+## blackd
+
+`blackd` is a small HTTP server that exposes _Black_'s functionality over a simple
+protocol. The main benefit of using it is to avoid paying the cost of starting up a new
+_Black_ process every time you want to blacken a file.
+
+### Usage
+
+`blackd` is not packaged alongside _Black_ by default because it has additional
+dependencies. You will need to do `pip install black[d]` to install it.
+
+You can start the server on the default port, binding only to the local interface by
+running `blackd`. You will see a single line mentioning the server's version, and the
+host and port it's listening on. `blackd` will then print an access log similar to most
+web servers on standard output, merged with any exception traces caused by invalid
+formatting requests.
+
+`blackd` provides even less options than _Black_. You can see them by running
+`blackd --help`:
+
+```text
+Usage: blackd [OPTIONS]
+
+Options:
+ --bind-host TEXT Address to bind the server to.
+ --bind-port INTEGER Port to listen on
+ --version Show the version and exit.
+ -h, --help Show this message and exit.
+```
+
+There is no official blackd client tool (yet!). You can test that blackd is working
+using `curl`:
+
+```sh
+blackd --bind-port 9090 & # or let blackd choose a port
+curl -s -XPOST "localhost:9090" -d "print('valid')"
+```
+
+### Protocol
+
+`blackd` only accepts `POST` requests at the `/` path. The body of the request should
+contain the python source code to be formatted, encoded according to the `charset` field
+in the `Content-Type` request header. If no `charset` is specified, `blackd` assumes
+`UTF-8`.
+
+There are a few HTTP headers that control how the source is formatted. These correspond
+to command line flags for _Black_. There is one exception to this: `X-Protocol-Version`
+which if present, should have the value `1`, otherwise the request is rejected with
+`HTTP 501` (Not Implemented).
+
+The headers controlling how code is formatted are:
+
+- `X-Line-Length`: corresponds to the `--line-length` command line flag.
+- `X-Skip-String-Normalization`: corresponds to the `--skip-string-normalization`
+ command line flag. If present and its value is not the empty string, no string
+ normalization will be performed.
+- `X-Fast-Or-Safe`: if set to `fast`, `blackd` will act as _Black_ does when passed the
+ `--fast` command line flag.
+- `X-Python-Variant`: if set to `pyi`, `blackd` will act as _Black_ does when passed the
+ `--pyi` command line flag. Otherwise, its value must correspond to a Python version or
+ a set of comma-separated Python versions, optionally prefixed with `py`. For example,
+ to request code that is compatible with Python 3.5 and 3.6, set the header to
+ `py3.5,py3.6`.
+- `X-Diff`: corresponds to the `--diff` command line flag. If present, a diff of the
+ formats will be output.
+
+If any of these headers are set to invalid values, `blackd` returns a `HTTP 400` error
+response, mentioning the name of the problematic header in the message body.
+
+Apart from the above, `blackd` can produce the following response codes:
+
+- `HTTP 204`: If the input is already well-formatted. The response body is empty.
+- `HTTP 200`: If formatting was needed on the input. The response body contains the
+ blackened Python code, and the `Content-Type` header is set accordingly.
+- `HTTP 400`: If the input contains a syntax error. Details of the error are returned in
+ the response body.
+- `HTTP 500`: If there was any kind of error while trying to format the input. The
+ response body contains a textual representation of the error.
+
+The response headers include a `X-Black-Version` header containing the version of
+_Black_.
