Add pre and post-gen commands (#759)

* add pre and post-gen commands

* update changelog

* run gen scripts in project directory

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Next Version
 
 #### Added
+- Added pre and post command options. Useful for running `pod install` in combination with `--use-cache` [#759](https://github.com/yonaskolb/XcodeGen/pull/759) @yonaskolb
 - Support for language and region settings on a target basis [#728](https://github.com/yonaskolb/XcodeGen/pull/728) @FranzBusch
 - Added option to generate only Info.plist files with `--only-plists` [#739](https://github.com/yonaskolb/XcodeGen/pull/739) @namolnad
 - Added the option to specify a `simulateLocation` in a scheme [#722](https://github.com/yonaskolb/XcodeGen/issues/722) @basvankuijck

Docs/FAQ.md

@@ -12,9 +12,12 @@ Absolutely. You will get the most out of XcodeGen by adding your project to your
 If files were added or removed in the new checkout you will most likely need to run `xcodegen` again so that your project will reference all your files. Unfortunately this is a manual step at the moment, but in the future this could be automated.
 
 For now you can always add xcodegen as a git `post-checkout` hook.
+It's recommended to use `--use-cache` so that the project is not needlessly generated.
  
 ## Can I use CocoaPods
-Yes, simply generate your project and then run `pod install` which will integrate with your project and create a workspace.
+Yes, you will just need to run `pod install` after the project is generated to integrate Cocoapods changes.
+
+It's recommended to use a combination of `--use-cache` and the `postGenCommand` option which will only generate the project if required, and then only run `pod install` if the project has been regenerated.
 
 ## Can I use Crashlytics
 Yes, but you need to use a little trick when using CocoaPods. Add this script in your `Podfile`:

Docs/ProjectSpec.md

@@ -123,12 +123,15 @@ Note that target names can also be changed by adding a `name` property to a targ
 - [ ] **generateEmptyDirectories**: **Bool** - If this is `true` then empty directories will be added to project too else will be missed. Defaults to `false`.
 - [ ] **findCarthageFrameworks**: **Bool** - When this is set to `true`, all the invididual frameworks for Carthage dependencies will automatically be found. This property can be overriden individually for each carthage dependency - for more details see See **findFrameworks** in the [Dependency](#dependency) section. Defaults to `false`.
 - [ ] **localPackagesGroup**: **String** - The group name that local packages are put into. This defaults to `Packages`
+- [ ] **preGenCommand**: **String** - A bash command to run before the project has been generated. If the project isn't generated due to no changes when using the cache then this won't run. This is useful for running things like generating resources files before the project is regenerated.
+- [ ] **postGenCommand**: **String** - A bash command to run after the project has been generated. If the project isn't generated due to no changes when using the cache then this won't run. This is useful for running things like `pod install` only if the project is actually regenerated.
 
 ```yaml
 options:
   deploymentTarget:
     watchOS: "2.0"
     tvOS: "10.0"
+  postGenCommand: pod install
 ```
 
 ### Configs

Sources/ProjectSpec/SpecOptions.swift

@@ -28,6 +28,8 @@ public struct SpecOptions: Equatable {
     public var generateEmptyDirectories: Bool
     public var findCarthageFrameworks: Bool
     public var localPackagesGroup: String?
+    public var preGenCommand: String?
+    public var postGenCommand: String?
 
     public enum ValidationType: String {
         case missingConfigs
@@ -84,7 +86,9 @@ public struct SpecOptions: Equatable {
         groupSortPosition: GroupSortPosition = groupSortPositionDefault,
         generateEmptyDirectories: Bool = generateEmptyDirectoriesDefault,
         findCarthageFrameworks: Bool = findCarthageFrameworksDefault,
-        localPackagesGroup: String? = nil
+        localPackagesGroup: String? = nil,
+        preGenCommand: String? = nil,
+        postGenCommand: String? = nil
     ) {
         self.minimumXcodeGenVersion = minimumXcodeGenVersion
         self.carthageBuildPath = carthageBuildPath
@@ -105,6 +109,8 @@ public struct SpecOptions: Equatable {
         self.generateEmptyDirectories = generateEmptyDirectories
         self.findCarthageFrameworks = findCarthageFrameworks
         self.localPackagesGroup = localPackagesGroup
+        self.preGenCommand = preGenCommand
+        self.postGenCommand = postGenCommand
     }
 }
 
