Add usage descriptions

Author: matt-oakes

src/commands/android_build.yml

@@ -1,14 +1,13 @@
+description: Builds the Android app at the given path with the given build types. This should be run only after installing dependencies. 
+
 parameters:
   project_path:
+    description: The path to the root of the Android project you want to build, relative to the root of the repository.
     type: string
     default: "./android"
-  app_build_type:
-    type: enum
-    enum: ["Debug", "Release"]
-    default: "Debug"
-  test_build_type:
-    type: enum
-    enum: ["debug", "release"]
+  build_type:
+    description: The build type to build. This is normally either "debug" or "release" but you may have custom build types configured for your app.
+    type: string
     default: "debug"
 
 steps:
@@ -18,18 +17,23 @@ steps:
         mkdir -p ~/.tmp/checksumfiles
         find . -type f -name 'build.gradle' -not -path "*node_modules*" -exec cat {} + >> ~/.tmp/checksumfiles/build.gradle
         find . -type f -name 'settings.gradle' -not -path "*node_modules*" -exec cat {} + >> ~/.tmp/checksumfiles/settings.gradle
+
   - restore_cache:
-      key: |
-        gradle-wrapper-{{ arch }}-{{ checksum "<<parameters.project_path>>/gradle/wrapper/gradle-wrapper.properties" }}-{{ .Environment.CACHE_VERSION }}
+      keys:
+        - gradle-wrapper-{{ arch }}-{{ checksum "<<parameters.project_path>>/gradle/wrapper/gradle-wrapper.properties" }}-{{ .Environment.CACHE_VERSION }}
+        - gradle-wrapper
+
   - restore_cache:
       keys:
         - gradle-home-cache-{{ arch }}-{{ checksum "~/.tmp/checksumfiles/build.gradle" }}-{{ checksum "~/.tmp/checksumfiles/settings.gradle" }}-{{ .Environment.CACHE_VERSION }}
         - gradle-home-cache
+
   - restore_cache:
       name: Restoring Gradle Build caches
       keys:
         - gradle-build-cache-{{ .Revision }}
         - gradle-build-cache
+
   - run:
       name: Dispersing Gradle Build caches for restoring
       command: |
@@ -38,23 +42,28 @@ steps:
           rm -rf ~/.gradle/caches/build-cache-* &&
           mkdir -p ~/.gradle/caches/ &&
           mv ~/gradle-build-caches/* ~/.gradle/caches/ || true
+
   # download and cache dependencies and Gradle
   - run:
       name: Downloading Gradle Dependencies
       command: "cd <<parameters.project_path>> && ./gradlew --max-workers 2 downloadDependencies"
+
   - save_cache:
       name: Saving Gradle wrapper cache
       paths:
         - ~/.gradle/wrapper/
       key: gradle-wrapper-{{ checksum "<<parameters.project_path>>/gradle/wrapper/gradle-wrapper.properties" }}
+
   - save_cache:
       name: Saving Gradle home cache
       paths:
         - ~/.gradle/caches/
       key: gradle-home-cache-{{ checksum "~/.tmp/checksumfiles/build.gradle" }}-{{ checksum "~/.tmp/checksumfiles/settings.gradle" }}
+
   - run:
       name: Build Android Debug APK
-      command: "cd <<parameters.project_path>> && chmod +x gradlew && ./gradlew --build-cache --max-workers 2 --continue assemble<<parameters.app_build_type>> assembleAndroidTest -DtestBuildType=<<parameters.test_build_type>> --stacktrace"
+      command: "cd <<parameters.project_path>> && chmod +x gradlew && ./gradlew --build-cache --max-workers 2 --continue assemble<<parameters.build_type>> assembleAndroidTest -DtestBuildType=<<parameters.build_type>> --stacktrace"
+
   - run:
       name: Collecting Gradle Build caches for saving
       command: |
@@ -64,6 +73,7 @@ steps:
           rm -rf ~/gradle-build-caches/* &&
           mv ~/.gradle/caches/build-cache-* ~/gradle-build-caches || true
       when: always
+
   - save_cache:
       name: Saving Gradle Build caches
       paths:

