButNoToString.prototype[Symbol.toPrimitive] = function() {
return 'hasToPrimitiveButNoToString';
};

const obj = new hasToPrimitiveButNoToString();
assert.strictEqual(util.format('%s', obj[Symbol.toPrimitive]()), 'hasToPrimitiveButNoToString');
}

// JSON format specifier
assert.strictEqual(util.format('%j'), '%j');
assert.strictEqual(util.format('%j', 42), '42');
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