Move the code related to plugin loading / installation to "flipper-plugin-lib"

Summary:
Sorry for so long diff, but actually there are no functional changes, just refactoring to make further changes of Plugin Manager easier to understand.

I've de-coupled the code related to plugin management from UI code and moved it from PluginInstaller UI component (which will be replaced soon by new UI) to "flipper-plugin-lib".  So pretty much everything related to plugin discovery and installation now consolidated in this package.

Additionally, this refactoring enables re-using of plugin management code in "flipper-pkg", e.g. to create CLI command for plugin installation from NPM, e.g.: `flipper-pkg install flipper-plugin-reactotron`.

Reviewed By: passy

Differential Revision: D23679346

fbshipit-source-id: 82e7b9de9afa08c508c1b228c2038b4ba423571c

desktop/plugin-lib/src/__tests__/getUpdatablePlugins.node.ts

@@ -0,0 +1,131 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+jest.mock('../getInstalledPlugins');
+jest.mock('../getNpmHostedPlugins');
+
+import {getUpdatablePlugins} from '../getUpdatablePlugins';
+import {
+  getNpmHostedPlugins,
+  NpmPackageDescriptor,
+} from '../getNpmHostedPlugins';
+import type {InstalledPluginDetails} from '../getInstalledPlugins';
+import {getInstalledPlugins} from '../getInstalledPlugins';
+import {mocked} from 'ts-jest/utils';
+import type {Package} from 'npm-api';
+
+jest.mock('npm-api', () => {
+  return jest.fn().mockImplementation(() => {
+    return {
+      repo: jest.fn().mockImplementation((name: string) => {
+        let pkg: Package | undefined;
+        if (name === 'flipper-plugin-hello') {
+          pkg = {
+            $schema: 'https://fbflipper.com/schemas/plugin-package/v2.json',
+            name: 'flipper-plugin-hello',
+            title: 'Hello',
+            version: '0.1.0',
+            main: 'dist/bundle.js',
+            flipperBundlerEntry: 'src/index.js',
+            description: 'World?',
+          };
+        } else if (name === 'flipper-plugin-world') {
+          pkg = {
+            $schema: 'https://fbflipper.com/schemas/plugin-package/v2.json',
+            name: 'flipper-plugin-world',
+            title: 'World',
+            version: '0.3.0',
+            main: 'dist/bundle.js',
+            flipperBundlerEntry: 'src/index.js',
+            description: 'World?',
+          };
+        }
+        return {
+          package: jest.fn().mockImplementation(() => Promise.resolve(pkg)),
+        };
+      }),
+    };
+  });
+});
+
+const installedPlugins: InstalledPluginDetails[] = [
+  {
+    name: 'flipper-plugin-hello',
+    entry: './test/index.js',
+    version: '0.1.0',
+    specVersion: 2,
+    main: 'dist/bundle.js',
+    dir: '/Users/mock/.flipper/thirdparty/flipper-plugin-sample1',
+    source: 'src/index.js',
+    id: 'Hello',
+    title: 'Hello',
+    description: 'World?',
+    isDefault: false,
+    installationStatus: 'installed',
+  },
+  {
+    name: 'flipper-plugin-world',
+    entry: './test/index.js',
+    version: '0.2.0',
+    specVersion: 2,
+    main: 'dist/bundle.js',
+    dir: '/Users/mock/.flipper/thirdparty/flipper-plugin-sample2',
+    source: 'src/index.js',
+    id: 'World',
+    title: 'World',
+    description: 'Hello?',
+    isDefault: false,
+    installationStatus: 'pending',
+  },
+];
+
+const updates: NpmPackageDescriptor[] = [
+  {name: 'flipper-plugin-hello', version: '0.1.0'},
+  {name: 'flipper-plugin-world', version: '0.3.0'},
+];
+
+test('annotatePluginsWithUpdates', async () => {
+  const getInstalledPluginsMock = mocked(getInstalledPlugins);
+  getInstalledPluginsMock.mockReturnValue(Promise.resolve(installedPlugins));
+
+  const getNpmHostedPluginsMock = mocked(getNpmHostedPlugins);
+  getNpmHostedPluginsMock.mockReturnValue(Promise.resolve(updates));
+
+  const res = await getUpdatablePlugins();
+
+  expect(res.length).toBe(2);
+  expect({
+    name: res[0].name,
+    version: res[0].version,
+    updateStatus: res[0].updateStatus,
+  }).toMatchInlineSnapshot(`
+    Object {
+      "name": "flipper-plugin-hello",
+      "updateStatus": Object {
+        "kind": "up-to-date",
+      },
+      "version": "0.1.0",
+    }
+  `);
+
+  expect({
+    name: res[1].name,
+    version: res[1].version,
+    updateStatus: res[1].updateStatus,
+  }).toMatchInlineSnapshot(`
+    Object {
+      "name": "flipper-plugin-world",
+      "updateStatus": Object {
+        "kind": "update-available",
+        "version": "0.3.0",
+      },
+      "version": "0.3.0",
+    }
+  `);
+});