Move configuration to module

Summary:
Moves the JSON config access to one module instead of
ad-hoc de-serialising the object all over the place.
This also adds a type for it so we hopefully won't typo things that easily.

Reviewed By: danielbuechele

Differential Revision: D13956612

fbshipit-source-id: 48098deafedf18cc86c8802a3c40fba9394b8262

src/chrome/ScreenCaptureButtons.js

@@ -17,16 +17,13 @@ import {exec, spawn} from 'child_process';
 import {remote} from 'electron';
 import path from 'path';
 import {reportPlatformFailures} from '../utils/metrics';
-
-let CAPTURE_LOCATION = remote.app.getPath('desktop');
-try {
-  CAPTURE_LOCATION = expandTilde(
-    JSON.parse(window.process.env.CONFIG).screenCapturePath || CAPTURE_LOCATION,
-  );
-} catch (e) {}
-
+import config from '../utils/processConfig';
 import type BaseDevice from '../devices/BaseDevice';
 
+const CAPTURE_LOCATION = expandTilde(
+  config().screenCapturePath || remote.app.getPath('desktop'),
+);
+
 type PullTransfer = any;
 
 type Props = {|

src/dispatcher/plugins.js

@@ -24,6 +24,7 @@ import GK from '../fb-stubs/GK';
 import {FlipperBasePlugin} from '../plugin.js';
 import {setupMenuBar} from '../MenuBar.js';
 import path from 'path';
+import {default as config} from '../utils/processConfig.js';
 
 export type PluginDefinition = {
   name: string,
@@ -129,11 +130,7 @@ export const checkDisabled = (disabledPlugins: Array<PluginDefinition>) => (
 ): boolean => {
   let disabledList: Set<string> = new Set();
   try {
-    disabledList = new Set(
-      // $FlowFixMe process.env not defined in electron API spec
-      JSON.parse(remote?.process.env.CONFIG || process.env.CONFIG || '{}')
-        .disabledPlugins || [],
-    );
+    disabledList = config().disabledPlugins;
   } catch (e) {
     console.error(e);
   }

src/utils/__tests__/processConfig.node.js

@@ -0,0 +1,42 @@
+/**
+ * Copyright 2018-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ */
+
+import {default as config, resetConfigForTesting} from '../processConfig.js';
+
+afterEach(() => {
+  resetConfigForTesting();
+});
+
+test('config is decoded from env', () => {
+  process.env.CONFIG = JSON.stringify({
+    disabledPlugins: ['pluginA', 'pluginB', 'pluginC'],
+    pluginPaths: ['/a/path', 'b/path'],
+    lastWindowPosition: {x: 4, y: 8, width: 15, height: 16},
+    updaterEnabled: false,
+    screenCapturePath: '/my/screenshot/path',
+  });
+
+  expect(config()).toEqual({
+    disabledPlugins: new Set(['pluginA', 'pluginB', 'pluginC']),
+    pluginPaths: ['/a/path', 'b/path'],
+    lastWindowPosition: {x: 4, y: 8, width: 15, height: 16},
+    updaterEnabled: false,
+    screenCapturePath: '/my/screenshot/path',
+  });
+});
+
+test('config is decoded from env with defaults', () => {
+  process.env.CONFIG = '{}';
+
+  expect(config()).toEqual({
+    disabledPlugins: new Set([]),
+    pluginPaths: [],
+    lastWindowPosition: undefined,
+    updaterEnabled: true,
+    screenCapturePath: undefined,
+  });
+});

src/utils/processConfig.js

@@ -0,0 +1,40 @@
+/**
+ * Copyright 2018-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ */
+
+import {remote} from 'electron';
+
+export type ProcessConfig = {|
+  disabledPlugins: Set<string>,
+  pluginPaths: Array<string>,
+  lastWindowPosition: ?{x: number, y: number, width: number, height: number},
+  screenCapturePath: ?string,
+  updaterEnabled: boolean,
+|};
+
+let configObj = null;
+export default function config(): ProcessConfig {
+  if (configObj === null) {
+    const json = JSON.parse(
+      // $FlowFixMe: process.env not in type defs
+      remote?.process.env.CONFIG || process.env.CONFIG || '{}',
+    );
+    configObj = {
+      disabledPlugins: new Set(json.disabledPlugins || []),
+      pluginPaths: json.pluginPaths || [],
+      lastWindowPosition: json.lastWindowPosition,
+      updaterEnabled:
+        typeof json.updaterEnabled === 'boolean' ? json.updaterEnabled : true,
+      screenCapturePath: json.screenCapturePath,
+    };
+  }
+
+  return configObj;
+}
+
+export function resetConfigForTesting() {
+  configObj = null;
+}