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console: timeEnd() doesn't throw an error if no matching label - #5901

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ghaiklor:fix/3514
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console: timeEnd() doesn't throw an error if no matching label#5901
ghaiklor wants to merge 1 commit into
nodejs:masterfrom
ghaiklor:fix/3514

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@ghaiklor

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Pull Request check-list

  • Does make -j8 test (UNIX) or vcbuild test nosign (Windows) pass with
    this change (including linting)?
  • Is the commit message formatted according to [CONTRIBUTING.md][0]?
  • If this change fixes a bug (or a performance problem), is a regression
    test (or a benchmark) included?
  • Is a documentation update included (if this change modifies
    existing APIs, or introduces new ones)?

Affected core subsystem(s)

console

Description of change

Based on #3514 discussion, I've removed throw an error in timeEnd() method, if there is no matching label.

Comment threadlib/console.js Outdated

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Please revert these style changes.

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@cjihrig What style guides do you using? Should I revert all the style changes or only this one?

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We have an ESLint setup. But, in general, you should change the bare minimum in your PRs. Otherwise, it makes tools like git blame harder to use.

@ghaiklor

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@cjihrig done

@mscdexmscdex added the console Issues and PRs related to the console subsystem. label Mar 25, 2016
Comment threadtest/parallel/test-console.js Outdated

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This is unnecessary.

@ghaiklor

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@cjihrig got it, so we can ignore non-existing label.

Comment threadlib/console.js Outdated

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Can you just replace the old throw with return;. It just needs to be a one line change.

@cjihrig

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I think so (see #3514 (comment)). What you had before was wrong. It would print something but it had the incorrect times.

Comment threadtest/parallel/test-console.js Outdated

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I didn't mean to delete the whole test. Just the one line that I commented on was unnecessary.

@ghaiklor

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@cjihrig here is my code:

varconsole=require('console');console.time('test');console.timeEnd('no such label');console.timeEnd('test');

Prints only for test label:

./node test.js
test: 0.652ms

The following code:

varconsole=require('console');console.timeEnd('no such label');

prints nothing.

Comment threadlib/console.js Outdated

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Please remove this newly added line.

@cjihrig

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LGTM with one comment.

@ghaiklor

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@cjihrig I see now. I must change only lines where it actually needs. Updated.

@cjihrigcjihrig added the semver-major PRs that contain breaking changes and should be released in the next major version. label Mar 25, 2016
@cjihrig

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@jasnell

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LGTM

@thefourtheye

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We are doing this so that we would be on par with browsers? It feels like what we are doing is correct. If there is a typo in the name or if the usage is wrong we explicitly throw and let the user know what is wrong.

@jasnell

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How about a compromise? Don't throw but emit a warning using process.emitWarning.

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In case of wrong label you get nothing in the console. That way you will know that you forgot to close console.time(). Looks as expected behaviour for me.

@jasnell

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@thefourtheye ... do you still object to this or ...?

@thefourtheye

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Yes, I am still not convinced that this change is better.

To think of it, emitting a warning, as you suggested, would be the right fit here. This is not a serious error, I agree, but there should be some feedback to the user.

Comment threadlib/console.js Outdated

@jasnelljasnellApr 19, 2016

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@ghaiklor ... would it be possible for you to add a ...

process.emitWarning(`No such label: ${label}`);

...before returning here?

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Should we include console.timeEnd somewhere in the message?

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Wouldn't hurt... No such label '${label}' for console.timeEnd() perhaps? Keep in mind, also, that the warning includes a stack trace.

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Ah, then the message is just fine.

@ghaiklor

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@jasnell@thefourtheye yeah, I will update branch in few hours.

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Warning doesn't include a stack trace. So I updated message with @jasnell approach.

