`util.inspect()` ignores `breakLength: Infinity` when `depth: Infinity` is also set in some cases

Version

v25.1.0

Platform

- Windows: Microsoft Windows NT 10.0.26200.0 x64
- macOS: Darwin MacBook-Pro.local 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:51 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T8112 arm64
- Linux: Linux myhost 6.8.0-45-generic #45-Ubuntu SMP PREEMPT_DYNAMIC x86_64 GNU/Linux

Subsystem

util

What steps will reproduce the bug?

When util.inspect() is called with both breakLength: Infinity and depth: Infinity, the output unexpectedly contains line breaks in Node.js v25.x.

In contrast:

• Using only breakLength: Infinity (with default depth) works correctly and produces a single-line output.
• The issue appears only when depth is explicitly set to Infinity.

This behavior did not occur in Node.js v24.x, so it appears to be a regression.

A minimal reproducible example is provided below.

$ nvm use 24
Now using node v24.11.0 (npm v11.6.1)
$ node
Welcome to Node.js v24.11.0.
Type ".help" for more information.
> const util = require("node:util")
undefined
> util.inspect(util, { breakLength: Infinity })
"{ _errnoException: [Function: _errnoException], _exceptionWithHostPort: [Function: _exceptionWithHostPort], _extend: [Function: deprecated], callbackify: [Function: callbackify], debug: [Function: debuglog], debuglog: [Function: debuglog], deprecate: [Function: deprecate], format: [Function: format], styleText: [Function: styleText], formatWithOptions: [Function: formatWithOptions], getCallSites: [Function: getCallSites], getSystemErrorMap: [Function: getSystemErrorMap], getSystemErrorName: [Function: getSystemErrorName], getSystemErrorMessage: [Function: getSystemErrorMessage], inherits: [Function: inherits], inspect: [Function: inspect] { custom: Symbol(nodejs.util.inspect.custom), colors: [Object: null prototype] { reset: [Array], bold: [Array], dim: [Array], italic: [Array], underline: [Array], blink: [Array], inverse: [Array], hidden: [Array], strikethrough: [Array], doubleunderline: [Array], black: [Array], red: [Array], green: [Array], yellow: [Array], blue: [Array], magenta: [Array], cyan: [Array], white: [Array], bgBlack: [Array], bgRed: [Array], bgGreen: [Array], bgYellow: [Array], bgBlue: [Array], bgMagenta: [Array], bgCyan: [Array], bgWhite: [Array], framed: [Array], overlined: [Array], gray: [Array], redBright: [Array], greenBright: [Array], yellowBright: [Array], blueBright: [Array], magentaBright: [Array], cyanBright: [Array], whiteBright: [Array], bgGray: [Array], bgRedBright: [Array], bgGreenBright: [Array], bgYellowBright: [Array], bgBlueBright: [Array], bgMagentaBright: [Array], bgCyanBright: [Array], bgWhiteBright: [Array] }, styles: [Object: null prototype] { special: 'cyan', number: 'yellow', bigint: 'yellow', boolean: 'yellow', undefined: 'grey', null: 'bold', string: 'green', symbol: 'green', date: 'magenta', regexp: 'red', module: 'underline' }, replDefaults: [Getter/Setter] }, isArray: [Function: deprecated], isDeepStrictEqual: [Function: isDeepStrictEqual], promisify: [Function: promisify] { custom: Symbol(nodejs.util.promisify.custom) }, stripVTControlCharacters: [Function: stripVTControlCharacters], toUSVString: [Function: toUSVString], transferableAbortSignal: [Getter], transferableAbortController: [Getter], aborted: [Getter], types: { isArgumentsObject: [Function (anonymous)], isArrayBuffer: [Function (anonymous)], isAsyncFunction: [Function (anonymous)], isBigIntObject: [Function (anonymous)], isBooleanObject: [Function (anonymous)], isDataView: [Function (anonymous)], isDate: [Function (anonymous)], isExternal: [Function (anonymous)], isGeneratorFunction: [Function (anonymous)], isGeneratorObject: [Function (anonymous)], isMap: [Function (anonymous)], isMapIterator: [Function (anonymous)], isModuleNamespaceObject: [Function (anonymous)], isNativeError: [Function (anonymous)], isNumberObject: [Function (anonymous)], isPromise: [Function (anonymous)], isProxy: [Function (anonymous)], isRegExp: [Function (anonymous)], isSet: [Function (anonymous)], isSetIterator: [Function (anonymous)], isSharedArrayBuffer: [Function (anonymous)], isStringObject: [Function (anonymous)], isSymbolObject: [Function (anonymous)], isWeakMap: [Function (anonymous)], isWeakSet: [Function (anonymous)], isAnyArrayBuffer: [Function (anonymous)], isBoxedPrimitive: [Function (anonymous)], isArrayBufferView: [Function: isView], isTypedArray: [Function: isTypedArray], isUint8Array: [Function: isUint8Array], isUint8ClampedArray: [Function: isUint8ClampedArray], isUint16Array: [Function: isUint16Array], isUint32Array: [Function: isUint32Array], isInt8Array: [Function: isInt8Array], isInt16Array: [Function: isInt16Array], isInt32Array: [Function: isInt32Array], isFloat16Array: [Function: isFloat16Array], isFloat32Array: [Function: isFloat32Array], isFloat64Array: [Function: isFloat64Array], isBigInt64Array: [Function: isBigInt64Array], isBigUint64Array: [Function: isBigUint64Array], isKeyObject: [Function: value], isCryptoKey: [Function: value] }, parseEnv: [Function: parseEnv], parseArgs: [Function: parseArgs], TextDecoder: [class TextDecoder], TextEncoder: [class TextEncoder], MIMEType: [class MIMEType], MIMEParams: [class MIMEParams], diff: [Function: diff], setTraceSigInt: [Function: setTraceSigInt] }"
> util.inspect(util, { breakLength: Infinity, depth: Infinity })
"{ _errnoException: [Function: _errnoException], _exceptionWithHostPort: [Function: _exceptionWithHostPort], _extend: [Function: deprecated], callbackify: [Function: callbackify], debug: [Function: debuglog], debuglog: [Function: debuglog], deprecate: [Function: deprecate], format: [Function: format], styleText: [Function: styleText], formatWithOptions: [Function: formatWithOptions], getCallSites: [Function: getCallSites], getSystemErrorMap: [Function: getSystemErrorMap], getSystemErrorName: [Function: getSystemErrorName], getSystemErrorMessage: [Function: getSystemErrorMessage], inherits: [Function: inherits], inspect: [Function: inspect] { custom: Symbol(nodejs.util.inspect.custom), colors: [Object: null prototype] { reset: [ 0, 0 ], bold: [ 1, 22 ], dim: [ 2, 22 ], italic: [ 3, 23 ], underline: [ 4, 24 ], blink: [ 5, 25 ], inverse: [ 7, 27 ], hidden: [ 8, 28 ], strikethrough: [ 9, 29 ], doubleunderline: [ 21, 24 ], black: [ 30, 39 ], red: [ 31, 39 ], green: [ 32, 39 ], yellow: [ 33, 39 ], blue: [ 34, 39 ], magenta: [ 35, 39 ], cyan: [ 36, 39 ], white: [ 37, 39 ], bgBlack: [ 40, 49 ], bgRed: [ 41, 49 ], bgGreen: [ 42, 49 ], bgYellow: [ 43, 49 ], bgBlue: [ 44, 49 ], bgMagenta: [ 45, 49 ], bgCyan: [ 46, 49 ], bgWhite: [ 47, 49 ], framed: [ 51, 54 ], overlined: [ 53, 55 ], gray: [ 90, 39 ], redBright: [ 91, 39 ], greenBright: [ 92, 39 ], yellowBright: [ 93, 39 ], blueBright: [ 94, 39 ], magentaBright: [ 95, 39 ], cyanBright: [ 96, 39 ], whiteBright: [ 97, 39 ], bgGray: [ 100, 49 ], bgRedBright: [ 101, 49 ], bgGreenBright: [ 102, 49 ], bgYellowBright: [ 103, 49 ], bgBlueBright: [ 104, 49 ], bgMagentaBright: [ 105, 49 ], bgCyanBright: [ 106, 49 ], bgWhiteBright: [ 107, 49 ] }, styles: [Object: null prototype] { special: 'cyan', number: 'yellow', bigint: 'yellow', boolean: 'yellow', undefined: 'grey', null: 'bold', string: 'green', symbol: 'green', date: 'magenta', regexp: 'red', module: 'underline' }, replDefaults: [Getter/Setter] }, isArray: [Function: deprecated], isDeepStrictEqual: [Function: isDeepStrictEqual], promisify: [Function: promisify] { custom: Symbol(nodejs.util.promisify.custom) }, stripVTControlCharacters: [Function: stripVTControlCharacters], toUSVString: [Function: toUSVString], transferableAbortSignal: [Getter], transferableAbortController: [Getter], aborted: [Getter], types: { isArgumentsObject: [Function (anonymous)], isArrayBuffer: [Function (anonymous)], isAsyncFunction: [Function (anonymous)], isBigIntObject: [Function (anonymous)], isBooleanObject: [Function (anonymous)], isDataView: [Function (anonymous)], isDate: [Function (anonymous)], isExternal: [Function (anonymous)], isGeneratorFunction: [Function (anonymous)], isGeneratorObject: [Function (anonymous)], isMap: [Function (anonymous)], isMapIterator: [Function (anonymous)], isModuleNamespaceObject: [Function (anonymous)], isNativeError: [Function (anonymous)], isNumberObject: [Function (anonymous)], isPromise: [Function (anonymous)], isProxy: [Function (anonymous)], isRegExp: [Function (anonymous)], isSet: [Function (anonymous)], isSetIterator: [Function (anonymous)], isSharedArrayBuffer: [Function (anonymous)], isStringObject: [Function (anonymous)], isSymbolObject: [Function (anonymous)], isWeakMap: [Function (anonymous)], isWeakSet: [Function (anonymous)], isAnyArrayBuffer: [Function (anonymous)], isBoxedPrimitive: [Function (anonymous)], isArrayBufferView: [Function: isView], isTypedArray: [Function: isTypedArray], isUint8Array: [Function: isUint8Array], isUint8ClampedArray: [Function: isUint8ClampedArray], isUint16Array: [Function: isUint16Array], isUint32Array: [Function: isUint32Array], isInt8Array: [Function: isInt8Array], isInt16Array: [Function: isInt16Array], isInt32Array: [Function: isInt32Array], isFloat16Array: [Function: isFloat16Array], isFloat32Array: [Function: isFloat32Array], isFloat64Array: [Function: isFloat64Array], isBigInt64Array: [Function: isBigInt64Array], isBigUint64Array: [Function: isBigUint64Array], isKeyObject: [Function: value], isCryptoKey: [Function: value] }, parseEnv: [Function: parseEnv], parseArgs: [Function: parseArgs], TextDecoder: [class TextDecoder], TextEncoder: [class TextEncoder], MIMEType: [class MIMEType], MIMEParams: [class MIMEParams], diff: [Function: diff], setTraceSigInt: [Function: setTraceSigInt] }"
>
$ nvm use 25
Now using node v25.1.0 (npm v11.6.2)
$ node
Welcome to Node.js v25.1.0.
Type ".help" for more information.
> const util = require("node:util")
undefined
> util.inspect(util, { breakLength: Infinity })
