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41 changes: 41 additions & 0 deletions doc/api/console.markdown
Original file line number Diff line number Diff line change
Expand Up @@ -109,6 +109,46 @@ console.assert(false, 'Whoops %s', 'didn\'t work');
// AssertionError: Whoops didn't work
```

*Note: the `console.assert()` method is implemented differently in Node.js
than the `console.assert()` method [available in browsers][web-api-assert].*

Specifically, in browsers, calling `console.assert()` with a falsy
assertion will cause the `message` to be printed to the console without
interrupting execution of subsequent code. In Node.js, however, a falsy
assertion will cause an `AssertionError` to be thrown.

Functionality approximating that implemented by browsers can be implemented
by extending Node.js' `console` and overriding the `console.assert()` method.

In the following example, a simple module is created that extends and overrides
the default behavior of `console` in Node.js.

```js
'use strict';

// Creates a simple extension of console with a
// new impl for assert without monkey-patching.
const myConsole = Object.setPrototypeOf({
assert(assertion, message, ...args) {
try {
console.assert(assertion, message, ...args);
} catch (err) {
console.error(err.stack);
}
}
}, console);

module.exports = myConsole;
```

This can then be used as a direct replacement for the built in console:

```js
const console = require('./myConsole');
console.assert(false, 'this message will print, but no error thrown');
console.log('this will also print');
```

### console.dir(obj[, options])

Uses [`util.inspect()`][] on `obj` and prints the resulting string to `stdout`.
Expand Down Expand Up @@ -224,3 +264,4 @@ The `console.warn()` function is an alias for [`console.error()`][].
[`util.format()`]: util.html#util_util_format_format
[`util.inspect()`]: util.html#util_util_inspect_object_options
[customizing `util.inspect()` colors]: util.html#util_customizing_util_inspect_colors
[web-api-assert]: https://developer.mozilla.org/en-US/docs/Web/API/console/assert