> console.timeEnd('no label');> (node:51305) Warning: No such label 'no label'forconsole.timeEnd()

@jasnell

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@ghaiklor. It does, it's just suppressed in the default output. If you use the --trace-warnings flag it will print the stack trace. And if you watch for warnings using process.on('warning', function(warn) { /** ... **/ });, the warn object will have a stack property that returns the stack trace.

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one additional suggestion: in the test case, you can add a check to make sure the warning is issued appropriately... something like...

process.on('warning',common.mustCall((warning)=>{assert(/Nosuchlabel'nolabel'forconsole.timeEnd\(\)/.test(warning.message));}));

@jasnell

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LGTM with a suggestion.

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I've added check for warning event in the test case.

@thefourtheye

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LGTM

Comment threadtest/parallel/test-console.js Outdated

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just use process.once('warning', onWarning) above and this isn't necessary.

@jasnell

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couple more nits after adding the warning check

Comment threadtest/parallel/test-console.js Outdated

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Does this pass linting?

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It shouldn't. We added a rule where parens are explicitly required I though

@cjihrig

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Yea, still LGTM once the comments are addressed.

@ghaiklor

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@cjihrig updated and fixed conflicts with master branch.

@cjihrig

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It would probably be simpler to use assert.strictEqual() instead of a regular expression in your test, but I don't think it needs to hold this us. Could you squash your changes down to a single commit?

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@cjihrig yes, I can, but I'm not sure if I can push them with force flag. As I understand, I need to do:

git rebase -i master

Squash all commits in one and then

git push --force origin fix/3514

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It's fine to force push your own branch. No one else is using it.

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@cjihrig done

Comment threadtest/parallel/test-console.js Outdated

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this could likely be rewritten and simplified to just:

process.once('warning',common.mustCall((warning)=>{assert(/nosuchlabel/.test(warning.message);});

There's likely very little need to test the entire warning message. You just want to verify that the warning is being issued.

@jasnell

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Just one last nit while I was looking it back over :-) Looking good!

When timeEnd() provided with label that doesn't exists
it emits warning in the console, so developer get know about it.
@ghaiklor

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@jasnell done.

BTW, why do I need squash commits by myself if it can be done when merging into master (after rebase)?

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@ghaiklor ... while it's possible for the person landing the PR to squash everything, it's often easier for those of us who do the landing to have the author of the PR squash them down (typically because it saves time). I personally don't mind squashing commits when I land things.

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New CI: https://ci.nodejs.org/job/node-test-pull-request/2359/
LGTM if CI is green

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@jasnell I see, thanks for explanation 😃
CI is green, my first contribution ^^

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Awesome! Thank you for the contribution and for the patience! @cjihrig ... does this LGTY?

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:shipit: (yes, LGTM)

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Awesome. Given that this is a semver-major, let's give time for one more round of last call comments from @nodejs/ctc. If there are no objections by Monday I'll get this landed.

@jasnelljasnell added this to the 6.0.0 milestone Apr 22, 2016
jasnell pushed a commit that referenced this pull request Apr 25, 2016
When timeEnd() provided with label that doesn't exists
it emits warning in the console, so developer get know about it.
PR-URL: #5901
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
@jasnell

