Add Jest 23 docs (#6254)

* Add Jest 23 docs

* Add the files

website/versioned_docs/version-23.0/CLI.md

@@ -0,0 +1,356 @@
+---
+id: version-23.0-cli
+title: Jest CLI Options
+original_id: cli
+---
+
+The `jest` command line runner has a number of useful options. You can run
+`jest --help` to view all available options. Many of the options shown below can
+also be used together to run tests exactly the way you want. Every one of Jest's
+[Configuration](Configuration.md) options can also be specified through the CLI.
+
+Here is a brief overview:
+
+## Running from the command line
+
+Run all tests (default):
+
+```bash
+jest
+```
+
+Run only the tests that were specified with a pattern or filename:
+
+```bash
+jest my-test #or
+jest path/to/my-test.js
+```
+
+Run tests related to changed files based on hg/git (uncommitted files):
+
+```bash
+jest -o
+```
+
+Run tests related to `path/to/fileA.js` and `path/to/fileB.js`:
+
+```bash
+jest --findRelatedTests path/to/fileA.js path/to/fileB.js
+```
+
+Run tests that match this spec name (match against the name in `describe` or
+`test`, basically).
+
+```bash
+jest -t name-of-spec
+```
+
+Run watch mode:
+
+```bash
+jest --watch #runs jest -o by default
+jest --watchAll #runs all tests
+```
+
+Watch mode also enables to specify the name or path to a file to focus on a
+specific set of tests.
+
+## Using with yarn
+
+If you run Jest via `yarn test`, you can pass the command line arguments
+directly as Jest arguments.
+
+Instead of:
+
+```bash
+jest -u -t="ColorPicker"
+```
+
+you can use:
+
+```bash
+yarn test -u -t="ColorPicker"
+```
+
+## Using with npm scripts
+
+If you run Jest via `npm test`, you can still use the command line arguments by
+inserting a `--` between `npm test` and the Jest arguments.
+
+Instead of:
+
+```bash
+jest -u -t="ColorPicker"
+```
+
+you can use:
+
+```bash
+npm test -- -u -t="ColorPicker"
+```
+
+## Options
+
+_Note: CLI options take precedence over values from the
+[Configuration](Configuration.md)._
+
+<AUTOGENERATED_TABLE_OF_CONTENTS>
+
+---
+
+## Reference
+
+### `jest <regexForTestFiles>`
+
+When you run `jest` with an argument, that argument is treated as a regular
+expression to match against files in your project. It is possible to run test
+suites by providing a pattern. Only the files that the pattern matches will be
+picked up and executed. Depending on your terminal, you may need to quote this
+argument: `jest "my.*(complex)?pattern"`. On Windows, you will need to use `/`
+as a path separator or escape `\` as `\\`.
+
+### `--bail`
+
+Alias: `-b`. Exit the test suite immediately upon the first failing test suite.
+
+### `--cache`
+
+Whether to use the cache. Defaults to true. Disable the cache using
+`--no-cache`. _Note: the cache should only be disabled if you are experiencing
+caching related problems. On average, disabling the cache makes Jest at least
+two times slower._
+
+If you want to inspect the cache, use `--showConfig` and look at the
+`cacheDirectory` value. If you need to clear the cache, use `--clearCache`.
+
+### `--changedFilesWithAncestor`
+
+Runs tests related to the current changes and the changes made in the last
+commit. Behaves similarly to `--onlyChanged`.
+
+### `--changedSince`
+
+Runs tests related the changes since the provided branch. If the current branch
+has diverged from the given branch, then only changes made locally will be
+tested. Behaves similarly to `--onlyChanged`.
+
+### `--ci`
+
+When this option is provided, Jest will assume it is running in a CI
+environment. This changes the behavior when a new snapshot is encountered.
+Instead of the regular behavior of storing a new snapshot automatically, it will
+fail the test and require Jest to be run with `--updateSnapshot`.
+
+### `--clearCache`
+
+Deletes the Jest cache directory and then exits without running tests. Will
+delete `cacheDirectory` if the option is passed, or Jest's default cache
+directory. The default cache directory can be found by calling
+`jest --showConfig`. _Note: clearing the cache will reduce performance._
+
+### `--collectCoverageFrom=<glob>`
+
+A glob pattern relative to <rootDir> matching the files that coverage info needs
+to be collected from.
+
+### `--colors`
+
+Forces test results output highlighting even if stdout is not a TTY.
+
+### `--config=<path>`
+
+Alias: `-c`. The path to a Jest config file specifying how to find and execute
+tests. If no `rootDir` is set in the config, the current directory is assumed to
+be the rootDir for the project. This can also be a JSON-encoded value which Jest
+will use as configuration.
+
+### `--coverage`
+
+Indicates that test coverage information should be collected and reported in the
+output.
+
+### `--debug`
+
+Print debugging info about your Jest config.
+
+### `--detectOpenHandles`
+
+Attempt to collect and print open handles preventing Jest from exiting cleanly.
+Use this in cases where you need to use `--forceExit` in order for Jest to exit
+to potentially track down the reason. Implemented using
+[`async_hooks`](https://nodejs.org/api/async_hooks.html), so it only works in
+Node 8 and newer.
+
+### `--env=<environment>`
+
+The test environment used for all tests. This can point to any file or node