@@ -133,6 +139,8 @@ extension SpecOptions: JSONObjectConvertible {
         generateEmptyDirectories = jsonDictionary.json(atKeyPath: "generateEmptyDirectories") ?? SpecOptions.generateEmptyDirectoriesDefault
         findCarthageFrameworks = jsonDictionary.json(atKeyPath: "findCarthageFrameworks") ?? SpecOptions.findCarthageFrameworksDefault
         localPackagesGroup = jsonDictionary.json(atKeyPath: "localPackagesGroup")
+        preGenCommand = jsonDictionary.json(atKeyPath: "preGenCommand")
+        postGenCommand = jsonDictionary.json(atKeyPath: "postGenCommand")
     }
 }
 
@@ -154,6 +162,8 @@ extension SpecOptions: JSONEncodable {
             "tabWidth": tabWidth.flatMap { Int($0) },
             "defaultConfig": defaultConfig,
             "localPackagesGroup": localPackagesGroup,
+            "preGenCommand": preGenCommand,
+            "postGenCommand": postGenCommand,
         ]
 
         if settingPresets != SpecOptions.settingPresetsDefault {

Sources/XcodeGenCLI/Commands/GenerateCommand.swift

@@ -79,6 +79,11 @@ class GenerateCommand: ProjectCommand {
             throw GenerationError.validationError(error)
         }
 
+        // run pre gen command
+        if let command = project.options.preGenCommand {
+            try Task.run(bash: command, directory: projectDirectory.absolute().string)
+        }
+
         // generate plists
         info("⚙️  Generating plists...")
         let fileWriter = FileWriter(project: project)
@@ -119,6 +124,11 @@ class GenerateCommand: ProjectCommand {
                 info("Failed to write cache: \(error.localizedDescription)")
             }
         }
+
+        // run post gen command
+        if let command = project.options.postGenCommand {
+            try Task.run(bash: command, directory: projectDirectory.absolute().string)
+        }
     }
 
     func info(_ string: String) {

Tests/Fixtures/TestProject/project.yml

@@ -9,6 +9,8 @@ options:
   deploymentTarget:
     watchOS: 4.0
   groupSortPosition: top
+  preGenCommand: echo "This is a pre-gen command"
+  postGenCommand: scripts/script.sh
 fileGroups:
   - Configs
   - FileGroup

Tests/ProjectSpecTests/SpecLoadingTests.swift

@@ -1070,7 +1070,9 @@ class SpecLoadingTests: XCTestCase {
                         watchOS: "3.0",
                         macOS: "10.12.1"
                     ),
-                    findCarthageFrameworks: true
+                    findCarthageFrameworks: true,
+                    preGenCommand: "swiftgen",
+                    postGenCommand: "pod install"
                 )
                 let expected = Project(name: "test", options: options)
                 let dictionary: [String: Any] = ["options": [
@@ -1081,6 +1083,8 @@ class SpecLoadingTests: XCTestCase {
                     "developmentLanguage": "ja",
                     "deploymentTarget": ["iOS": 11.1, "tvOS": 10.0, "watchOS": "3", "macOS": "10.12.1"],
                     "findCarthageFrameworks": true,
+                    "preGenCommand": "swiftgen",
+                    "postGenCommand": "pod install",
                 ]]
                 let parsedSpec = try getProjectSpec(dictionary)
                 try expect(parsedSpec) == expected