Invalidate test target cache on project changes (#161)

Adding or removing test files were previously not causing the test
target cache to invalidate (unlike the source target cache), which was
causing thunk stubs to not generate for newly referenced mocked types.

Sources/MockingbirdCli/Interface/Generator+PruningPipeline.swift

@@ -82,7 +82,8 @@ extension Generator {
       self.findMockedTypesOperation = findMockedTypesOperation
     }
 
-    func cache(cliVersion: String,
+    func cache(projectHash: String,
+               cliVersion: String,
                configHash: String,
                sourceRoot: Path,
                cacheDirectory: Path,
@@ -95,6 +96,7 @@ extension Generator {
         target = try TestTarget(from: pipelineTarget,
                                 sourceRoot: sourceRoot,
                                 mockedTypeNames: mockedTypeNames,
+                                projectHash: projectHash,
                                 cliVersion: cliVersion,
                                 configHash: configHash,
                                 environment: environment)
@@ -106,6 +108,7 @@ extension Generator {
         target = try TestTarget(from: pipelineTarget,
                                 sourceRoot: sourceRoot,
                                 mockedTypeNames: mockedTypeNames,
+                                projectHash: projectHash,
                                 cliVersion: cliVersion,
                                 configHash: configHash,
                                 environment: environment)
@@ -119,6 +122,7 @@ extension Generator {
   }
 
   func findCachedTestTarget(for targetName: String,
+                            projectHash: String,
                             cliVersion: String,
                             configHash: String,
                             cacheDirectory: Path,
@@ -140,6 +144,11 @@ extension Generator {
       return nil
     }
 
+    guard target.projectHash == projectHash else {
+      log("Invalidated cached test target metadata for \(targetName.singleQuoted) because the project hash changed from \(target.projectHash.singleQuoted) to \(projectHash.singleQuoted)")
+      return nil
+    }
+
     guard cliVersion == target.cliVersion else {
       log("Invalidated cached test target metadata for \(target.name.singleQuoted) because the CLI version changed from \(target.cliVersion.singleQuoted) to \(cliVersion.singleQuoted)")
       return nil

Sources/MockingbirdCli/Interface/Generator.swift

@@ -107,7 +107,9 @@ class Generator {
   func getCachedTestTarget(targetName: String) -> TargetType? {
     guard !config.disableThunkStubs,
       let cacheDirectory = testTargetCacheDirectory,
+      let projectHash = getProjectHash(config.projectPath),
       let cachedTarget = findCachedTestTarget(for: targetName,
+                                              projectHash: projectHash,
                                               cliVersion: cliVersion,
                                               configHash: configHash,
                                               cacheDirectory: cacheDirectory,
@@ -194,25 +196,26 @@ class Generator {
   }
 
   func cachePipelines(sourcePipelines: [Pipeline], pruningPipeline: PruningPipeline?) throws {
+    guard let projectHash = getProjectHash(config.projectPath) else { return }
+
     // Cache source targets for generation.
-    if let projectHash = getProjectHash(config.projectPath) {
-      try sourceTargetCacheDirectory.mkpath()
-      try sourcePipelines.forEach({
-        try $0.cache(projectHash: projectHash,
-                     cliVersion: cliVersion,
-                     configHash: configHash,
-                     sourceRoot: config.sourceRoot,
-                     cacheDirectory: sourceTargetCacheDirectory,
-                     environment: getBuildEnvironment)
-      })
-    }
+    try sourceTargetCacheDirectory.mkpath()
+    try sourcePipelines.forEach({
+      try $0.cache(projectHash: projectHash,
+                   cliVersion: cliVersion,
+                   configHash: configHash,
+                   sourceRoot: config.sourceRoot,
+                   cacheDirectory: sourceTargetCacheDirectory,
+                   environment: getBuildEnvironment)
+    })
 
     // Cache test target for thunk pruning.
     if !config.disableThunkStubs {
       if let testTargetCacheDirectory = testTargetCacheDirectory,
         let environmentSourceRoot = config.environmentSourceRoot {
         try testTargetCacheDirectory.mkpath()
-        try pruningPipeline?.cache(cliVersion: cliVersion,
+        try pruningPipeline?.cache(projectHash: projectHash,
+                                   cliVersion: cliVersion,
                                    configHash: configHash,
                                    sourceRoot: environmentSourceRoot,
                                    cacheDirectory: testTargetCacheDirectory,

Sources/MockingbirdGenerator/Parser/Project/TestTarget.swift

@@ -10,22 +10,26 @@ import PathKit
 
 public class TestTarget: CodableTarget {
   public let mockedTypeNames: [Path: Set<String>]
+  public let projectHash: String
   public let cliVersion: String
   public let configHash: String
 
   enum CodingKeys: String, CodingKey {
     case mockedTypeNames
+    case projectHash
     case cliVersion
     case configHash
   }
 
   public init<T: Target>(from target: T,
                          sourceRoot: Path,
                          mockedTypeNames: [Path: Set<String>],
+                         projectHash: String,
                          cliVersion: String,
                          configHash: String,
                          environment: () -> [String: Any]) throws {
     self.mockedTypeNames = mockedTypeNames
+    self.projectHash = projectHash
     self.cliVersion = cliVersion
     self.configHash = configHash
 
@@ -41,6 +45,7 @@ public class TestTarget: CodableTarget {
     let container = try decoder.container(keyedBy: CodingKeys.self)
 
     self.mockedTypeNames = try container.decode([Path: Set<String>].self, forKey: .mockedTypeNames)
+    self.projectHash = try container.decode(String.self, forKey: .projectHash)
     self.cliVersion = try container.decode(String.self, forKey: .cliVersion)
     self.configHash = try container.decode(String.self, forKey: .configHash)
 
@@ -51,6 +56,7 @@ public class TestTarget: CodableTarget {
     var container = encoder.container(keyedBy: CodingKeys.self)
 
     try container.encode(mockedTypeNames, forKey: .mockedTypeNames)
+    try container.encode(projectHash, forKey: .projectHash)
     try container.encode(cliVersion, forKey: .cliVersion)
     try container.encode(configHash, forKey: .configHash)