Teach --dev to detect Atom repo in process.cwd()

src/main-process/get-dev-resource-path.js

@@ -0,0 +1,31 @@
+'use strict'
+
+const path = require('path')
+const fs = require('fs-plus')
+const CSON = require('season')
+const electron = require('electron')
+
+module.exports = function () {
+  const appResourcePath = path.dirname(path.dirname(__dirname))
+  const defaultRepositoryPath = path.join(electron.app.getPath('home'), 'github', 'atom')
+
+  if (process.env.ATOM_DEV_RESOURCE_PATH) {
+    return process.env.ATOM_DEV_RESOURCE_PATH
+  } else if (isAtomRepoPath(process.cwd())) {
+    return process.cwd()
+  } else if (fs.statSyncNoException(defaultRepositoryPath)) {
+    return defaultRepositoryPath
+  }
+
+  return appResourcePath
+}
+
+function isAtomRepoPath(repoPath) {
+  let packageJsonPath = path.join(repoPath, 'package.json')
+  if (fs.statSyncNoException(packageJsonPath)) {
+    let packageJson = CSON.readFileSync(packageJsonPath)
+    return packageJson.name === 'atom'
+  }
+
+  return false
+}

src/main-process/main.js

@@ -8,6 +8,7 @@ const electron = require('electron')
 const fs = require('fs')
 const path = require('path')
 const yargs = require('yargs')
+const getDevResourcePath = require('./get-dev-resource-path')
 
 const args =
   yargs(process.argv)
@@ -24,13 +25,7 @@ if (args.resourcePath) {
   const defaultRepositoryPath = path.join(electron.app.getPath('home'), 'github', 'atom')
 
   if (args.dev || args.test || args.benchmark || args.benchmarkTest) {
-    if (process.env.ATOM_DEV_RESOURCE_PATH) {
-      resourcePath = process.env.ATOM_DEV_RESOURCE_PATH
-    } else if (fs.statSyncNoException(defaultRepositoryPath)) {
-      resourcePath = defaultRepositoryPath
-    } else {
-      resourcePath = stableResourcePath
-    }
+    resourcePath = getDevResourcePath() || stableResourcePath
   } else {
     resourcePath = stableResourcePath
   }

src/main-process/parse-command-line.js

@@ -5,6 +5,7 @@ const yargs = require('yargs')
 const {app} = require('electron')
 const path = require('path')
 const fs = require('fs-plus')
+const getDevResourcePath = require('./get-dev-resource-path')
 
 module.exports = function parseCommandLine (processArgs) {
   const options = yargs(processArgs).wrap(yargs.terminalWidth())
@@ -119,7 +120,7 @@ module.exports = function parseCommandLine (processArgs) {
   let pathsToOpen = []
   let urlsToOpen = []
   let devMode = args['dev']
-  let devResourcePath = process.env.ATOM_DEV_RESOURCE_PATH || path.join(app.getPath('home'), 'github', 'atom')
+  let devResourcePath = getDevResourcePath
   let resourcePath = null
 
   for (const path of args._) {