.flowconfig should use json

[darrenderidder]

The config file format should be JSON to allow better tooling integration, rather than an ad-hoc format.

+1

[j201]

JSON is a bit painful for regex because it doesn't support raw strings. I think the current format is reasonable given its similarity to other dotfiles, but it might be worth looking at alternatives like YAML or just providing a tool on npm that can read a .flowconfig file.

[gabelevi]

I'm 100% open to a different format. JSON with only literals would be pretty easy to support. We do have a JS parser, so as long as we don't need to execute code it should be pretty easy.

@j201 is right, specifying regex's would be a little worse in JSON, but it doesn't seem terrible

[StyMaar]

I quite agree with j201 about regex. Dealling with double backslashes is really annoying. Regex are cryptic enough without it ... I would rather have a parser on npm as suggested by j201.

[thomasboyt]

TOML may be a good alternative. It's relatively common (though not as popular as JSON or YAML), very simple, and has parsers for OCaml and JS. It also has a raw string syntax that may make regexes easier (see the bottom of this section).

[gabelevi]

I suppose this would be a good issue to resolve sooner rather than later, as it would be a breaking-ish change (I suppose we could support both for a while).

Do you guys have strong opinions of TOML vs YAML? I do like TOML's simplicity, but there's something to be said for using something that's more mature and well specified. I think I'm leaning towards TOML.

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[monolithed]

+1

[j201]

+1 for TOML

[jasonkuhrt]

YAML. Its very common in a range of communities, though in JS JSON generally rules even though it was optimized for machines and YAML for us. YAML is supported by testem, eslint, and surely more.

+1 for YAML.

-- EDIT June 2017: I would no longer advocate for YAML even though I prefer the format. JSON would allow configuration to go into package.json. This is the ideal consolidation I think

[m-alikhizar]

+1

[trevordmiller]

Has there been any progress on this? Would be great if JSON config could be supported as both a standalone file and a property in package.json files as Babel, Jest, ESLint, and many other tools in the ecosystem do so you could do something like:

.flowrc.json or whatever the file is called

{
  "include": [
    "../otherdir/src"
  ],
  "ignore": [
    ".*/build/.*"
  ],
  "libs": [
    "./lib"
  ]
},

Or

package.json

{
  "name": "some-app",
  "version": "1.0.0",
  "scripts": {
    ...
  },
  "flow": {
    "include": [
      "../otherdir/src"
    ],
    "ignore": [
      ".*/build/.*"
    ],
    "libs": [
      "./lib"
    ]
  },
  "babel": {
    ...
  },
  "jest": {
    ...
  },
  "devDependencies": {
    ...
  },
  "dependencies": {
    ...
  }
}