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Landed in 1c84579

@jasnelljasnell closed this Apr 25, 2016
joelostrowski pushed a commit to joelostrowski/node that referenced this pull request Apr 25, 2016
When timeEnd() provided with label that doesn't exists
it emits warning in the console, so developer get know about it.
PR-URL: nodejs#5901
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
@ghaiklor
ghaiklor deleted the fix/3514 branch April 25, 2016 17:37
jasnell pushed a commit that referenced this pull request Apr 26, 2016
When timeEnd() provided with label that doesn't exists
it emits warning in the console, so developer get know about it.
PR-URL: #5901
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
antonPiPx pushed a commit to antonPiPx/node that referenced this pull request Aug 7, 2025
# Console
<!--introduced_in=v0.10.13-->
> Stability: 2 - Stable
<!-- source_link=lib/console.js -->
The `node:console` module provides a simple debugging console that is similar to
the JavaScript console mechanism provided by web browsers.
The module exports two specific components:
* A `Console` class with methods such as `console.log()`, `console.error()`, and
`console.warn()` that can be used to write to any Node.js stream.
* A global `console` instance configured to write to [`process.stdout`][] and
[`process.stderr`][]. The global `console` can be used without calling
`require('node:console')`.
_**Warning**_: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. Programs that desire to depend
on the synchronous / asynchronous behavior of the console functions should
first figure out the nature of console's backing stream. This is because the
stream is dependent on the underlying platform and standard stream
configuration of the current process. See the [note on process I/O][] for
more information.
Example using the global `console`:
```js
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
// Error: Whoops, something bad happened
// at [eval]:5:15
// at Script.runInThisContext (node:vm:132:18)
// at Object.runInThisContext (node:vm:309:38)
// at node:internal/process/execution:77:19
// at [eval]-wrapper:6:22
// at evalScript (node:internal/process/execution:76:60)
// at node:internal/main/eval_string:23:3
const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
```
Example using the `Console` class:
```js
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);
myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err
const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
```
## Class: `Console`
<!-- YAML
changes:
- version: v8.0.0
pr-url: nodejs#9744
description: Errors that occur while writing to the underlying streams
will now be ignored by default.
-->
<!--type=class-->
The `Console` class can be used to create a simple logger with configurable
output streams and can be accessed using either `require('node:console').Console`
or `console.Console` (or their destructured counterparts):
```mjs
import { Console } from 'node:console';
```
```cjs
const { Console } = require('node:console');
```
```js
const { Console } = console;
```
### `new Console(stdout[, stderr][, ignoreErrors])`
### `new Console(options)`
<!-- YAML
changes:
- version:
- v14.2.0
- v12.17.0
pr-url: nodejs#32964
description: The `groupIndentation` option was introduced.
- version: v11.7.0
pr-url: nodejs#24978
description: The `inspectOptions` option is introduced.
- version: v10.0.0
pr-url: nodejs#19372
description: The `Console` constructor now supports an `options` argument,
and the `colorMode` option was introduced.
- version: v8.0.0
pr-url: nodejs#9744
description: The `ignoreErrors` option was introduced.
-->
* `options` {Object}
* `stdout` {stream.Writable}
* `stderr` {stream.Writable}
* `ignoreErrors` {boolean} Ignore errors when writing to the underlying
streams. **Default:** `true`.
* `colorMode` {boolean|string} Set color support for this `Console` instance.
Setting to `true` enables coloring while inspecting values. Setting to
`false` disables coloring while inspecting values. Setting to
`'auto'` makes color support depend on the value of the `isTTY` property
and the value returned by `getColorDepth()` on the respective stream. This
