Make react-native link play nicely with CocoaPods-based iOS projects.

Summary:
The core React Native codebase already has full support for CocoaPods. However, `react-native link` doesn’t play nicely with CocoaPods, so installing third-party libs from the RN ecosystem is really hard.

This change will allow to link projects that contains its own `.podspec` file to CocoaPods-based projects. In case `link` detect `Podfile` in `iOS` directory, it will look for related `.podspec` file in linked project directory, and add it to `Podfile`. If `Podfile` and `.podspec` files are not present, it will fall back to previous implementation.

**Test Plan**
1. Build a React Native project where the iOS part uses CocoaPods to manage its dependencies. The most common scenario here is to have React Native be a Pod dependency, among others.
2. Install a RN-related library, that contains `.podspec` file, with `react-native link` (as an example it could be: [react-native-maps](https://github.com/airbnb/react-native-maps)
3. Building the resulting iOS workspace should succeed (and there should be new entry in `Podfile`)
Closes #15460

Differential Revision: D6078649

Pulled By: hramos

fbshipit-source-id: 9651085875892fd66299563ca0e42fb2bcc00825

Author: mironiasty

docs/LinkingLibraries.md

@@ -35,8 +35,8 @@ Install a library with native dependencies:
 $ npm install <library-with-native-dependencies> --save
 ```
 
-**Note:** _`--save` or `--save-dev` flag is very important for this step. React Native will link
-your libs based on `dependencies` and `devDependencies` in your `package.json` file._
+> ***Note:*** `--save` or `--save-dev` flag is very important for this step. React Native will link
+your libs based on `dependencies` and `devDependencies` in your `package.json` file.
 
 #### Step 2
 
@@ -47,6 +47,10 @@ $ react-native link
 
 Done! All libraries with native dependencies should be successfully linked to your iOS/Android project.
 
+> ***Note:*** If your iOS project is using CocoaPods (contains `Podfile`) and linked library has `podspec` file,
+then `react-native link` will link library using Podfile. To support non-trivial Podfiles 
+add `# Add new pods below this line` comment to places where you expect pods to be added.
+
 ### Manual linking
 
 #### Step 1

local-cli/core/__fixtures__/ios.js

@@ -5,10 +5,15 @@ exports.valid = {
   'demoProject.xcodeproj': {
     'project.pbxproj': fs.readFileSync(path.join(__dirname, './files/project.pbxproj')),
   },
+  'TestPod.podspec': 'empty'
 };
 
 exports.validTestName = {
   'MyTestProject.xcodeproj': {
     'project.pbxproj': fs.readFileSync(path.join(__dirname, './files/project.pbxproj')),
   },
 };
+
+exports.pod = {
+  'TestPod.podspec': 'empty'
+};

local-cli/core/__fixtures__/projects.js

@@ -4,6 +4,7 @@ const ios = require('./ios');
 const flat = {
   android: android.valid,
   ios: ios.valid,
+  Podfile: 'empty'
 };
 
 const nested = {
@@ -19,4 +20,9 @@ const withExamples = {
   android: android.valid,
 };
 
-module.exports = { flat, nested, withExamples };
+const withPods = {
+  Podfile: 'content',
+  ios: ios.pod
+};
+
+module.exports = { flat, nested, withExamples, withPods };

local-cli/core/__tests__/ios/findPodfilePath.spec.js

@@ -0,0 +1,20 @@
+'use strict';
+
+jest.mock('fs');
+
+const findPodfilePath = require('../../ios/findPodfilePath');
+const fs = require('fs');
+const projects = require('../../__fixtures__/projects');
+const ios = require('../../__fixtures__/ios');
+
+describe('ios::findPodfilePath', () => {
+  it('returns null if there is no Podfile', () => {
+    fs.__setMockFilesystem(ios.valid);
+    expect(findPodfilePath('')).toBeNull();
+  });
+
+  it('returns Podfile path if it exists', () => {
+    fs.__setMockFilesystem(projects.withPods);
+    expect(findPodfilePath('/ios')).toContain('Podfile');
+  });
+});

local-cli/core/__tests__/ios/findPodspecName.spec.js

@@ -0,0 +1,44 @@
+'use strict';
+
+jest.mock('fs');