"{ _errnoException: [Function: _errnoException], _exceptionWithHostPort: [Function: _exceptionWithHostPort], _extend: [Function: deprecated], callbackify: [Function: callbackify], debug: [Function: debuglog], debuglog: [Function: debuglog], deprecate: [Function: deprecate], format: [Function: format], styleText: [Function: styleText], formatWithOptions: [Function: formatWithOptions], getCallSites: [Function: getCallSites], getSystemErrorMap: [Function: getSystemErrorMap], getSystemErrorName: [Function: getSystemErrorName], getSystemErrorMessage: [Function: getSystemErrorMessage], inherits: [Function: inherits], inspect: [Function: inspect] { custom: Symbol(nodejs.util.inspect.custom), colors: [Object: null prototype] { reset: [Array], bold: [Array], dim: [Array], italic: [Array], underline: [Array], blink: [Array], inverse: [Array], hidden: [Array], strikethrough: [Array], doubleunderline: [Array], black: [Array], red: [Array], green: [Array], yellow: [Array], blue: [Array], magenta: [Array], cyan: [Array], white: [Array], bgBlack: [Array], bgRed: [Array], bgGreen: [Array], bgYellow: [Array], bgBlue: [Array], bgMagenta: [Array], bgCyan: [Array], bgWhite: [Array], framed: [Array], overlined: [Array], gray: [Array], redBright: [Array], greenBright: [Array], yellowBright: [Array], blueBright: [Array], magentaBright: [Array], cyanBright: [Array], whiteBright: [Array], bgGray: [Array], bgRedBright: [Array], bgGreenBright: [Array], bgYellowBright: [Array], bgBlueBright: [Array], bgMagentaBright: [Array], bgCyanBright: [Array], bgWhiteBright: [Array] }, styles: [Object: null prototype] { special: 'cyan', number: 'yellow', bigint: 'yellow', boolean: 'yellow', undefined: 'grey', null: 'bold', string: 'green', symbol: 'green', date: 'magenta', regexp: [Function], module: 'underline' }, replDefaults: [Getter/Setter] }, isArray: [Function: deprecated], isDeepStrictEqual: [Function: isDeepStrictEqual], promisify: [Function: promisify] { custom: Symbol(nodejs.util.promisify.custom) }, stripVTControlCharacters: [Function: stripVTControlCharacters], toUSVString: [Function: toUSVString], transferableAbortSignal: [Getter], transferableAbortController: [Getter], aborted: [Getter], types: { isArgumentsObject: [Function (anonymous)], isArrayBuffer: [Function (anonymous)], isAsyncFunction: [Function (anonymous)], isBigIntObject: [Function (anonymous)], isBooleanObject: [Function (anonymous)], isDataView: [Function (anonymous)], isDate: [Function (anonymous)], isExternal: [Function (anonymous)], isGeneratorFunction: [Function (anonymous)], isGeneratorObject: [Function (anonymous)], isMap: [Function (anonymous)], isMapIterator: [Function (anonymous)], isModuleNamespaceObject: [Function (anonymous)], isNativeError: [Function (anonymous)], isNumberObject: [Function (anonymous)], isPromise: [Function (anonymous)], isProxy: [Function (anonymous)], isRegExp: [Function (anonymous)], isSet: [Function (anonymous)], isSetIterator: [Function (anonymous)], isSharedArrayBuffer: [Function (anonymous)], isStringObject: [Function (anonymous)], isSymbolObject: [Function (anonymous)], isWeakMap: [Function (anonymous)], isWeakSet: [Function (anonymous)], isAnyArrayBuffer: [Function (anonymous)], isBoxedPrimitive: [Function (anonymous)], isArrayBufferView: [Function: isView], isTypedArray: [Function: isTypedArray], isUint8Array: [Function: