Prepend module name to TestItem IDs

Sources/SKCore/BuildSystemManager.swift

@@ -14,6 +14,7 @@ import BuildServerProtocol
 import Dispatch
 import LSPLogging
 import LanguageServerProtocol
+import SwiftExtensions
 
 import struct TSCBasic.AbsolutePath
 
@@ -154,6 +155,37 @@ extension BuildSystemManager {
       .first
   }
 
+  /// Returns the target's module name as parsed from the `ConfiguredTarget`'s compiler arguments.
+  public func moduleName(for document: DocumentURI, in target: ConfiguredTarget) async -> String? {
+    guard let language = await self.defaultLanguage(for: document),
+      let buildSettings = await buildSettings(for: document, in: target, language: language)
+    else {
+      return nil
+    }
+
+    switch language {
+    case .swift:
+      // Module name is specified in the form -module-name MyLibrary
+      guard let moduleNameFlagIndex = buildSettings.compilerArguments.firstIndex(of: "-module-name") else {
+        return nil
+      }
+      return buildSettings.compilerArguments[safe: moduleNameFlagIndex + 1]
+    case .objective_c:
+      // Specified in the form -fmodule-name=MyLibrary
+      guard
+        let moduleNameArgument = buildSettings.compilerArguments.first(where: {
+          $0.starts(with: "-fmodule-name=")
+        }),
+        let moduleName = moduleNameArgument.split(separator: "=").last
+      else {
+        return nil
+      }
+      return String(moduleName)
+    default:
+      return nil
+    }
+  }
+
   /// Returns the build settings for `document` from `buildSystem`.
   ///
   /// Implementation detail of `buildSettings(for:language:)`.

Sources/SourceKitLSP/TestDiscovery.swift

@@ -260,7 +260,7 @@ extension SourceKitLSPServer {
 
   func workspaceTests(_ req: WorkspaceTestsRequest) async throws -> [TestItem] {
     return await self.workspaces
-      .concurrentMap { await self.tests(in: $0) }
+      .concurrentMap { await self.tests(in: $0).prefixTestsWithModuleName(workspace: $0) }
       .flatMap { $0 }
       .sorted { $0.testItem.location < $1.testItem.location }
       .mergingTestsInExtensions()
@@ -272,6 +272,7 @@ extension SourceKitLSPServer {
     languageService: LanguageService
   ) async throws -> [TestItem] {
     return try await documentTestsWithoutMergingExtensions(req, workspace: workspace, languageService: languageService)
+      .prefixTestsWithModuleName(workspace: workspace)
       .mergingTestsInExtensions()
   }
 
@@ -476,6 +477,30 @@ fileprivate extension Array<AnnotatedTestItem> {
     }
     return result
   }
+
+  func prefixTestsWithModuleName(workspace: Workspace) async -> Self {
+    return await self.asyncMap({
+      return AnnotatedTestItem(
+        testItem: await $0.testItem.prefixIDWithModuleName(workspace: workspace),
+        isExtension: $0.isExtension
+      )
+    })
+  }
+}
+
+extension TestItem {
+  fileprivate func prefixIDWithModuleName(workspace: Workspace) async -> TestItem {
+    guard let configuredTarget = await workspace.buildSystemManager.canonicalConfiguredTarget(for: self.location.uri),
+      let moduleName = await workspace.buildSystemManager.moduleName(for: self.location.uri, in: configuredTarget)
+    else {
+      return self
+    }
+
+    var newTest = self
+    newTest.id = "\(moduleName).\(newTest.id)"
+    newTest.children = await newTest.children.asyncMap({ await $0.prefixIDWithModuleName(workspace: workspace) })
+    return newTest
+  }
 }
 
 extension SwiftLanguageService {

Sources/SwiftExtensions/Array+Safe.swift

@@ -0,0 +1,19 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+extension Array {
+  /// Returns the element at the specified index if it is within the Array's
+  /// bounds, otherwise `nil`.
+  public subscript(safe index: Index) -> Element? {
+    return index >= 0 && index < count ? self[index] : nil
+  }
+}

Sources/SwiftExtensions/CMakeLists.txt

@@ -1,5 +1,6 @@
 
 add_library(SwiftExtensions STATIC
+  Array+Safe.swift
   AsyncQueue.swift
   AsyncUtils.swift
   Collection+Only.swift