feat(postinstall): automatically add itself as plugin on install, close

#14

README.md

@@ -80,7 +80,7 @@ See [inquirer](https://www.npmjs.com/package/inquirer) for details.
 
 This module can function as [analyzeCommits plugin](https://github.com/semantic-release/semantic-release#analyzecommits)
 for [semantic-release](https://github.com/semantic-release/semantic-release).
-Just add to the `package.json`
+Just add to the `package.json` (during install this will be done automatically)
 
 ```json
 {

package.json

@@ -8,13 +8,15 @@
   "version": "0.0.0-development",
   "scripts": {
     "ban": "node node_modules/.bin/ban",
+    "deps": "deps-ok && dependency-check --no-dev .  --entry src/postinstall.js",
     "test": "rocha src/*-spec.js",
     "lint": "standard --verbose --fix bin/*.js src/*.js",
     "commit": "commit-wizard",
     "semantic-release": "semantic-release pre && npm publish && semantic-release post",
     "size": "t=\"$(npm pack .)\"; wc -c \"${t}\"; tar tvf \"${t}\"; rm \"${t}\";",
     "wizard": "node bin/simple-wizard.js",
-    "issues": "git-issues"
+    "issues": "git-issues",
+    "postinstall": "node src/postinstall.js"
   },
   "repository": {
     "type": "git",
@@ -41,6 +43,8 @@
   "homepage": "https://github.com/bahmutov/simple-commit-message#readme",
   "devDependencies": {
     "ban-sensitive-files": "1.9.0",
+    "dependency-check": "2.9.1",
+    "deps-ok": "1.2.0",
     "git-issues": "1.3.1",
     "github-post-release": "1.12.1",
     "next-update-travis": "1.5.2",
@@ -67,6 +71,7 @@
     }
   },
   "dependencies": {
+    "am-i-a-dependency": "1.0.0",
     "check-more-types": "2.24.0",
     "debug": "2.6.8",
     "ggit": "1.22.1",

src/postinstall.js

@@ -0,0 +1,54 @@
+#!/usr/bin/env node
+
+'use strict'
+
+const debug = require('debug')('simple')
+const amIaDependency = require('am-i-a-dependency')
+const isForced = process.argv.some(a => a === '--force')
+
+if (!amIaDependency() && !isForced) {
+  // top level install (we are running `npm i` in this project)
+  debug('we are installing own dependencies')
+  process.exit(0)
+}
+
+debug('installing this module as a dependency')
+
+const path = require('path')
+const fs = require('fs')
+
+function clientPackageJsonFilename () {
+  return path.join(process.cwd(), '..', '..', 'package.json')
+}
+
+function alreadyInstalled () {
+  const filename = clientPackageJsonFilename()
+  const pkg = require(filename)
+  if (!pkg.release) {
+    return false
+  }
+  if (!pkg.release.analyzeCommits) {
+    return false
+  }
+  return true
+}
+
+function addPlugin () {
+  const filename = clientPackageJsonFilename()
+  const pkg = require(filename)
+  if (!pkg.release) {
+    pkg.release = {}
+  }
+  pkg.release.analyzeCommits = 'simple-commit-message'
+  const text = JSON.stringify(pkg, null, 2) + '\n'
+  fs.writeFileSync(filename, text, 'utf8')
+  console.log('✅  set generate notes plugin in', filename)
+}
+
+if (alreadyInstalled()) {
+  debug('plugin analyzeCommits already set')
+  process.exit(0)
+}
+
+console.log('⚠️  Installing release analyzeCommits plugin simple-commit-message')
+addPlugin()