Specify ATOM_HOME when starting Atom in integration test

Otherwise, tests may fail because the Welcome pane may appear,
depending on the content of `~/.atom/config.cson`

spec/integration/fixtures/atom-home/config.cson

@@ -0,0 +1,5 @@
+"*":
+  welcome:
+    showOnStartup: false
+  "exception-reporting":
+    userId: "7c0a3c52-795c-5e20-5323-64efcf91f212"

spec/integration/helpers/atom-launcher.sh

@@ -1,12 +1,15 @@
 #!/bin/bash
 
 # This script wraps the `Atom` binary, allowing the `chromedriver` server to
-# execute it with positional arguments. `chromedriver` only allows 'switches'
-# to be specified when starting a browser, not positional arguments, so this
-# script accepts two special switches:
+# execute it with positional arguments and environment variables. `chromedriver`
+# only allows 'switches' to be specified when starting a browser, not positional
+# arguments, so this script accepts the following special switches:
 #
-# * `atom-path` The path to the `Atom` binary
-# * `atom-args` A space-separated list of positional arguments to pass to Atom.
+# * `atom-path`: The path to the `Atom` binary.
+# * `atom-arg`:  A positional argument to pass to Atom. This flag can be specified
+#                multiple times.
+# * `atom-env`:  A key=value environment variable to set for Atom. This flag can
+#                be specified multiple times.
 #
 # Any other switches will be passed through to `Atom`.
 
@@ -20,11 +23,12 @@ for arg in "$@"; do
       atom_path="${arg#*=}"
       ;;
 
-    --atom-args=*)
-      atom_args_string="${arg#*=}"
-      for atom_arg in $atom_args_string; do
-        atom_args+=($atom_arg)
-      done
+    --atom-arg=*)
+      atom_args+=(${arg#*=})
+      ;;
+
+    --atom-env=*)
+      export ${arg#*=}
       ;;
 
     *)
@@ -33,4 +37,7 @@ for arg in "$@"; do
   esac
 done
 
-exec $atom_path "${atom_switches[@]}" "${atom_args[@]}"
+echo "Launching Atom" >&2
+echo ${atom_path} ${atom_args[@]} ${atom_switches[@]} >&2
+
+exec ${atom_path} ${atom_args[@]} ${atom_switches[@]}

spec/integration/helpers/start-atom.coffee

@@ -2,6 +2,7 @@ os = require "os"
 path = require "path"
 temp = require("temp").track()
 remote = require "remote"
+{map, extend} = require "underscore-plus"
 {spawn, spawnSync} = require "child_process"
 webdriverio = require "../../../build/node_modules/webdriverio"
 async = require "async"
@@ -39,7 +40,7 @@ module.exports =
     runs -> chromedriver.kill()
 
   # Start Atom using chromedriver.
-  startAtom: (args...) ->
+  startAtom: (args, env={}) ->
     webdriverio.remote(
       host: 'localhost'
       port: ChromedriverPort
@@ -49,12 +50,13 @@ module.exports =
           binary: AtomLauncherPath
           args: [
             "atom-path=#{AtomPath}"
-            "atom-args=#{args.join(" ")}"
             "dev"
             "safe"
             "user-data-dir=#{temp.mkdirSync('integration-spec-')}"
             "socket-path=#{SocketPath}"
-          ])
+          ]
+          .concat(map args, (arg) -> "atom-arg=#{arg}")
+          .concat(map env, (value, key) -> "atom-env=#{key}=#{value}"))
       .init()
       .addCommand "waitForCondition", (conditionFn, timeout, cb) ->
         timedOut = succeeded = false
@@ -78,9 +80,9 @@ module.exports =
 
   # Once one `Atom` window is open, subsequent invocations of `Atom` will exit
   # immediately.
-  startAnotherAtom: (args...) ->
+  startAnotherAtom: (args, env={}) ->
     spawnSync(AtomPath, args.concat([
-      "--dev",
-      "--safe",
+      "--dev"
+      "--safe"
       "--socket-path=#{SocketPath}"
-    ]))
+    ]), env: extend({}, process.env, env))

spec/integration/startup-spec.coffee

@@ -6,6 +6,7 @@ return unless process.env.ATOM_INTEGRATION_TESTS_ENABLED
 fs = require "fs"
 path = require "path"
 temp = require("temp").track()
+AtomHome = path.join(__dirname, "fixtures", "atom-home")
 {startAtom, startAnotherAtom, driverTest} = require("./helpers/start-atom")
 
 describe "Starting Atom", ->
@@ -24,7 +25,7 @@ describe "Starting Atom", ->
       driverTest ->
 
         # Opening a new file creates one window with one empty text editor.
-        startAtom(path.join(tempDirPath, "new-file"))
+        startAtom([path.join(tempDirPath, "new-file")], ATOM_HOME: AtomHome)
           .waitForExist("atom-text-editor", 5000)
           .then((exists) -> expect(exists).toBe true)
           .windowHandles()
@@ -42,7 +43,7 @@ describe "Starting Atom", ->
 
           # Opening an existing file in the same directory reuses the window and
           # adds a new tab for the file.
-          .call(-> startAnotherAtom(tempFilePath))
+          .call(-> startAnotherAtom([tempFilePath], ATOM_HOME: AtomHome))
           .waitForCondition(
             (-> @execute((-> atom.workspace.getActivePane().getItems().length)).then ({value}) -> value is 2),
             5000)
@@ -52,7 +53,7 @@ describe "Starting Atom", ->
 
           # Opening a different directory creates a second window with no
           # tabs open.
-          .call(-> startAnotherAtom(temp.mkdirSync("another-empty-dir")))
+          .call(-> startAnotherAtom([temp.mkdirSync("another-empty-dir")], ATOM_HOME: AtomHome))
           .waitForCondition(
             (-> @windowHandles().then(({value}) -> value.length is 2)),
             5000)