From 1d7858e0230ff08cbf84e3a019aa81436e0970ab Mon Sep 17 00:00:00 2001
From: Richard Howell <richardh@uber.com>
Date: Fri, 4 Oct 2019 16:03:43 -0700
Subject: [PATCH] call delegate on build targets change

---
 Sources/BuildServerProtocol/BuildTargets.swift      |  2 +-
 Sources/BuildServerProtocol/Messages.swift          |  2 +-
 Sources/SKCore/BuildServerBuildSystem.swift         |  5 +++++
 Sources/SKCore/BuildSystemDelegate.swift            | 10 ++++++++--
 Sources/SourceKit/SourceKitServer.swift             |  5 +++++
 Tests/SKCoreTests/BuildServerBuildSystemTests.swift |  4 ++++
 6 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/Sources/BuildServerProtocol/BuildTargets.swift b/Sources/BuildServerProtocol/BuildTargets.swift
index 6ca21a59..03ebf045 100644
--- a/Sources/BuildServerProtocol/BuildTargets.swift
+++ b/Sources/BuildServerProtocol/BuildTargets.swift
@@ -211,7 +211,7 @@ public struct OutputsItem: Codable, Hashable {
 /// The build target changed notification is sent from the server to the client
 /// to signal a change in a build target. The server communicates during the
 /// initialize handshake whether this method is supported or not.
-public struct BuildTargetChangedNotification: NotificationType {
+public struct BuildTargetsChangedNotification: NotificationType {
   public static let method: String = "buildTarget/didChange"
 
   public var changes: [BuildTargetEvent]
diff --git a/Sources/BuildServerProtocol/Messages.swift b/Sources/BuildServerProtocol/Messages.swift
index d8259644..9feee786 100644
--- a/Sources/BuildServerProtocol/Messages.swift
+++ b/Sources/BuildServerProtocol/Messages.swift
@@ -22,7 +22,7 @@ fileprivate let requestTypes: [_RequestType.Type] = [
 ]
 
 fileprivate let notificationTypes: [NotificationType.Type] = [
-  BuildTargetChangedNotification.self,
+  BuildTargetsChangedNotification.self,
   ExitBuildNotification.self,
   FileOptionsChangedNotification.self,
   InitializedBuildNotification.self,
diff --git a/Sources/SKCore/BuildServerBuildSystem.swift b/Sources/SKCore/BuildServerBuildSystem.swift
index 11695dca..7d9cc90f 100644
--- a/Sources/SKCore/BuildServerBuildSystem.swift
+++ b/Sources/SKCore/BuildServerBuildSystem.swift
@@ -126,9 +126,14 @@ final class BuildServerHandler: LanguageServerEndpoint {
   public weak var delegate: BuildSystemDelegate? = nil
 
   override func _registerBuiltinHandlers() {
+    _register(BuildServerHandler.handleBuildTargetsChanged)
     _register(BuildServerHandler.handleFileOptionsChanged)
   }
 
+  func handleBuildTargetsChanged(_ notification: Notification<BuildTargetsChangedNotification>) {
+    self.delegate?.buildTargetsChanged(notification.params.changes)
+  }
+
   func handleFileOptionsChanged(_ notification: Notification<FileOptionsChangedNotification>) {
     // TODO: add delegate method to include the changed settings directly
     self.delegate?.fileBuildSettingsChanged([notification.params.uri])
diff --git a/Sources/SKCore/BuildSystemDelegate.swift b/Sources/SKCore/BuildSystemDelegate.swift
index 0407fbce..1eb2192f 100644
--- a/Sources/SKCore/BuildSystemDelegate.swift
+++ b/Sources/SKCore/BuildSystemDelegate.swift
@@ -9,15 +9,21 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
-
+import BuildServerProtocol
 import LanguageServerProtocol
 import TSCBasic
 
 /// Handles  build system events, such as file build settings changes.
 public protocol BuildSystemDelegate: AnyObject {
+  /// Notify the delegate that the build targets have changed.
+  ///
+  /// The callee should request new sources and outputs for the build targets of
+  /// interest.
+  func buildTargetsChanged(_ changes: [BuildTargetEvent])
 
   /// Notify the delegate that the given files' build settings have changed.
   ///
-  /// The callee should request new build settings for any of the given files that they are interested in.
+  /// The callee should request new build settings for any of the given files
+  /// that they are interested in.
   func fileBuildSettingsChanged(_ changedFiles: Set<URL>)
 }
diff --git a/Sources/SourceKit/SourceKitServer.swift b/Sources/SourceKit/SourceKitServer.swift
index 0da0f93b..864def61 100644
--- a/Sources/SourceKit/SourceKitServer.swift
+++ b/Sources/SourceKit/SourceKitServer.swift
@@ -10,6 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+import BuildServerProtocol
 import LanguageServerProtocol
 import SKCore
 import SKSupport
@@ -238,6 +239,10 @@ public final class SourceKitServer: LanguageServer {
 // MARK: - Build System Delegate
 
 extension SourceKitServer: BuildSystemDelegate {
+  public func buildTargetsChanged(_ changes: [BuildTargetEvent]) {
+    // TODO: do something with these changes once build target support is in place
+  }
+
   public func fileBuildSettingsChanged(_ changedFiles: Set<URL>) {
     guard let workspace = self.workspace else {
       return
diff --git a/Tests/SKCoreTests/BuildServerBuildSystemTests.swift b/Tests/SKCoreTests/BuildServerBuildSystemTests.swift
index 8b636ad7..64ad23ea 100644
--- a/Tests/SKCoreTests/BuildServerBuildSystemTests.swift
+++ b/Tests/SKCoreTests/BuildServerBuildSystemTests.swift
@@ -165,6 +165,10 @@ final class TestDelegate: BuildSystemDelegate {
     self.expectations = expectations
   }
 
+  func buildTargetsChanged(_ changes: [BuildTargetEvent]) {
+    
+  }
+
   func fileBuildSettingsChanged(_ changedFiles: Set<URL>) {
     for url in changedFiles {
       expectations[url]?.fulfill()