Disable advanced terminal behavior when TERM is dumb

[sQVe]

Description

lint-staged needs to respect when TERM is dumb and output simple information. This fixes issues in applications / plugins like vim-fugitive. An example is how chalk respects this here: https://github.com/chalk/supports-color/blob/8a40054cdbcd3f42b4f68eaefb41c3064835b991/index.js#L65-L67

Reference: tpope/vim-fugitive#1446

Steps to reproduce

Running:

% export TERM=dumb && npx lint-staged
  ✔ Preparing...
  ✔ Running tasks...
  ✔ Applying modifications...
  ✔ Cleaning up...

Should output more simple information like:

% npx lint-staged | cat                                                                                                                                  ~/code/righttp develop +
Preparing... [started]
Preparing... [completed]
Running tasks... [started]
Running tasks for *.{js,jsx,ts,tsx} [started]
Running tasks for *.json [started]
Running tasks for *.json [skipped]
→ No staged files match *.json
prettier --write [started]
prettier --write [completed]
eslint --fix [started]
eslint --fix [completed]
jest --findRelatedTests [started]
jest --findRelatedTests [completed]
Running tasks for *.{js,jsx,ts,tsx} [completed]
Running tasks... [completed]
Applying modifications... [started]
Applying modifications... [completed]
Cleaning up... [started]
Cleaning up... [completed]

Debug Logs

expand to view

  lint-staged:bin Running `lint-staged@10.0.1` +0ms
  lint-staged:bin Options parsed from command-line: { allowEmpty: false,
  concurrent: true,
  configPath: undefined,
  debug: true,
  maxArgLength: 65536,
  quiet: false,
  relative: false,
  shell: false } +4ms
  lint-staged Loading config using `cosmiconfig` +0ms
  lint-staged Successfully loaded config from `/home/sqve/code/righttp/.lintstagedrc.json`:
  lint-staged { '*.{js,jsx,ts,tsx}':
  lint-staged    [ 'prettier --write', 'eslint --fix', 'jest --findRelatedTests' ],
  lint-staged   '*.json': [ 'prettier --write' ] } +13ms
  lint-staged:cfg Validating config +0ms
  lint-staged:run Running all linter scripts +0ms
  lint-staged:git Running git command [ 'rev-parse', '--show-toplevel' ] +0ms
  lint-staged:git Running git command [ 'rev-parse', '--show-superproject-working-tree' ] +19ms
  lint-staged:run Resolved git directory to be `/home/sqve/code/righttp` +29ms
  lint-staged:run Resolved git config directory to be `/home/sqve/code/righttp/.git` +1ms
  lint-staged:git Running git command [ 'diff', '--staged', '--diff-filter=ACMR', '--name-only' ] +10ms
  lint-staged:run Loaded list of staged files in git:
  lint-staged:run [ 'src/types.ts' ] +9ms
  lint-staged:chunkFiles Resolved an argument string length of 36 characters from 1 files +0ms
  lint-staged:chunkFiles Creating 1 chunks for maxArgLength of 65536 +0ms
  lint-staged:gen-tasks Generating linter tasks +0ms
  lint-staged:gen-tasks Generated task:
  lint-staged:gen-tasks { pattern: '*.{js,jsx,ts,tsx}',
  lint-staged:gen-tasks   commands:
  lint-staged:gen-tasks    [ 'prettier --write', 'eslint --fix', 'jest --findRelatedTests' ],
  lint-staged:gen-tasks   fileList: [ '/home/sqve/code/righttp/src/types.ts' ] } +6ms
  lint-staged:gen-tasks Generated task:
  lint-staged:gen-tasks { pattern: '*.json',
  lint-staged:gen-tasks   commands: [ 'prettier --write' ],
  lint-staged:gen-tasks   fileList: [] } +1ms
  lint-staged:make-cmd-tasks Creating listr tasks for commands [ 'prettier --write', 'eslint --fix', 'jest --findRelatedTests' ] +0ms
  lint-staged:task cmd: prettier --write /home/sqve/code/righttp/src/types.ts +0ms
  lint-staged:task execaOptions: { preferLocal: true, reject: false, shell: false } +0ms
  lint-staged:task cmd: eslint --fix /home/sqve/code/righttp/src/types.ts +1ms
  lint-staged:task execaOptions: { preferLocal: true, reject: false, shell: false } +0ms
  lint-staged:task cmd: jest --findRelatedTests /home/sqve/code/righttp/src/types.ts +0ms
  lint-staged:task execaOptions: { preferLocal: true, reject: false, shell: false } +0ms
  lint-staged:make-cmd-tasks Creating listr tasks for commands [ 'prettier --write' ] +2ms
  lint-staged:task cmd: prettier --write  +0ms
  lint-staged:task execaOptions: { preferLocal: true, reject: false, shell: false } +0ms
  lint-staged:git Backing up original state... +0ms
  lint-staged:git Backing up merge state... +0ms
  lint-staged:file Reading buffer from file `/home/sqve/code/righttp/.git/MERGE_HEAD` +0ms
  lint-staged:file Reading buffer from file `/home/sqve/code/righttp/.git/MERGE_MODE` +0ms
  lint-staged:file Reading buffer from file `/home/sqve/code/righttp/.git/MERGE_MSG` +0ms
  lint-staged:file File `/home/sqve/code/righttp/.git/MERGE_HEAD` doesn't exist, ignoring... +1ms
  lint-staged:file File `/home/sqve/code/righttp/.git/MERGE_MODE` doesn't exist, ignoring... +0ms
  lint-staged:file File `/home/sqve/code/righttp/.git/MERGE_MSG` doesn't exist, ignoring... +0ms
  lint-staged:git Done backing up merge state! +2ms
  lint-staged:git Running git command [ 'stash',
  'save',
  '--quiet',
  '--include-untracked',
  '--keep-index',
  'lint-staged automatic backup' ] +26ms
  lint-staged:git Restoring merge state... +46ms
  lint-staged:git Done restoring merge state! +0ms
  lint-staged:git Running git command [ 'ls-files', '--others', '--exclude-standard' ] +47ms
  lint-staged:git Running git command [ 'stash', 'list' ] +7ms
  lint-staged:git Running git command [ 'diff',
  '--binary',
  '--unified=0',
  '--no-color',
  '--no-ext-diff',
  '--patch',
  'stash@{0}',
  '-R' ] +8ms
  lint-staged:git Done backing up original state! +25ms
  lint-staged:git Running git command [ 'ls-files', '--modified' ] +8s
  lint-staged:git Running git command [ 'status', '--porcelain' ] +6ms
  lint-staged:git Restoring unstaged changes... +8s
  lint-staged:git Running git command [ 'apply',
  '-v',
  '--whitespace=nowarn',
  '--recount',
  '--unidiff-zero' ] +6ms
  lint-staged:git Done restoring unstaged changes! +10ms
  lint-staged:git Running git command [ 'stash', 'list' ] +9ms
  lint-staged:git Running git command [ 'show', '--format=%b', 'stash@{0}^3' ] +10ms
  lint-staged:git Dropping backup stash... +19ms
  lint-staged:git Running git command [ 'stash', 'list' ] +9ms
  lint-staged:git Running git command [ 'stash', 'drop', '--quiet', 'stash@{0}' ] +11ms
  lint-staged:git Done dropping backup stash! +27ms
  lint-staged tasks were executed successfully! +8s

