Inherit standard configuration from parent package.json

[timoxley]

Problem

standard currently does not check directories above cwd for package.json files containing standard configuration.

Example

Say I have A & A/B directories, both with their own package.json files:

A
├── package.json
├── index.js
└── B
    ├── package.json
    └── index.js

Let's suppose B/index.js contains some syntax that requires the babel-eslint parser:

class A {
  // class properties are not supported by vanilla eslint
  static classProperty = 'ok'
}

console.log(A.classProperty)

standard will behave differently depending on what the current directory is:

> cd A
> standard B/index.js && echo 'ok'
ok
> cd B
> standard index.js && echo 'ok'
standard: Use JavaScript Standard Style (http://standardjs.com)
  /Users/timoxley/Projects/tests/standard-config/A/B/index.js:3:24: Parsing error: Unexpected token =

At first, not reading parent directories for configuration does seem like reasonable behaviour, though it differs from that of babel, which finds all the configs in all parents, then merges the results:

https://github.com/babel/babel/blob/210c3f7da92a7bd9b6da8fb57dac38996222fecd/packages/babel-core/src/transformation/file/options/build-config-chain.js#L26

While standard appears to just find the nearest package.json whether it has a "standard" config or not: https://github.com/Flet/standard-engine/blob/9ddbe6cce2dd43f3d888b64aede48ef3190d2e34/index.js#L136

Proposal

I suggest standard should follow the lead of babel here and inherit parent configs. I'd be happy if it just searched up until it found the first "standard" config, but I think perhaps a "standard" for config behaviour across all tools that read config from package.json/.rc files is better than minimalism. Ideally a reusable package could be used for keeping this consistent.

[feross]

This sounds reasonable to me.

We currently use find-root to find the nearest package.json. What does babel use?

[timoxley]

Babel uses its own custom "config chain".
See https://github.com/babel/babel/blob/210c3f7da92a7bd9b6da8fb57dac38996222fecd/packages/babel-core/src/transformation/file/options/build-config-chain.js