+
+## black-primer
+
+`black-primer` is a tool built for CI (and huumans) to have _Black_ `--check` a number
+of (configured in `primer.json`) Git accessible projects in parallel. _(A PR will be
+accepted to add Mercurial support.)_
+
+### Run flow
+
+- Ensure we have a `black` + `git` in PATH
+- Load projects from `primer.json`
+- Run projects in parallel with `--worker` workers (defaults to CPU count / 2)
+ - Checkout projects
+ - Run black and record result
+ - Clean up repository checkout _(can optionally be disabled via `--keep`)_
+- Display results summary to screen
+- Default to cleaning up `--work-dir` (which defaults to tempfile schemantics)
+- Return
+ - 0 for successful run
+ - < 0 for environment / internal error
+ - > 0 for each project with an error
+
+### Speed up Runs 🏎
+
+If you're running locally yourself to test black on lots of code try:
+
+- Using `-k` / `--keep` + `-w` / `--work-dir` so you don't have to re-checkout the repo
+ each run
+
+### CLI Arguments
+
+```text
+Usage: black-primer [OPTIONS]
+
+ primer - prime projects for blackening... 🏴
+
+Options:
+ -c, --config PATH JSON config file path [default: /Users/cooper/repos/
+ black/src/black_primer/primer.json]
+
+ --debug Turn on debug logging [default: False]
+ -k, --keep Keep workdir + repos post run [default: False]
+ -L, --long-checkouts Pull big projects to test [default: False]
+ -R, --rebase Rebase project if already checked out [default:
+ False]
+
+ -w, --workdir PATH Directory Path for repo checkouts [default: /var/fol
+ ders/tc/hbwxh76j1hn6gqjd2n2sjn4j9k1glp/T/primer.20200
+ 517125229]
+
+ -W, --workers INTEGER Number of parallel worker coroutines [default: 69]
+ -h, --help Show this message and exit.
+```
+
+### primer config file
+
+The config is JSON format. Its main element is the `"projects"` dictionary. Below
+explains each parameter:
+
+```json
+{
+ "projects": {
+ "00_Example": {
+ "cli_arguments": "List of extra CLI arguments to pass Black for this project",
+ "expect_formatting_changes": "Boolean to indicate that the version of Black is expected to cause changes",
+ "git_clone_url": "URL you would pass `git clone` to check out this repo",
+ "long_checkout": "Boolean to have repo skipped by defauult unless `--long-checkouts` is specified",
+ "py_versions": "List of major Python versions to run this project with - all will do as you'd expect - run on ALL versions"
+ },
+ "aioexabgp": {
+ "cli_arguments": [],
+ "expect_formatting_changes": true,
+ "git_clone_url": "https://github.com/cooperlees/aioexabgp.git",
+ "long_checkout": false,
+ "py_versions": ["all", "3.8"] // "all" ignores all other versions
+ }
+ }
+}
+```
+
+### Example run
+
+```console
+cooper-mbp:black cooper$ ~/venvs/b/bin/black-primer
+[2020-05-17 13:06:40,830] INFO: 4 projects to run Black over (lib.py:270)
+[2020-05-17 13:06:44,215] INFO: Analyzing results (lib.py:285)
+-- primer results 📊 --
+
+3 / 4 succeeded (75.0%) ✅
+1 / 4 FAILED (25.0%) 💩
+ - 0 projects disabled by config
+ - 0 projects skipped due to Python version
+ - 0 skipped due to long checkout
+
+Failed projects:
+
+### flake8-bugbear:
+ - Returned 1
+ - stdout:
+--- tests/b303_b304.py 2020-05-17 20:04:09.991227 +0000
++++ tests/b303_b304.py 2020-05-17 20:06:42.753851 +0000
+@@ -26,11 +26,11 @@
+ maxint = 5 # this is okay
+ # the following shouldn't crash
+ (a, b, c) = list(range(3))
+ # it's different than this
+ a, b, c = list(range(3))
+- a, b, c, = list(range(3))
++ a, b, c = list(range(3))
+ # and different than this
+ (a, b), c = list(range(3))
+ a, *b, c = [1, 2, 3, 4, 5]
+ b[1:3] = [0, 0]
+
+would reformat tests/b303_b304.py
+Oh no! 💥 💔 💥
+1 file would be reformatted, 22 files would be left unchanged.
+```
+
+## Version control integration
+
+Use [pre-commit](https://pre-commit.com/). Once you
+[have it installed](https://pre-commit.com/#install), add this to the
+`.pre-commit-config.yaml` in your repository:
+
+```yaml
+repos:
+ - repo: https://github.com/psf/black
+ rev: stable
+ hooks:
+ - id: black
+ language_version: python3.6
+```
+
+Then run `pre-commit install` and you're ready to go.