isUint8Array], isUint8ClampedArray: [Function: isUint8ClampedArray], isUint16Array: [Function: isUint16Array], isUint32Array: [Function: isUint32Array], isInt8Array: [Function: isInt8Array], isInt16Array: [Function: isInt16Array], isInt32Array: [Function: isInt32Array], isFloat16Array: [Function: isFloat16Array], isFloat32Array: [Function: isFloat32Array], isFloat64Array: [Function: isFloat64Array], isBigInt64Array: [Function: isBigInt64Array], isBigUint64Array: [Function: isBigUint64Array], isKeyObject: [Function: value], isCryptoKey: [Function: value] }, parseEnv: [Function: parseEnv], parseArgs: [Function: parseArgs], TextDecoder: [class TextDecoder], TextEncoder: [class TextEncoder], MIMEType: [class MIMEType], MIMEParams: [class MIMEParams], diff: [Function: diff], setTraceSigInt: [Function: setTraceSigInt] }"
> util.inspect(util, { breakLength: Infinity, depth: Infinity })
'{\n' +
  '  _errnoException: [Function: _errnoException],\n' +
  '  _exceptionWithHostPort: [Function: _exceptionWithHostPort],\n' +
  '  _extend: [Function: deprecated],\n' +
  '  callbackify: [Function: callbackify],\n' +
  '  debug: [Function: debuglog],\n' +
  '  debuglog: [Function: debuglog],\n' +
  '  deprecate: [Function: deprecate],\n' +
  '  format: [Function: format],\n' +
  '  styleText: [Function: styleText],\n' +
  '  formatWithOptions: [Function: formatWithOptions],\n' +
  '  getCallSites: [Function: getCallSites],\n' +
  '  getSystemErrorMap: [Function: getSystemErrorMap],\n' +
  '  getSystemErrorName: [Function: getSystemErrorName],\n' +
  '  getSystemErrorMessage: [Function: getSystemErrorMessage],\n' +
  '  inherits: [Function: inherits],\n' +
  '  inspect: [Function: inspect] {\n' +
  '    custom: Symbol(nodejs.util.inspect.custom),\n' +
  '    colors: [Object: null prototype] { reset: [ 0, 0 ], bold: [ 1, 22 ], dim: [ 2, 22 ], italic: [ 3, 23 ], underline: [ 4, 24 ], blink: [ 5, 25 ], inverse: [ 7, 27 ], hidden: [ 8, 28 ], strikethrough: [ 9, 29 ], doubleunderline: [ 21, 24 ], black: [ 30, 39 ], red: [ 31, 39 ], green: [ 32, 39 ], yellow: [ 33, 39 ], blue: [ 34, 39 ], magenta: [ 35, 39 ], cyan: [ 36, 39 ], white: [ 37, 39 ], bgBlack: [ 40, 49 ], bgRed: [ 41, 49 ], bgGreen: [ 42, 49 ], bgYellow: [ 43, 49 ], bgBlue: [ 44, 49 ], bgMagenta: [ 45, 49 ], bgCyan: [ 46, 49 ], bgWhite: [ 47, 49 ], framed: [ 51, 54 ], overlined: [ 53, 55 ], gray: [ 90, 39 ], redBright: [ 91, 39 ], greenBright: [ 92, 39 ], yellowBright: [ 93, 39 ], blueBright: [ 94, 39 ], magentaBright: [ 95, 39 ], cyanBright: [ 96, 39 ], whiteBright: [ 97, 39 ], bgGray: [ 100, 49 ], bgRedBright: [ 101, 49 ], bgGreenBright: [ 102, 49 ], bgYellowBright: [ 103, 49 ], bgBlueBright: [ 104, 49 ], bgMagentaBright: [ 105, 49 ], bgCyanBright: [ 106, 49 ], bgWhiteBright: [ 107, 49 ] },\n' +
  "    styles: [Object: null prototype] { special: 'cyan', number: 'yellow', bigint: 'yellow', boolean: 'yellow', undefined: 'grey', null: 'bold', string: 'green', symbol: 'green', date: 'magenta', regexp: [Function: highlightRegExp] { colors: [ 'green', 'red', 'yellow', 'cyan', 'magenta' ] }, module: 'underline' },\n" +
  '    replDefaults: [Getter/Setter]\n' +
  '  },\n' +
  '  isArray: [Function: deprecated],\n' +
  '  isDeepStrictEqual: [Function: isDeepStrictEqual],\n' +
  '  promisify: [Function: promisify] { custom: Symbol(nodejs.util.promisify.custom) },\n' +
