diff options
| -rw-r--r-- | doc/api/util.md | 6 | ||||
| -rw-r--r-- | lib/internal/util/inspect.js | 39 | ||||
| -rw-r--r-- | test/parallel/test-util-format.js | 22 |
3 files changed, 55 insertions, 12 deletions
diff --git a/doc/api/util.md b/doc/api/util.md index e0b30e9a97..301089fd47 100644 --- a/doc/api/util.md +++ b/doc/api/util.md @@ -221,9 +221,9 @@ specifiers. Each specifier is replaced with the converted value from the corresponding argument. Supported specifiers are: * `%s` - `String` will be used to convert all values except `BigInt`, `Object` - and `-0`. `BigInt` values will be represented with an `n` and Objects are - inspected using `util.inspect()` with options - `{ depth: 0, colors: false, compact: 3 }`. + and `-0`. `BigInt` values will be represented with an `n` and Objects that + have no user defined `toString` function are inspected using `util.inspect()` + with options `{ depth: 0, colors: false, compact: 3 }`. * `%d` - `Number` will be used to convert all values except `BigInt` and `Symbol`. * `%i` - `parseInt(value, 10)` is used for all values except `BigInt` and diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js index 07757f3fe0..e46a18633c 100644 --- a/lib/internal/util/inspect.js +++ b/lib/internal/util/inspect.js @@ -93,6 +93,10 @@ const { NativeModule } = require('internal/bootstrap/loaders'); let hexSlice; +const builtInObjects = new Set( + Object.getOwnPropertyNames(global).filter((e) => /^([A-Z][a-z]+)+$/.test(e)) +); + const inspectDefaultOptions = Object.seal({ showHidden: false, depth: 2, @@ -1541,16 +1545,33 @@ function formatWithOptions(inspectOptions, ...args) { switch (nextChar) { case 115: // 's' const tempArg = args[++a]; - if (typeof tempArg !== 'string' && - typeof tempArg !== 'function') { - tempStr = inspect(tempArg, { - ...inspectOptions, - compact: 3, - colors: false, - depth: 0 - }); + if (typeof tempArg === 'number') { + tempStr = formatNumber(stylizeNoColor, tempArg); + // eslint-disable-next-line valid-typeof + } else if (typeof tempArg === 'bigint') { + tempStr = `${tempArg}n`; } else { - tempStr = String(tempArg); + let constr; + if (typeof tempArg !== 'object' || + tempArg === null || + typeof tempArg.toString === 'function' && + // A direct own property. + (hasOwnProperty(tempArg, 'toString') || + // A direct own property on the constructor prototype in + // case the constructor is not an built-in object. + (constr = tempArg.constructor) && + !builtInObjects.has(constr.name) && + constr.prototype && + hasOwnProperty(constr.prototype, 'toString'))) { + tempStr = String(tempArg); + } else { + tempStr = inspect(tempArg, { + ...inspectOptions, + compact: 3, + colors: false, + depth: 0 + }); + } } break; case 106: // 'j' diff --git a/test/parallel/test-util-format.js b/test/parallel/test-util-format.js index fa0f66ecfc..5b012dd64d 100644 --- a/test/parallel/test-util-format.js +++ b/test/parallel/test-util-format.js @@ -138,8 +138,30 @@ assert.strictEqual(util.format('%s', 42n), '42n'); assert.strictEqual(util.format('%s', Symbol('foo')), 'Symbol(foo)'); assert.strictEqual(util.format('%s', true), 'true'); assert.strictEqual(util.format('%s', { a: [1, 2, 3] }), '{ a: [Array] }'); +assert.strictEqual(util.format('%s', { toString() { return 'Foo'; } }), 'Foo'); +assert.strictEqual(util.format('%s', { toString: 5 }), '{ toString: 5 }'); assert.strictEqual(util.format('%s', () => 5), '() => 5'); +// String format specifier including `toString` properties on the prototype. +{ + class Foo { toString() { return 'Bar'; } } + assert.strictEqual(util.format('%s', new Foo()), 'Bar'); + assert.strictEqual( + util.format('%s', Object.setPrototypeOf(new Foo(), null)), + '[Foo: null prototype] {}' + ); + global.Foo = Foo; + assert.strictEqual(util.format('%s', new Foo()), 'Bar'); + delete global.Foo; + class Bar { abc = true; } + assert.strictEqual(util.format('%s', new Bar()), 'Bar { abc: true }'); + class Foobar extends Array { aaa = true; } + assert.strictEqual( + util.format('%s', new Foobar(5)), + 'Foobar [ <5 empty items>, aaa: true ]' + ); +} + // JSON format specifier assert.strictEqual(util.format('%j'), '%j'); assert.strictEqual(util.format('%j', 42), '42'); |