ios: Start using CocoaPods again.

There was an attempt to use CocoaPods in aded466, 2017-03-19.

That was removed in 4096e71, 2017-07-18.

Some cleanup was done in 861744b, 2020-02-05.

To paraphrase Greg on zulip#3983:

CocoaPods is a tool for managing iOS libraries. Many people use it
in their React Native apps, but there some tricky bits that have
impeded universal adoption.

RN v0.60 signals a full embrace of the use of CocoaPods by making it
work more smoothly with RN. CocoaPods becomes required in v0.61.

So, use CocoaPods, writing a Podfile based on the example Podfile
given for react-native v0.59, at
https://github.com/facebook/react-native-website/blob/ded79d2cf4456d8b1a4f67c2cdc1391789e70617/docs/integration-with-existing-apps.md.
(That doc isn't live on the react-native docs website because of
facebook/react-native-website#1603.)

Originally, we were going to start using CocoaPods as part of the RN
v0.60 upgrade, but we have a fresh reason to want to use CocoaPods,
with its own deadline: zulip#3964, Apple auth. Someone has made a handy
Expo package to handle Apple auth, but we can't use Expo packages
without either fully committing to using the Expo SDK (a dramatic
step) or using a package called react-native-unimodules, which lets
you select individual Expo packages. react-native-unimodules
requires the use of CocoaPods.

Fixes: zulip#3983

.gitattributes

@@ -3,6 +3,7 @@
 # Suppress noisy generated files in diffs.
 yarn.lock -diff
 src/webview/js/generatedEs3.js -diff
+ios/Podfile.lock
 
 # The flow-typed files that aren't pure generated noise have names with at
 # least a major version number -- like `redux_v4.x.x.js`.

.gitignore

@@ -65,7 +65,7 @@ npm-debug.log
 # Test files
 /pirlo-cli
 
-# CocoaPods (not currently used)
+# CocoaPods
 /ios/Pods
 
 # Transifex, for a maintainer syncing translations up and down

ios/Podfile

@@ -0,0 +1,31 @@
+# This was the iOS Deployment Target (project > ZulipMobile > Info in Xcode)
+# as of 2020-03.
+platform :ios, '10.3'
+
+# This list will need to change for RN > v0.59. If you're changing it
+# for any other reason, first look at the official example Podfile at
+# https://github.com/facebook/react-native-website/blob/ded79d2cf/docs/integration-with-existing-apps.md#configuring-cocoapods-dependencies.
+target 'ZulipMobile' do
+  pod 'React', :path => '../node_modules/react-native', :subspecs => [
+    'Core',
+    'CxxBridge',
+    'DevSupport',
+    'RCTText',
+    'RCTNetwork',
+    'RCTWebSocket', # Needed for debugging
+    'RCTAnimation', # Needed for FlatList and animations running on native UI thread
+    # Add any other subspecs you want to use in your project
+  ]
+  pod 'yoga', :path => '../node_modules/react-native/ReactCommon/yoga'
+
+  # Third party deps podspec link
+  pod 'DoubleConversion', :podspec => '../node_modules/react-native/third-party-podspecs/DoubleConversion.podspec'
+  pod 'glog', :podspec => '../node_modules/react-native/third-party-podspecs/glog.podspec'
+  pod 'Folly', :podspec => '../node_modules/react-native/third-party-podspecs/Folly.podspec'
+
+  target 'ZulipMobileTests' do
+    inherit! :search_paths
+    # Pods for testing
+  end
+
+end

ios/Podfile.lock

@@ -0,0 +1,90 @@
+PODS:
+  - boost-for-react-native (1.63.0)
+  - DoubleConversion (1.1.6)
+  - Folly (2018.10.22.00):
+    - boost-for-react-native
+    - DoubleConversion
+    - glog
+  - glog (0.3.5)
+  - React/Core (0.59.10):
+    - yoga (= 0.59.10.React)
+  - React/CxxBridge (0.59.10):
+    - Folly (= 2018.10.22.00)
+    - React/Core
+    - React/cxxreact
+    - React/jsiexecutor
+  - React/cxxreact (0.59.10):
+    - boost-for-react-native (= 1.63.0)
+    - DoubleConversion
+    - Folly (= 2018.10.22.00)
+    - glog
+    - React/jsinspector
+  - React/DevSupport (0.59.10):
+    - React/Core
+    - React/RCTWebSocket
+  - React/fishhook (0.59.10)
+  - React/jsi (0.59.10):
+    - DoubleConversion
+    - Folly (= 2018.10.22.00)
+    - glog
+  - React/jsiexecutor (0.59.10):
+    - DoubleConversion
+    - Folly (= 2018.10.22.00)
+    - glog
+    - React/cxxreact
+    - React/jsi
+  - React/jsinspector (0.59.10)
+  - React/RCTAnimation (0.59.10):
+    - React/Core
+  - React/RCTBlob (0.59.10):
+    - React/Core
+  - React/RCTNetwork (0.59.10):
+    - React/Core
+  - React/RCTText (0.59.10):
+    - React/Core
+  - React/RCTWebSocket (0.59.10):
+    - React/Core
+    - React/fishhook
+    - React/RCTBlob
+  - yoga (0.59.10.React)
+
+DEPENDENCIES:
+  - DoubleConversion (from `../node_modules/react-native/third-party-podspecs/DoubleConversion.podspec`)
+  - Folly (from `../node_modules/react-native/third-party-podspecs/Folly.podspec`)
+  - glog (from `../node_modules/react-native/third-party-podspecs/glog.podspec`)
+  - React/Core (from `../node_modules/react-native`)
+  - React/CxxBridge (from `../node_modules/react-native`)
+  - React/DevSupport (from `../node_modules/react-native`)
+  - React/RCTAnimation (from `../node_modules/react-native`)
+  - React/RCTNetwork (from `../node_modules/react-native`)
+  - React/RCTText (from `../node_modules/react-native`)
+  - React/RCTWebSocket (from `../node_modules/react-native`)
+  - yoga (from `../node_modules/react-native/ReactCommon/yoga`)
+
+SPEC REPOS:
+  trunk:
+    - boost-for-react-native
+
+EXTERNAL SOURCES:
+  DoubleConversion:
+    :podspec: "../node_modules/react-native/third-party-podspecs/DoubleConversion.podspec"
+  Folly:
+    :podspec: "../node_modules/react-native/third-party-podspecs/Folly.podspec"
+  glog:
+    :podspec: "../node_modules/react-native/third-party-podspecs/glog.podspec"
+  React:
+    :path: "../node_modules/react-native"
+  yoga:
+    :path: "../node_modules/react-native/ReactCommon/yoga"
+
+SPEC CHECKSUMS:
+  boost-for-react-native: 39c7adb57c4e60d6c5479dd8623128eb5b3f0f2c
+  DoubleConversion: bb338842f62ab1d708ceb63ec3d999f0f3d98ecd
+  Folly: de497beb10f102453a1afa9edbf8cf8a251890de
+  glog: aefd1eb5dda2ab95ba0938556f34b98e2da3a60d
+  React: 36d0768f9e93be2473b37e7fa64f92c1d5341eef
+  yoga: 684513b14b03201579ba3cee20218c9d1298b0cc
+
+PODFILE CHECKSUM: 854427a40221b5f8b4a3e91292534e551304eba0
+
+COCOAPODS: 1.9.1