+
+const findPodspecName = require('../../ios/findPodspecName');
+const fs = require('fs');
+const projects = require('../../__fixtures__/projects');
+const ios = require('../../__fixtures__/ios');
+
+describe('ios::findPodspecName', () => {
+  it('returns null if there is not podspec file', () => {
+    fs.__setMockFilesystem(projects.flat);
+    expect(findPodspecName('')).toBeNull();
+  });
+
+  it('returns podspec name if only one exists', () => {
+    fs.__setMockFilesystem(ios.pod);
+    expect(findPodspecName('/')).toBe('TestPod');
+  });
+
+  it('returns podspec name that match packet directory', () => {
+    fs.__setMockFilesystem({
+      user: {
+        PacketName: {
+          'Another.podspec': 'empty',
+          'PacketName.podspec': 'empty'
+        }
+      }
+    });
+    expect(findPodspecName('/user/PacketName')).toBe('PacketName');
+  });
+
+  it('returns first podspec name if not match in directory', () => {
+    fs.__setMockFilesystem({
+      user: {
+        packet: {
+          'Another.podspec': 'empty',
+          'PacketName.podspec': 'empty'
+        }
+      }
+    });
+    expect(findPodspecName('/user/packet')).toBe('Another');
+  });
+});

local-cli/core/ios/findPodfilePath.js

@@ -0,0 +1,11 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+
+module.exports = function findPodfilePath(projectFolder) {
+  const podFilePath = path.join(projectFolder, '..', 'Podfile');
+  const podFileExists = fs.existsSync(podFilePath);
+
+  return podFileExists ? podFilePath : null;
+};

local-cli/core/ios/findPodspecName.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const glob = require('glob');
+const path = require('path');
+
+module.exports = function findPodspecName(folder) {
+  const podspecs = glob.sync('*.podspec', { cwd: folder });
+  let podspecFile = null;
+  if (podspecs.length === 0) {
+    return null;
+  }
+  else if (podspecs.length === 1) {
+    podspecFile = podspecs[0];
+  }
+  else {
+    const folderParts = folder.split(path.sep);
+    const currentFolder = folderParts[folderParts.length - 1];
+    const toSelect = podspecs.indexOf(currentFolder + '.podspec');
+    if (toSelect === -1) {
+      podspecFile = podspecs[0];
+    }
+    else {
+      podspecFile = podspecs[toSelect];
+    }
+  }
+
+  return podspecFile.replace('.podspec', '');
+};

local-cli/core/ios/index.js

@@ -9,6 +9,8 @@
 'use strict';
 
 const findProject = require('./findProject');
+const findPodfilePath = require('./findPodfilePath');
+const findPodspecName = require('./findPodspecName');
 const path = require('path');
 
 /**
@@ -44,6 +46,8 @@ exports.projectConfig = function projectConfigIOS(folder, userConfig) {
     sourceDir: path.dirname(projectPath),
     folder: folder,
     pbxprojPath: path.join(projectPath, 'project.pbxproj'),
+    podfile: findPodfilePath(projectPath),
+    podspec: findPodspecName(folder),
     projectPath: projectPath,
     projectName: path.basename(projectPath),
     libraryFolder: userConfig.libraryFolder || 'Libraries',

local-cli/link/__fixtures__/pods/PodfileSimple

@@ -0,0 +1,8 @@
+source 'https://github.com/CocoaPods/Specs.git'
+platform :ios, '9.0'
+
+target 'Testing' do
+  pod 'TestPod', '~> 3.1'
+  
+  # test should point to this line
+end

local-cli/link/__fixtures__/pods/PodfileWithFunction

@@ -0,0 +1,30 @@
+source 'https://github.com/CocoaPods/Specs.git'
+platform :ios, '9.0'
+
+target 'none' do
+  pod 'React',
+    :path => "../node_modules/react-native",
+    :subspecs => [
+      "Core",
+      "ART",
+      "RCTActionSheet",
+      "RCTAnimation",
+      "RCTCameraRoll",
+      "RCTGeolocation",
+      "RCTImage",
+      "RCTNetwork",
+      "RCTText",
+      "RCTVibration",
+      "RCTWebSocket",
+      "DevSupport",
+      "BatchedBridge"
+    ]
+
+  pod 'Yoga',
+    :path => "../node_modules/react-native/ReactCommon/yoga" 
+  
+  # test should point to this line
+  post_install do |installer|
+      
+  end
+end