+module. Examples: `jsdom`, `node` or `path/to/my-environment.js`.
+
+### `--expand`
+
+Alias: `-e`. Use this flag to show full diffs and errors instead of a patch.
+
+### `--findRelatedTests <spaceSeparatedListOfSourceFiles>`
+
+Find and run the tests that cover a space separated list of source files that
+were passed in as arguments. Useful for pre-commit hook integration to run the
+minimal amount of tests necessary. Can be used together with `--coverage` to
+include a test coverage for the source files, no duplicate
+`--collectCoverageFrom` arguments needed.
+
+### `--forceExit`
+
+Force Jest to exit after all tests have completed running. This is useful when
+resources set up by test code cannot be adequately cleaned up. _Note: This
+feature is an escape-hatch. If Jest doesn't exit at the end of a test run, it
+means external resources are still being held on to or timers are still pending
+in your code. It is advised to tear down external resources after each test to
+make sure Jest can shut down cleanly. You can use `--detectOpenHandles` to help
+track it down._
+
+### `--help`
+
+Show the help information, similar to this page.
+
+### `--json`
+
+Prints the test results in JSON. This mode will send all other test output and
+user messages to stderr.
+
+### `--outputFile=<filename>`
+
+Write test results to a file when the `--json` option is also specified.
+
+### `--lastCommit`
+
+Run all tests affected by file changes in the last commit made. Behaves
+similarly to `--onlyChanged`.
+
+### `--listTests`
+
+Lists all tests as JSON that Jest will run given the arguments, and exits. This
+can be used together with `--findRelatedTests` to know which tests Jest will
+run.
+
+### `--logHeapUsage`
+
+Logs the heap usage after every test. Useful to debug memory leaks. Use together
+with `--runInBand` and `--expose-gc` in node.
+
+### `--maxWorkers=<num>`
+
+Alias: `-w`. Specifies the maximum number of workers the worker-pool will spawn
+for running tests. This defaults to the number of the cores available on your
+machine. It may be useful to adjust this in resource limited environments like
+CIs but the default should be adequate for most use-cases.
+
+### `--noStackTrace`
+
+Disables stack trace in test results output.
+
+### `--notify`
+
+Activates notifications for test results. Good for when you don't want your
+consciousness to be able to focus on anything except JavaScript testing.
+
+### `--onlyChanged`
+
+Alias: `-o`. Attempts to identify which tests to run based on which files have
+changed in the current repository. Only works if you're running tests in a
+git/hg repository at the moment and requires a static dependency graph (ie. no
+dynamic requires).
+
+### `--passWithNoTests`
+
+Allows the test suite to pass when no files are found.
+
+### `--projects <project1> ... <projectN>`
+
+Run tests from one or more projects.
+
+### `--runInBand`
+
+Alias: `-i`. Run all tests serially in the current process, rather than creating
+a worker pool of child processes that run tests. This can be useful for
+debugging.
+
+### `--setupTestFrameworkScriptFile=<file>`
+
+The path to a module that runs some code to configure or set up the testing
+framework before each test. Beware that files imported by the setup script will
+not be mocked during testing.
+
+### `--showConfig`
+
+Print your Jest config and then exits.
+
+### `--silent`
+
+Prevent tests from printing messages through the console.
+
+### `--testNamePattern=<regex>`
+
+Alias: `-t`. Run only tests with a name that matches the regex. For example,
+suppose you want to run only tests related to authorization which will have
+names like `"GET /api/posts with auth"`, then you can use `jest -t=auth`.
+
+_Note: The regex is matched against the full name, which is a combination of the
+test name and all its surrounding describe blocks._
+
+### `--testLocationInResults`
+
+Adds a `location` field to test results. Useful if you want to report the
+location of a test in a reporter.
+
+Note that `column` is 0-indexed while `line` is not.
+
+```json
+{
+  "column": 4,
+  "line": 5
+}
+```
+
+### `--testPathPattern=<regex>`
+
+A regexp pattern string that is matched against all tests paths before executing
+the test. On Windows, you will need to use `/` as a path separator or escape `\`
+as `\\`.
+
+### `--testRunner=<path>`
+
+Lets you specify a custom test runner.
+
+### `--updateSnapshot`
+
+Alias: `-u`. Use this flag to re-record every snapshot that fails during this
+test run. Can be used together with a test suite pattern or with
+`--testNamePattern` to re-record snapshots.
+
+### `--useStderr`
+
+Divert all output to stderr.
+
+### `--verbose`
+
+Display individual test results with the test suite hierarchy.
+
+### `--version`
+
+Alias: `-v`. Print the version and exit.
+
+### `--watch`
+
+Watch files for changes and rerun tests related to changed files. If you want to
+re-run all tests when a file has changed, use the `--watchAll` option instead.
+
+### `--watchAll`
+
+Watch files for changes and rerun all tests when something changes. If you want
+to re-run only the tests that depend on the changed files, use the `--watch`
+option.
+
+### `--watchman`
+
+Whether to use watchman for file crawling. Defaults to true. Disable using
+`--no-watchman`.