option can not be used, if `inspectOptions.colors` is set as well.
**Default:** `'auto'`.
* `inspectOptions` {Object} Specifies options that are passed along to
[`util.inspect()`][].
* `groupIndentation` {number} Set group indentation.
**Default:** `2`.
Creates a new `Console` with one or two writable stream instances. `stdout` is a
writable stream to print log or info output. `stderr` is used for warning or
error output. If `stderr` is not provided, `stdout` is used for `stderr`.
```mjs
import { createWriteStream } from 'node:fs';
import { Console } from 'node:console';
// Alternatively
// const { Console } = console;
const output = createWriteStream('./stdout.log');
const errorOutput = createWriteStream('./stderr.log');
// Custom simple logger
const logger = new Console({ stdout: output, stderr: errorOutput });
// use it like console
const count = 5;
logger.log('count: %d', count);
// In stdout.log: count 5
```
```cjs
const fs = require('node:fs');
const { Console } = require('node:console');
// Alternatively
// const { Console } = console;
const output = fs.createWriteStream('./stdout.log');
const errorOutput = fs.createWriteStream('./stderr.log');
// Custom simple logger
const logger = new Console({ stdout: output, stderr: errorOutput });
// use it like console
const count = 5;
logger.log('count: %d', count);
// In stdout.log: count 5
```
The global `console` is a special `Console` whose output is sent to
[`process.stdout`][] and [`process.stderr`][]. It is equivalent to calling:
```js
new Console({ stdout: process.stdout, stderr: process.stderr });
```
### `console.assert(value[, ...message])`
<!-- YAML
added: v0.1.101
changes:
- version: v10.0.0
pr-url: nodejs#17706
description: The implementation is now spec compliant and does not throw
anymore.
-->
* `value` {any} The value tested for being truthy.
* `...message` {any} All arguments besides `value` are used as error message.
`console.assert()` writes a message if `value` is [falsy][] or omitted. It only
writes a message and does not otherwise affect execution. The output always
starts with `"Assertion failed"`. If provided, `message` is formatted using
[`util.format()`][].
If `value` is [truthy][], nothing happens.
```js
console.assert(true, 'does nothing');
console.assert(false, 'Whoops %s work', 'didn\'t');
// Assertion failed: Whoops didn't work
console.assert();
// Assertion failed
```
### `console.clear()`
<!-- YAML
added: v8.3.0
-->
When `stdout` is a TTY, calling `console.clear()` will attempt to clear the
TTY. When `stdout` is not a TTY, this method does nothing.
The specific operation of `console.clear()` can vary across operating systems
and terminal types. For most Linux operating systems, `console.clear()`
operates similarly to the `clear` shell command. On Windows, `console.clear()`
will clear only the output in the current terminal viewport for the Node.js
binary.
### `console.count([label])`
<!-- YAML
added: v8.3.0
-->
* `label` {string} The display label for the counter. **Default:** `'default'`.
Maintains an internal counter specific to `label` and outputs to `stdout` the
number of times `console.count()` has been called with the given `label`.
<!-- eslint-skip -->
```js
> console.count()
default: 1
undefined
> console.count('default')
default: 2
undefined
> console.count('abc')
abc: 1
undefined
> console.count('xyz')
xyz: 1
undefined
> console.count('abc')
abc: 2
undefined
> console.count()
default: 3
undefined
>
```
### `console.countReset([label])`
<!-- YAML
added: v8.3.0
-->
* `label` {string} The display label for the counter. **Default:** `'default'`.
Resets the internal counter specific to `label`.
<!-- eslint-skip -->
```js
> console.count('abc');
abc: 1
undefined
> console.countReset('abc');
undefined
> console.count('abc');
abc: 1
undefined
>
```
### `console.debug(data[, ...args])`
<!-- YAML
added: v8.0.0
changes:
- version: v8.10.0
pr-url: nodejs#17033
description: "`console.debug` is now an alias for `console.log`."
-->
* `data` {any}
* `...args` {any}
The `console.debug()` function is an alias for [`console.log()`][].
### `console.dir(obj[, options])`
<!-- YAML
added: v0.1.101
