Merge pull request #4194 from atom/bo-fix-scoped-config-default

Fix resetting scoped config defaults

spec/config-spec.coffee

@@ -195,6 +195,52 @@ describe "Config", ->
         atom.config.restoreDefault('.source.coffee', 'foo.bar.baz')
         expect(atom.config.save.callCount).toBe 1
 
+      it "does not call ::save or add a scoped property when no value has been set", ->
+        # see https://github.com/atom/atom/issues/4175
+        atom.config.setDefaults("foo", bar: baz: 10)
+        atom.config.restoreDefault('.source.coffee', 'foo.bar.baz')
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.baz')).toBe 10
+
+        expect(atom.config.save).not.toHaveBeenCalled()
+
+        scopedProperties = atom.config.scopedSettingsStore.propertiesForSource('user-config')
+        expect(scopedProperties['.coffee.source']).toBeUndefined()
+
+      it "removes the scoped value when it was the only set value on the object", ->
+        spyOn(CSON, 'writeFileSync')
+        jasmine.unspy atom.config, 'save'
+
+        atom.config.setDefaults("foo", bar: baz: 10)
+        atom.config.set('.source.coffee', 'foo.bar.baz', 55)
+        atom.config.set('.source.coffee', 'foo.bar.zfoo', 20)
+        CSON.writeFileSync.reset()
+        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
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.zfoo')).toBe 20
+        expect(CSON.writeFileSync).toHaveBeenCalled()
+        properties = CSON.writeFileSync.mostRecentCall.args[1]
+        expect(properties['.coffee.source']).toEqual
+          foo:
+            bar:
+              zfoo: 20
+
+        CSON.writeFileSync.reset()
+        atom.config.restoreDefault('.source.coffee', 'foo.bar.zfoo')
+        expect(CSON.writeFileSync).toHaveBeenCalled()
+        properties = CSON.writeFileSync.mostRecentCall.args[1]
+        expect(properties['.coffee.source']).toBeUndefined()
+
+      it "does not call ::save when the value is already at the default", ->
+        atom.config.setDefaults("foo", bar: baz: 10)
+        atom.config.set('.source.coffee', 'foo.bar.baz', 55)
+        atom.config.save.reset()
+
+        atom.config.restoreDefault('.source.coffee', 'foo.bar.ok')
+        expect(atom.config.save).not.toHaveBeenCalled()
+        expect(atom.config.get(['.source.coffee'], 'foo.bar.baz')).toBe 55
+
   describe ".getSettings()", ->
     it "returns all settings including defaults", ->
       atom.config.setDefaults("foo", bar: baz: 10)

src/config.coffee

@@ -536,11 +536,13 @@ class Config
 
     if scopeSelector?
       settings = @scopedSettingsStore.propertiesForSourceAndSelector('user-config', scopeSelector)
-      @scopedSettingsStore.removePropertiesForSourceAndSelector('user-config', scopeSelector)
-      _.setValueForKeyPath(settings, keyPath, undefined)
-      @addScopedSettings('user-config', scopeSelector, settings, @usersScopedSettingPriority)
-      @save() unless @configFileHasErrors
-      @getDefault(scopeSelector, keyPath)
+      if _.valueForKeyPath(settings, keyPath)?
+        @scopedSettingsStore.removePropertiesForSourceAndSelector('user-config', scopeSelector)
+        _.setValueForKeyPath(settings, keyPath, undefined)
+        settings = withoutEmptyObjects(settings)
+        @addScopedSettings('user-config', scopeSelector, settings, @usersScopedSettingPriority) if settings?
+        @save() unless @configFileHasErrors
+        @getDefault(scopeSelector, keyPath)
     else
       @set(keyPath, _.valueForKeyPath(@defaultSettings, keyPath))
       @get(keyPath)
@@ -1046,3 +1048,15 @@ splitKeyPath = (keyPath) ->
       startIndex = i + 1
   keyPathArray.push keyPath.substr(startIndex, keyPath.length)
   keyPathArray
+
+withoutEmptyObjects = (object) ->
+  resultObject = undefined
+  if isPlainObject(object)
+    for key, value of object
+      newValue = withoutEmptyObjects(value)
+      if newValue?
+        resultObject ?= {}
+        resultObject[key] = newValue
+  else
+    resultObject = object
+  resultObject