Environment

• OS: Arch Linux, 5.4.15
• Node.js: v10.18.1
• lint-staged: 10.0.1

[iiroj]

Thanks for the issue! Since it seems simple, I went ahead and implemented it at #782.

Question: we use chalk to support colored output, but it doesn't seem to react itself to this variable. Should it?

[sQVe]

@iiroj I would assume that it, but I'm unsure. Nicely done with the quick fix!

[tpope]

lint-staged appears to be setting FORCE_COLOR for all ttys, which has higher precedence than TERM=dumb in chalk's supports-color library. A conservative change would be to add a TERM check to this conditional. It appears this behavior was added in #50 for, frankly, dubious reasons (at least from an outsider's perspective); I would recommend reassessing if it's still necessary.

https://github.com/okonet/lint-staged/blob/4010db09f6d168af677bd4ca1c815ba40460ae80/bin/lint-staged#L7-L10

[tpope]

Now that I think about it, the right way to do this probably is to use supports-color itself to decide whether to force color support down the line:

const supportsColor = require('supports-color');
if (supportsColor.stdout) {
  process.env.FORCE_COLOR = supportsColor.stdout.level.toString();
}

(Edit: Added .level.toString().)

[iiroj]

Thanks for the tip, @tpope, I added it to the PR! It's a shame to add a new dependency, but then again it was already in via chalk.

[tpope]

My reading of chalk's README is that you can use chalk.supportsColor directly to get the same effect.

[iiroj]

@tpope Perfect, thanks for finding that. Made the change a bit simpler: 6803f6a

[okonet]

🎉 This issue has been resolved in version 10.0.4 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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