Config::restoreDefaults handles scopes

spec/config-spec.coffee

@@ -153,6 +153,26 @@ describe "Config", ->
       atom.config.restoreDefault('a.c')
       expect(atom.config.get('a.c')).toBeUndefined()
 
+    describe "when scoped settings are used", ->
+      it "restores the global default when no scoped default set", ->
+        atom.config.setDefaults("foo", bar: baz: 10)
+        atom.config.set('.source.coffee', 'foo.bar.baz', 55)
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.baz')).toBe 55
+
+        atom.config.restoreDefault('.source.coffee', 'foo.bar.baz')
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.baz')).toBe 10
+
+      it "restores the scoped default when a scoped default is set", ->
+        atom.config.setDefaults("foo", bar: baz: 10)
+        atom.config.addScopedSettings("default", ".source.coffee", foo: bar: baz: 42)
+        atom.config.set('.source.coffee', 'foo.bar.baz', 55)
+        atom.config.set('.source.coffee', 'foo.bar.ok', 100)
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.baz')).toBe 55
+
+        atom.config.restoreDefault('.source.coffee', 'foo.bar.baz')
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.baz')).toBe 42
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.ok')).toBe 100
+
   describe ".pushAtKeyPath(keyPath, value)", ->
     it "pushes the given value to the array at the key path and updates observers", ->
       atom.config.set("foo.bar.baz", ["a"])

src/config.coffee

@@ -519,9 +519,20 @@ class Config
   # * `keyPath` The {String} name of the key.
   #
   # Returns the new value.
-  restoreDefault: (keyPath) ->
-    @set(keyPath, _.valueForKeyPath(@defaultSettings, keyPath))
-    @get(keyPath)
+  restoreDefault: (scopeSelector, keyPath) ->
+    if arguments.length == 1
+      keyPath = scopeSelector
+      scopeSelector = null
+
+    if scopeSelector?
+      settings = @scopedSettingsStore.propertiesForSourceAndSelector('user-config', scopeSelector)
+      @scopedSettingsStore.removePropertiesForSourceAndSelector('user-config', scopeSelector)
+      _.setValueForKeyPath(settings, keyPath, undefined)
+      @addScopedSettings('user-config', scopeSelector, settings)
+      @getDefault(scopeSelector, keyPath)
+    else
+      @set(keyPath, _.valueForKeyPath(@defaultSettings, keyPath))
+      @get(keyPath)
 
   # Extended: Get the global default value of the key path. _Please note_ that in most
   # cases calling this is not necessary! {::get} returns the default value when