fastlint

Lint faster by only running linters and other tools on files that have recently changed or files that are different from master in git.

Installation

npm install -g fastlint

Changelog

• v1.1.0: added --staged filter, added support for cwd-relative globs.

Usage examples

fastlint --status

Runs fastlint and shows the current set of filters (in stderr).

fastlint --status --print0 | xargs -0 eslint

Run eslint on all modified files in the working copy.

fastlint --status --print0 --working-copy HEAD~5 HEAD | xargs -0 eslint

Run eslint on all files changed in the working copy and in the last five commits in this branch.

fastlint origin/master HEAD | xargs -0 eslint

Run eslint on all files changed compared to the origin/master branch.

fastlint --status --print0 --glob '{src,tests}/**/*.{js,jsx}' origin/master HEAD | xargs -0 eslint

Run eslint on all .js and .jsx files in src/ or tests/ changed compared to the origin/master branch.

Integrating with package.json

Here is an example of a full integration inside package.json, runnable via npm run-script fastlint:

  "scripts": {
    "fastlint": "fastlint --status --print0 --glob '{src,tests}/**/*.{js,jsx}' --glob './webpack*.js' --working-copy --diff-filter=buxq origin/master HEAD | xargs -0 eslint --cache --fix --ext js,jsx || exit 0"
  },

CLI options

Filtering

--glob [glob]. Use a glob to filter the results. Can be specified multiple times. The matching is processed using multimatch, see their docs for details. You can use ./{glob} to specify that the glob should match local files (since v.1.1.0)

--working-copy. fastlint can also include files in the working copy, e.g. files that have been added/modified but not necessarily staged. For UX reasons this gets set if you don't pass anything in (because otherwise there would be nothing to show if you don't pass two branches to compare).

To only include untracked files, use --diff-filter=Q. To only include tracked files, use --diff-filter=q.

--diff-filter [(A|C|D|M|R|T|U|X|B|Q)]. Only select files that are Added (A), Copied (C), Deleted (D), Modified (M), Renamed (R), have their type (i.e. regular file, symlink, submodule, …​) changed (T), are Untracked (Q), Unmerged (U), are Unknown (X), or have had their pairing Broken (B). Any combination of the filter characters (including none) can be used.

Also, these upper-case letters can be downcased to exclude. E.g. --diff-filter=ad excludes added and deleted paths.

Note that "Deleted" does not necessarily mean the file was deleted - it may refer to the file being only modified by deleting lines.

--staged. Filter files by their staging status. Defaults to not applying any filtering. To select unstaged files, use --no-staged. This only applies to files in the working copy, since any committed files are considered staged.

Imagine you run git status. Here's how the output maps to the two filters:

	diff-filter	staged
"Changes to be committed"	q (any, not untracked)	staged
"Changes not staged for commit"	q (any, not untracked)	no-staged
"Untracked files"	Q (untracked)	no-staged

Human friendly status

--status logs out the list of selected files to stderr.

Result formatting

• --delimiter [character]. Join the filenames using this delimiter. \n, \t, \r and \0 are converted to the appropriate character. Default: .
• --print0. Same as --delimiter '\0'.
• --paths cwd. Output paths relative to CWD. Default.
• --paths full. Output full paths.
• --paths gitroot. Output paths relative to the location of the closest .git folder, searching up from the current working directory.