flow-phabricator-parser

A flow output parser to be use with phabricator arc lint

This is a simple wrapper - parser for node that will transform the output from flow to something that phabricator can inspect in the linting stage.

How to use it.

Install the package with

npm install flow-phabricator-parser --save-dev
#or
yarn add flow-phabricator-parser --dev

or copy the source file to your project.

To configure the script with arc lint create a .arclint file and add

{
  "linters": {
    ....
  "flow-regex-based": {
    "type": "script-and-regex",
    "include": "(\\.js?$)",
    "exclude": [ ],
    "script-and-regex.script": "sh -c '(node ./PATH_FROM_REPO_ROOT_TO_PROJECT/node_modules/flow-phabricator-parser/flowparser.js ./PATH_FROM_REPO_ROOT_TO_FLOWCONFIG \"$0\")'",
    "script-and-regex.regex": "/^(?P<file>.*): line (?P<line>[0-9]*), col (?P<char>[0-9]*), (?P<severity>error|warning) - (?P<message>.*) \\((?P<code>[a-z-]+)\\)$/m"
    }
  }
}

Replace PATH_FROM_REPO_ROOT_TO_FLOWCONFIG in the above with the path to directory containing your project's project.json file. If it's at the root, remove /PATH_FROM_REPO_ROOT_TO_FLOWCONFIG from the path above - including the / prefix, so just . is left. An optional parameter check can be pass at the end to the script so the line will look like

"script-and-regex.script": "sh -c '(node ./PATH_FROM_REPO_ROOT_TO_PROJECT/node_modules/flow-phabricator-parser/flowparser.js ./PATH_FROM_REPO_ROOT_TO_FLOWCONFIG \"$0\" check)'",

That will force to run flow in mode "check" (independent process) instead of status (server). Flow #6025 and Flow #1428 are issues that can be work around with this. Flow modes

Next we need to ensure the appropriate version of flow-bin is installed.

• Open up .flowconfig file at the root of your React Native project, and scroll to the bottom.

You should see a version, e.g.:

[version]
^0.42.0

Install that version of flow-bin with:

npm install flow-bin@0.42.0 --save-dev
# or
yarn add flow-bin@0.42.0 --dev

Notes

We point to "(\\.js?$)", to get all the js files changed since last version. Also the parser will discard errors that doesn't belong to changed files. If you think some error reported is cryptic you may want to run flow in your project folder.

On

"script-and-regex.script": "sh -c '(node ./ProjectDir/node_modules/flow-phabricator-parser/flowparser.js ./ProjectDir \"$0\")'"

we need to pass ./ProjectDir as the folder where flow will be run (AKA the folder of your .flowconfig file) relative to the root of the git repository.

Current Limitations

• Flow is invoked for each file and the output processed for each different file.
• Right now, in very big projects with many dependencies in node_modules; errors in the parsing are not impossible although really unlikely. To solve this we may need to move from execFile to a more robust mechanism.