From 2df5957f9b462fa73d3b950e319683cb685afecd Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Tue, 23 Sep 2014 15:41:44 -0600
Subject: [PATCH] Restore commands after each spec

This commit adds the ability to get and restore snapshots of command
listeners. Whatever commands are installed before specs begin are
preserved, but commands added during specs are always cleared away.
---
 spec/command-registry-spec.coffee | 28 ++++++++++++++++++++++++++++
 spec/spec-helper.coffee           |  2 ++
 src/command-registry.coffee       | 11 +++++++++++
 3 files changed, 41 insertions(+)

diff --git a/spec/command-registry-spec.coffee b/spec/command-registry-spec.coffee
index 98c480375..03c0b4717 100644
--- a/spec/command-registry-spec.coffee
+++ b/spec/command-registry-spec.coffee
@@ -145,3 +145,31 @@ describe "CommandRegistry", ->
       expect(registry.dispatch(grandchild, 'command')).toBe true
       expect(registry.dispatch(grandchild, 'bogus')).toBe false
       expect(registry.dispatch(parent, 'command')).toBe false
+
+  describe "::getSnapshot and ::restoreSnapshot", ->
+    it "removes all command handlers except for those in the snapshot", ->
+      registry.add '.parent', 'namespace:command-1', ->
+      registry.add '.child', 'namespace:command-2', ->
+      snapshot = registry.getSnapshot()
+      registry.add '.grandchild', 'namespace:command-3', ->
+
+      expect(registry.findCommands(target: grandchild)[0..2]).toEqual [
+        {name: 'namespace:command-3', displayName: 'Namespace: Command 3'}
+        {name: 'namespace:command-2', displayName: 'Namespace: Command 2'}
+        {name: 'namespace:command-1', displayName: 'Namespace: Command 1'}
+      ]
+
+      registry.restoreSnapshot(snapshot)
+
+      expect(registry.findCommands(target: grandchild)[0..1]).toEqual [
+        {name: 'namespace:command-2', displayName: 'Namespace: Command 2'}
+        {name: 'namespace:command-1', displayName: 'Namespace: Command 1'}
+      ]
+
+      registry.add '.grandchild', 'namespace:command-3', ->
+      registry.restoreSnapshot(snapshot)
+
+      expect(registry.findCommands(target: grandchild)[0..1]).toEqual [
+        {name: 'namespace:command-2', displayName: 'Namespace: Command 2'}
+        {name: 'namespace:command-1', displayName: 'Namespace: Command 1'}
+      ]
diff --git a/spec/spec-helper.coffee b/spec/spec-helper.coffee
index c4f39bbb7..a5a31ac4b 100644
--- a/spec/spec-helper.coffee
+++ b/spec/spec-helper.coffee
@@ -27,6 +27,7 @@ fixturePackagesPath = path.resolve(__dirname, './fixtures/packages')
 atom.packages.packageDirPaths.unshift(fixturePackagesPath)
 atom.keymaps.loadBundledKeymaps()
 keyBindingsToRestore = atom.keymaps.getKeyBindings()
+commandsToRestore = atom.commands.getSnapshot()
 
 $(window).on 'core:close', -> window.close()
 $(window).on 'beforeunload', ->
@@ -65,6 +66,7 @@ beforeEach ->
   atom.workspace = new Workspace()
   atom.keymaps.keyBindings = _.clone(keyBindingsToRestore)
   atom.commands.setRootNode(document.body)
+  atom.commands.restoreSnapshot(commandsToRestore)
 
   window.resetTimeouts()
   atom.packages.packageStates = {}
diff --git a/src/command-registry.coffee b/src/command-registry.coffee
index 11dec2dca..fb05341f8 100644
--- a/src/command-registry.coffee
+++ b/src/command-registry.coffee
@@ -46,6 +46,8 @@ class CommandRegistry
   constructor: (@rootNode) ->
     @listenersByCommandName = {}
 
+  getRootNode: -> @rootNode
+
   setRootNode: (newRootNode) ->
     oldRootNode = @rootNode
     @rootNode = newRootNode
@@ -149,6 +151,15 @@ class CommandRegistry
     eventWithTarget = Object.create(event, target: value: target)
     @handleCommandEvent(eventWithTarget)
 
+  getSnapshot: ->
+    _.deepClone(@listenersByCommandName)
+
+  restoreSnapshot: (snapshot) ->
+    rootNode = @getRootNode()
+    @setRootNode(null) # clear listeners for current commands
+    @listenersByCommandName = _.deepClone(snapshot)
+    @setRootNode(rootNode) # restore listeners for commands in snapshot
+
   handleCommandEvent: (event) =>
     propagationStopped = false
     immediatePropagationStopped = false