src/commands/android_emulator_start.yml

@@ -1,10 +1,22 @@
+description: Installs and starts an Android emulator with the given version and name.
+
 parameters:
+  device_name:
+    description: The name of the AVD. You use this name to tell which device to run tests on.
+    type: string
+    default: "TestingAVD"
   platform_version:
+    description: The version of android to run on the emulator. Usually in the form of "android-28".
     type: string
     default: "android-28"
   build_tools_version:
+    description: The version of the Android build tools to install.
     type: string
     default: "28.0.3"
+  logcat_grep:
+    description: ADB logs will be shown in the "Start Android Emulator" commands, but we filter it using grep to avoid noise. You can specify additional strigns to grep for. Make sure you escape special characters.
+    type: string
+    default: "com.reactnativecommunity"
 
 steps:
   - run:
@@ -29,13 +41,13 @@ steps:
 
   - run:
       name: Create Android Emulator
-      command: avdmanager create avd --force -n TestingAVD -k "system-images;<<parameters.platform_version>>;google_apis;x86" -g google_apis -d "Nexus 4"
+      command: avdmanager create avd --force -n <<parameters.device_name>> -k "system-images;<<parameters.platform_version>>;google_apis;x86" -g google_apis -d "Nexus 4"
 
   - run:
       name: Start Android Emulator in background
       command: |
-        /usr/local/share/android-sdk/emulator/emulator @TestingAVD -version
-        /usr/local/share/android-sdk/emulator/emulator @TestingAVD -skin 470x860 -cores 1 -gpu auto -accel on -memory 1024 -no-audio -no-snapshot -no-boot-anim -no-window -logcat *:W | grep -i 'ReactNative\|com.reactnativecommunity\|RNCNetInfo'
+        /usr/local/share/android-sdk/emulator/emulator @<<parameters.device_name>> -version
+        /usr/local/share/android-sdk/emulator/emulator @<<parameters.device_name>> -skin 470x860 -cores 1 -gpu auto -accel on -memory 1024 -no-audio -no-snapshot -no-boot-anim -no-window -logcat *:W | grep -i 'ReactNative\|<<parameters.logcat_grep>>'
       background: true
 
   - run:

src/commands/ios_simulator_start.yml

@@ -1,5 +1,8 @@
+description: Starts an iOS simulator with the given name.
+
 parameters:
   device:
+    description: The type of device you want to start.
     type: string
     default: "iPhone X"
 

src/commands/setup_macos_executor.yml

@@ -1,3 +1,5 @@
+description: Installs the required packages to build and test Android and iOS applications on the MacOS executor. You need to run this before running any other command on those executors.
+
 steps:
   - run:
       name: Configure Environment Variables

src/commands/yarn_install.yml

@@ -1,17 +1,21 @@
+description: Install Javascript dependencies using Yarn. This command correctly configures the cache for any number of package.json and yarn.lock files.
+
 steps:
   - run:
       name: Create cache checksum file
       command: |
         mkdir -p ~/.tmp/checksumfiles
         find . -type f -name 'package.json' -not -path "*node_modules*" -exec cat {} + >> ~/.tmp/checksumfiles/package.json
+        find . -type f -name 'yarn.lock' -not -path "*node_modules*" -exec cat {} + >> ~/.tmp/checksumfiles/yarn.lock
   - restore_cache:
-      key: |
-        yarn-cache-{{ arch }}-{{ checksum "~/.tmp/checksumfiles/package.json" }}-{{ checksum "yarn.lock" }}-{{ .Environment.CACHE_VERSION }}
+      keys:
+        - yarn-cache-{{ arch }}-{{ checksum "~/.tmp/checksumfiles/package.json" }}-{{ checksum "~/.tmp/checksumfiles/yarn.lock" }}-{{ .Environment.CACHE_VERSION }}
+        - yarn-cache
   - run:
       name: Yarn Install
       command: yarn install --non-interactive --cache-folder ~/.cache/yarn
   - save_cache:
       paths:
         - ~/.cache/yarn
       key: |
-        yarn-cache-{{ arch }}-{{ checksum "~/.tmp/checksumfiles/package.json" }}-{{ checksum "yarn.lock" }}-{{ .Environment.CACHE_VERSION }}
+        yarn-cache-{{ arch }}-{{ checksum "~/.tmp/checksumfiles/package.json" }}-{{ checksum "~/.tmp/checksumfiles/yarn.lock" }}-{{ .Environment.CACHE_VERSION }}