-->
* `obj` {any}
* `options` {Object}
* `showHidden` {boolean} If `true` then the object's non-enumerable and symbol
properties will be shown too. **Default:** `false`.
* `depth` {number} Tells [`util.inspect()`][] how many times to recurse while
formatting the object. This is useful for inspecting large complicated
objects. To make it recurse indefinitely, pass `null`. **Default:** `2`.
* `colors` {boolean} If `true`, then the output will be styled with ANSI color
codes. Colors are customizable;
see [customizing `util.inspect()` colors][]. **Default:** `false`.
Uses [`util.inspect()`][] on `obj` and prints the resulting string to `stdout`.
This function bypasses any custom `inspect()` function defined on `obj`.
### `console.dirxml(...data)`
<!-- YAML
added: v8.0.0
changes:
- version: v9.3.0
pr-url: nodejs#17152
description: "`console.dirxml` now calls `console.log` for its arguments."
-->
* `...data` {any}
This method calls `console.log()` passing it the arguments received.
This method does not produce any XML formatting.
### `console.error([data][, ...args])`
<!-- YAML
added: v0.1.100
-->
* `data` {any}
* `...args` {any}
Prints to `stderr` with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3) (the arguments are all passed to
[`util.format()`][]).
```js
const code = 5;
console.error('error #%d', code);
// Prints: error nodejs#5, to stderr
console.error('error', code);
// Prints: error 5, to stderr
```
If formatting elements (e.g. `%d`) are not found in the first string then
[`util.inspect()`][] is called on each argument and the resulting string
values are concatenated. See [`util.format()`][] for more information.
### `console.group([...label])`
<!-- YAML
added: v8.5.0
-->
* `...label` {any}
Increases indentation of subsequent lines by spaces for `groupIndentation`
length.
If one or more `label`s are provided, those are printed first without the
additional indentation.
### `console.groupCollapsed()`
<!-- YAML
added: v8.5.0
-->
An alias for [`console.group()`][].
### `console.groupEnd()`
<!-- YAML
added: v8.5.0
-->
Decreases indentation of subsequent lines by spaces for `groupIndentation`
length.
### `console.info([data][, ...args])`
<!-- YAML
added: v0.1.100
-->
* `data` {any}
* `...args` {any}
The `console.info()` function is an alias for [`console.log()`][].
### `console.log([data][, ...args])`
<!-- YAML
added: v0.1.100
-->
* `data` {any}
* `...args` {any}
Prints to `stdout` with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3) (the arguments are all passed to
[`util.format()`][]).
```js
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
```
See [`util.format()`][] for more information.
### `console.table(tabularData[, properties])`
<!-- YAML
added: v10.0.0
-->
* `tabularData` {any}
* `properties` {string\[]} Alternate properties for constructing the table.
Try to construct a table with the columns of the properties of `tabularData`
(or use `properties`) and rows of `tabularData` and log it. Falls back to just
logging the argument if it can't be parsed as tabular.
```js
// These can't be parsed as tabular data
console.table(Symbol());
// Symbol()
console.table(undefined);
// undefined
console.table([{ a: 1, b: 'Y' }, { a: 'Z', b: 2 }]);
// ┌─────────┬─────┬─────┐
// │ (index) │ a │ b │
// ├─────────┼─────┼─────┤
// │ 0 │ 1 │ 'Y' │
// │ 1 │ 'Z' │ 2 │
// └─────────┴─────┴─────┘
console.table([{ a: 1, b: 'Y' }, { a: 'Z', b: 2 }], ['a']);
// ┌─────────┬─────┐
// │ (index) │ a │
// ├─────────┼─────┤
// │ 0 │ 1 │
// │ 1 │ 'Z' │
// └─────────┴─────┘
```
### `console.time([label])`
<!-- YAML
added: v0.1.104
-->
* `label` {string} **Default:** `'default'`
Starts a timer that can be used to compute the duration of an operation. Timers
are identified by a unique `label`. Use the same `label` when calling
[`console.timeEnd()`][] to stop the timer and output the elapsed time in
suitable time units to `stdout`. For example, if the elapsed
time is 3869ms, `console.timeEnd()` displays "3.869s".
### `console.timeEnd([label])`
<!-- YAML
added: v0.1.104
changes:
- version: v13.0.0
pr-url: nodejs#29251
description: The elapsed time is displayed with a suitable time unit.
- version: v6.0.0