  '  stripVTControlCharacters: [Function: stripVTControlCharacters],\n' +
  '  toUSVString: [Function: toUSVString],\n' +
  '  transferableAbortSignal: [Getter],\n' +
  '  transferableAbortController: [Getter],\n' +
  '  aborted: [Getter],\n' +
  '  types: { isArgumentsObject: [Function (anonymous)], isArrayBuffer: [Function (anonymous)], isAsyncFunction: [Function (anonymous)], isBigIntObject: [Function (anonymous)], isBooleanObject: [Function (anonymous)], isDataView: [Function (anonymous)], isDate: [Function (anonymous)], isExternal: [Function (anonymous)], isGeneratorFunction: [Function (anonymous)], isGeneratorObject: [Function (anonymous)], isMap: [Function (anonymous)], isMapIterator: [Function (anonymous)], isModuleNamespaceObject: [Function (anonymous)], isNativeError: [Function (anonymous)], isNumberObject: [Function (anonymous)], isPromise: [Function (anonymous)], isProxy: [Function (anonymous)], isRegExp: [Function (anonymous)], isSet: [Function (anonymous)], isSetIterator: [Function (anonymous)], isSharedArrayBuffer: [Function (anonymous)], isStringObject: [Function (anonymous)], isSymbolObject: [Function (anonymous)], isWeakMap: [Function (anonymous)], isWeakSet: [Function (anonymous)], isAnyArrayBuffer: [Function (anonymous)], isBoxedPrimitive: [Function (anonymous)], isArrayBufferView: [Function: isView], isTypedArray: [Function: isTypedArray], isUint8Array: [Function: isUint8Array], isUint8ClampedArray: [Function: isUint8ClampedArray], isUint16Array: [Function: isUint16Array], isUint32Array: [Function: isUint32Array], isInt8Array: [Function: isInt8Array], isInt16Array: [Function: isInt16Array], isInt32Array: [Function: isInt32Array], isFloat16Array: [Function: isFloat16Array], isFloat32Array: [Function: isFloat32Array], isFloat64Array: [Function: isFloat64Array], isBigInt64Array: [Function: isBigInt64Array], isBigUint64Array: [Function: isBigUint64Array], isKeyObject: [Function: value], isCryptoKey: [Function: value] },\n' +
  '  parseEnv: [Function: parseEnv],\n' +
  '  parseArgs: [Function: parseArgs],\n' +
  '  TextDecoder: [class TextDecoder],\n' +
  '  TextEncoder: [class TextEncoder],\n' +
  '  MIMEType: [class MIMEType],\n' +
  '  MIMEParams: [class MIMEParams],\n' +
  '  diff: [Function: diff],\n' +
  '  setTraceSigInt: [Function: setTraceSigInt]\n' +
  '}'

How often does it reproduce? Is there a required condition?

Always reproducible when both breakLength and depth are set to Infinity.

What is the expected behavior? Why is that the expected behavior?

According to the Node.js documentation:

breakLength <integer>
The length at which input values are split across multiple lines.
Set to Infinity to format the input as a single line (in combination with compact set to true or any number >= 1).
Default: 80.

Therefore, when breakLength is set to Infinity, the output should always be rendered as a single line, regardless of object depth or size.

What do you see instead?

The output contains multiple lines with indentation, even though breakLength is set to Infinity.

This happens only when depth is also set to Infinity.

Additional information

No response

首先，在 Node.js v24 和 v25 上分别使用 breakLength: Infinity 和 depth: Infinity，复现最小的 util.inspect() 示例。跟踪 util.inspect() 的实现以及这些选项现有的覆盖情况；完成的标准是组合选项能够生成预期的单行输出，同时不会导致所述其他情况出现回归。