feat(lint-staged): add .USAGE.md → README.md

So that it's not needed to manually runs from `normalize-packages.js`.

package.json

@@ -89,6 +89,7 @@
       "eslint",
       "jest --testRegex='^(?!.*.integ.spec.js$).*.spec.js$' --findRelatedTests --passWithNoTests"
     ],
+    ".USAGE.md": "scripts/usage-to-readme.js --git-add",
     "./CHANGELOG.unreleased.md": "sh -c scripts/gen-deps-list.js --"
   },
   "private": true,

scripts/normalize-packages.js

@@ -5,7 +5,9 @@
 const isEmpty = require('lodash/isEmpty')
 const sortedObject = require('sorted-object')
 const { dirname, join, relative } = require('path')
-const { getPackages, noop, readFile, symlink, writeFile, unlink } = require('./utils')
+
+const usageToReadme = require('./usage-to-readme.js')
+const { getPackages, noop, symlink, writeFile, unlink } = require('./utils')
 
 const BABEL_ESLINTRC_PATH = join(__dirname, 'babel-eslintrc.js')
 const NPMIGNORE_PATH = join(__dirname, 'npmignore')
@@ -27,10 +29,6 @@ const deleteProperties = (object, property, properties) => {
   deleteIfEmpty(object, property)
 }
 
-const generateReadme = require('handlebars').compile(
-  require('fs').readFileSync(join(__dirname, 'README.md.tpl'), 'utf8')
-)
-
 const forceRelativeSymlink = async (target, path) => {
   await unlink(path).catch(noop)
   return symlink(relative(dirname(path), target), path)
@@ -128,21 +126,11 @@ require('exec-promise')(() =>
 
     return Promise.all([
       forceRelativeSymlink(NPMIGNORE_PATH, `${dir}/.npmignore`),
-      readFile(`${dir}/.USAGE.md`, 'utf8')
-        .then(content =>
-          writeFile(
-            `${dir}/README.md`,
-            generateReadme({
-              pkg,
-              usage: content.trim(),
-            })
-          )
-        )
-        .catch(error => {
-          if (error.code !== 'ENOENT') {
-            console.error('Error while handling README', error)
-          }
-        }),
+      usageToReadme(`${dir}/.USAGE.md`).catch(error => {
+        if (error.code !== 'ENOENT') {
+          console.error('Error while handling README', error)
+        }
+      }),
       useBabel ? forceRelativeSymlink(BABEL_ESLINTRC_PATH, `${dir}/.eslintrc.js`) : unlink(`${dir}/.eslintrc.js`),
       writeFile(`${dir}/package.json`, JSON.stringify(pkg, null, 2) + '\n'),
       useBabel || unlink(`${dir}/.babelrc.js`),

scripts/usage-to-readme.js

@@ -0,0 +1,46 @@
+#!/usr/bin/env node
+
+'use strict'
+
+const { compile } = require('handlebars')
+const { dirname, join } = require('node:path')
+const { readFile, writeFile } = require('node:fs/promises')
+const { execFile } = require('node:child_process')
+
+const generateReadme = readFile(join(__dirname, 'README.md.tpl'), 'utf8').then(compile)
+
+async function usageToReadme(...args) {
+  const gitAdd = args[0] === '--git-add'
+  if (gitAdd) {
+    args.shift()
+  }
+
+  const usagePath = args[0]
+  const dir = dirname(usagePath)
+
+  const [usage, pkg] = await Promise.all([
+    readFile(usagePath, 'utf8'),
+    readFile(join(dir, 'package.json')).then(JSON.parse),
+  ])
+
+  const readmePath = join(dir, 'README.md')
+  await writeFile(readmePath, (await generateReadme)({ pkg, usage: usage.trim() }))
+
+  if (gitAdd) {
+    await new Promise((resolve, reject) => {
+      execFile('git', ['add', '--', readmePath])
+        .on('error', reject)
+        .on('exit', code => {
+          if (code !== 0) {
+            reject(new Error('command exited with non-zero status code: ' + code))
+          }
+        })
+    })
+  }
+}
+
+if (module.parent !== null) {
+  module.exports = usageToReadme
+} else {
+  usageToReadme(...process.argv.slice(2))
+}