unified-diff

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[unified][] plugin to ignore unrelated messages in GitHub Actions and
Travis.

Contents

* What is this?
* When should I use this?
* Install
* Use
* API
* unified().use(unifiedDiff)
* Types
* Compatibility
* Contribute
* License

What is this?

This package is a [unified][] plugin to ignore unrelated lint messages in a CI.

unified is a project that transforms content with abstract syntax trees
(ASTs).
vfile is the virtual file interface used in unified which manages messages.
This is a unified plugin that filters messages on the vfile.

When should I use this?

You can use this plugin when you are dealing with a large, existing project.

Using tools that check whether things follow a style guide is typically very
useful.
However, it can be hard to start using something in a large existing project.
This plugin helps, because it ignores messages that occur in lines that are not
touched by a PR in a CI.
When this plugin is used outside of a supported CIs, it doesn’t do anything.

Install

This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:

``sh
npm install unified-diff
`

In Deno with [esm.sh][esmsh]:

`js
import unifiedDiff from 'https://esm.sh/unified-diff@5'
`

In browsers with [esm.sh][esmsh]:

`html

`

Use

Say our document example.md contains:

`markdown
This is an an example.
`

> 👉 Note: an an is a typo.

…and our module example.js looks as follows:

`js
import process from 'node:process'
import remarkParse from 'remark-parse'
import remarkRetext from 'remark-retext'
import remarkStringify from 'remark-stringify'
import retextEnglish from 'retext-english'
import retextIndefiniteArticle from 'retext-indefinite-article'
import retextRepeatedWords from 'retext-repeated-words'
import {read} from 'to-vfile'
import {unified} from 'unified'
import unifiedDiff from 'unified-diff'
import {reporter} from 'vfile-reporter'

const file = await unified()
.use(remarkParse)
.use(
remarkRetext,
unified()
.use(retextEnglish)
.use(retextRepeatedWords)
.use(retextIndefiniteArticle)
)
.use(remarkStringify)
.use(unifiedDiff)
.process(await read('example.md'))

console.error(reporter(file))
process.exitCode = file.messages.length > 0 ? 1 : 0
`

…and our Travis configuration .travis.yml contains:

`yml


…

script:
- npm test
- node example.js

…

`

> 👉 Note: an equivalent GH Actions workflow file is also supported.

Then, say someone creates a PR which adds the following diff:

`diff
diff --git a/example.md b/example.md
index 360b225..5a96b86 100644
--- a/example.md
+++ b/example.md
@@ -1 +1,3 @@
This is an an example.
+
+Some more more text. A error.
`

> 👉 Note: more more and A before error are typos.

When run in CI, we’ll see the following printed on stderr(4).

`txt
example.md
3:6-3:15 warning Expected more once, not twice retext-repeated-words retext-repeated-words
3:22-3:23 warning Use An before error, not A retext-indefinite-article retext-indefinite-article

⚠ 2 warnings
`

> 👉 Note: an an on L1 is not included because it’s unrelated to this PR.

The build exits with 1 as there are messages, thus failing CI.
The user sees this and amends the PR to the following:

`diff
diff --git a/example.md b/example.md
index 360b225..5a96b86 100644
--- a/example.md
+++ b/example.md
@@ -1 +1,3 @@
This is an an example.
+
+Some more text. An error.
`

This time our lint task exits successfully, even though L1 would normally emit
an error, but it’s unrelated to the PR.

API

This package exports no identifiers.
The default export is [unifiedDiff][api-unified-diff].

$3

Ignore unrelated messages in GitHub Actions and Travis.

There are no options.
If there’s a TRAVIS_COMMIT_RANGE, GITHUB_BASE_REF and GITHUB_HEAD_REF, or
GITHUB_SHA environment variable, then this plugin runs, otherwise it does
nothing.

###### To do

* [ ] Add support for other CIs (ping if you want to work on this)
* [ ] Add non-CI support (I’m not sure how though)

PRs welcome!

###### Returns

Transform ([Transformer][transformer]).

Types

This package is fully typed with [TypeScript][].
It exports no additional types.

Compatibility

Projects maintained by the unified collective are compatible with maintained
versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of
Node.
This means we try to keep the current release line, unified-diff@^5,
compatible with Node.js 16.

Contribute

See [contributing.md][contributing] in [unifiedjs/.github][health] for ways
to get started.
See [support.md`][support] for ways to get help.

This project has a [code of conduct][coc].
By interacting with this repository, organization, or community you agree to
abide by its terms.

License

[MIT][license] © [Titus Wormer][author]

[build-badge]: https://github.com/unifiedjs/unified-diff/workflows/main/badge.svg

[build]: https://github.com/unifiedjs/unified-diff/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/unifiedjs/unified-diff.svg

[coverage]: https://codecov.io/github/unifiedjs/unified-diff

[downloads-badge]: https://img.shields.io/npm/dm/unified-diff.svg

[downloads]: https://www.npmjs.com/package/unified-diff

[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg

[backers-badge]: https://opencollective.com/unified/backers/badge.svg

[collective]: https://opencollective.com/unified

[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg

[chat]: https://github.com/unifiedjs/unified/discussions

[npm]: https://docs.npmjs.com/cli/install

[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[esmsh]: https://esm.sh

[typescript]: https://www.typescriptlang.org

[health]: https://github.com/unifiedjs/.github

[contributing]: https://github.com/unifiedjs/.github/blob/main/contributing.md

[support]: https://github.com/unifiedjs/.github/blob/main/support.md

[coc]: https://github.com/unifiedjs/.github/blob/main/code-of-conduct.md

[license]: license

[author]: https://wooorm.com

[unified]: https://github.com/unifiedjs/unified

[transformer]: https://github.com/unifiedjs/unified?tab=readme-ov-file#transformer

[api-unified-diff]: #unifieduseunifieddiff