pr-url: nodejs#5901
description: This method no longer supports multiple calls that don't map
to individual `console.time()` calls; see below for details.
-->
* `label` {string} **Default:** `'default'`
Stops a timer that was previously started by calling [`console.time()`][] and
prints the result to `stdout`:
```js
console.time('bunch-of-stuff');
// Do a bunch of stuff.
console.timeEnd('bunch-of-stuff');
// Prints: bunch-of-stuff: 225.438ms
```
### `console.timeLog([label][, ...data])`
<!-- YAML
added: v10.7.0
-->
* `label` {string} **Default:** `'default'`
* `...data` {any}
For a timer that was previously started by calling [`console.time()`][], prints
the elapsed time and other `data` arguments to `stdout`:
```js
console.time('process');
const value = expensiveProcess1(); // Returns 42
console.timeLog('process', value);
// Prints "process: 365.227ms 42".
doExpensiveProcess2(value);
console.timeEnd('process');
```
### `console.trace([message][, ...args])`
<!-- YAML
added: v0.1.104
-->
* `message` {any}
* `...args` {any}
Prints to `stderr` the string `'Trace: '`, followed by the [`util.format()`][]
formatted message and stack trace to the current position in the code.
```js
console.trace('Show me');
// Prints: (stack trace will vary based on where trace is called)
// Trace: Show me
// at repl:2:9
// at REPLServer.defaultEval (repl.js:248:27)
// at bound (domain.js:287:14)
// at REPLServer.runBound [as eval] (domain.js:300:12)
// at REPLServer.<anonymous> (repl.js:412:12)
// at emitOne (events.js:82:20)
// at REPLServer.emit (events.js:169:7)
// at REPLServer.Interface._onLine (readline.js:210:10)
// at REPLServer.Interface._line (readline.js:549:8)
// at REPLServer.Interface._ttyWrite (readline.js:826:14)
```
### `console.warn([data][, ...args])`
<!-- YAML
added: v0.1.100
-->
* `data` {any}
* `...args` {any}
The `console.warn()` function is an alias for [`console.error()`][].
## Inspector only methods
The following methods are exposed by the V8 engine in the general API but do
not display anything unless used in conjunction with the [inspector][]
(`--inspect` flag).
### `console.profile([label])`
<!-- YAML
added: v8.0.0
-->
* `label` {string}
This method does not display anything unless used in the inspector. The
`console.profile()` method starts a JavaScript CPU profile with an optional
label until [`console.profileEnd()`][] is called. The profile is then added to
the **Profile** panel of the inspector.
```js
console.profile('MyLabel');
// Some code
console.profileEnd('MyLabel');
// Adds the profile 'MyLabel' to the Profiles panel of the inspector.
```
### `console.profileEnd([label])`
<!-- YAML
added: v8.0.0
-->
* `label` {string}
This method does not display anything unless used in the inspector. Stops the
current JavaScript CPU profiling session if one has been started and prints
the report to the **Profiles** panel of the inspector. See
[`console.profile()`][] for an example.
If this method is called without a label, the most recently started profile is
stopped.
### `console.timeStamp([label])`
<!-- YAML
added: v8.0.0
-->
* `label` {string}
This method does not display anything unless used in the inspector. The
`console.timeStamp()` method adds an event with the label `'label'` to the
**Timeline** panel of the inspector.
[`console.error()`]: #consoleerrordata-args
[`console.group()`]: #consolegrouplabel
[`console.log()`]: #consolelogdata-args
[`console.profile()`]: #consoleprofilelabel
[`console.profileEnd()`]: #consoleprofileendlabel
[`console.time()`]: #consoletimelabel
[`console.timeEnd()`]: #consoletimeendlabel
[`process.stderr`]: process.md#processstderr
[`process.stdout`]: process.md#processstdout
[`util.format()`]: util.md#utilformatformat-args
[`util.inspect()`]: util.md#utilinspectobject-options
[customizing `util.inspect()` colors]: util.md#customizing-utilinspect-colors
[falsy]: https://developer.mozilla.org/en-US/docs/Glossary/Falsy
[inspector]: debugger.md
[note on process I/O]: process.md#a-note-on-process-io
[truthy]: https://developer.mozilla.org/en-US/docs/Glossary/Truthy
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@ghaiklor@cjihrig@jasnell@thefourtheye@evanlucas@mscdex