+
+Avoid using `args` in the hook. Instead, store necessary configuration in
+`pyproject.toml` so that editors and command-line usage of Black all behave consistently
+for your project. See _Black_'s own
+[pyproject.toml](https://github.com/psf/black/blob/master/pyproject.toml) for an
+example.
+
+If you're already using Python 3.7, switch the `language_version` accordingly. Finally,
+`stable` is a branch that tracks the latest release on PyPI. If you'd rather run on
+master, this is also an option.
+
+## Ignoring unmodified files
+
+_Black_ remembers files it has already formatted, unless the `--diff` flag is used or
+code is passed via standard input. This information is stored per-user. The exact
+location of the file depends on the _Black_ version and the system on which _Black_ is
+run. The file is non-portable. The standard location on common operating systems is:
+
+- Windows:
+ `C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.<file-mode>.pickle`
+- macOS:
+ `/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.<file-mode>.pickle`
+- Linux:
+ `/home/<username>/.cache/black/<version>/cache.<line-length>.<file-mode>.pickle`
+
+`file-mode` is an int flag that determines whether the file was formatted as 3.6+ only,
+as .pyi, and whether string normalization was omitted.
+
+To override the location of these files on macOS or Linux, set the environment variable
+`XDG_CACHE_HOME` to your preferred location. For example, if you want to put the cache
+in the directory you're running _Black_ from, set `XDG_CACHE_HOME=.cache`. _Black_ will
+then write the above files to `.cache/black/<version>/`.
+
+## Used by
+
+The following notable open-source projects trust _Black_ with enforcing a consistent
+code style: pytest, tox, Pyramid, Django Channels, Hypothesis, attrs, SQLAlchemy,
+Poetry, PyPA applications (Warehouse, Bandersnatch, Pipenv, virtualenv), pandas, Pillow,
+every Datadog Agent Integration, Home Assistant.
+
+The following organizations use _Black_: Facebook, Dropbox.
+
+Are we missing anyone? Let us know.
+
+## Testimonials
+
+**Dusty Phillips**,
+[writer](https://smile.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=dusty+phillips):
+
+> _Black_ is opinionated so you don't have to be.
+
+**Hynek Schlawack**, [creator of `attrs`](https://www.attrs.org/), core developer of
+Twisted and CPython:
+
+> An auto-formatter that doesn't suck is all I want for Xmas!
+
+**Carl Meyer**, [Django](https://www.djangoproject.com/) core developer:
+
+> At least the name is good.
+
+**Kenneth Reitz**, creator of [`requests`](http://python-requests.org/) and
+[`pipenv`](https://docs.pipenv.org/):
+
+> This vastly improves the formatting of our code. Thanks a ton!
+
+## Show your style
+
+Use the badge in your project's README.md:
+
+```markdown
+[](https://github.com/psf/black)
+```
+
+Using the badge in README.rst:
+
+```
+.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
+ :target: https://github.com/psf/black
+```
+
+Looks like this:
+[](https://github.com/psf/black)
+
+## License
+
+MIT
+
+## Contributing to _Black_
+
+In terms of inspiration, _Black_ is about as configurable as _gofmt_. This is
+deliberate.
+
+Bug reports and fixes are always welcome! However, before you suggest a new feature or
+configuration knob, ask yourself why you want it. If it enables better integration with
+some workflow, fixes an inconsistency, speeds things up, and so on - go for it! On the
+other hand, if your answer is "because I don't like a particular formatting" then you're
+not ready to embrace _Black_ yet. Such changes are unlikely to get accepted. You can
+still try but prepare to be disappointed.
+
+More details can be found in
+[CONTRIBUTING](https://github.com/psf/black/blob/master/CONTRIBUTING.md).
+
+## Change Log
+
+The log's become rather long. It moved to its own file.
+
+See [CHANGES](https://github.com/psf/black/blob/master/CHANGES.md).
projects / etc / vim.git / blobdiff