Conditionally build plugins

Author: glbrntt

Package.swift

@@ -17,6 +17,42 @@
 
 import PackageDescription
 
+extension Context {
+  fileprivate static var buildPlugins: Bool {
+    let noPlugins = Context.environment.keys.contains("GRPC_SWIFT_PROTOBUF_NO_PLUGINS")
+    return !noPlugins
+  }
+}
+
+extension [Product] {
+  func removingPluginsIfNecessary() -> Self {
+    if Context.buildPlugins {
+      return self
+    } else {
+      // Remove plugin products.
+      return self.filter { !($0 is Product.Plugin) }
+    }
+  }
+}
+
+extension [Target] {
+  func removingPluginsIfNecessary() -> Self {
+    if Context.buildPlugins {
+      return self
+    } else {
+      // Remove plugin targets.
+      return self.filter { target in
+        switch target.type {
+        case .plugin:
+          return false
+        default:
+          return true
+        }
+      }
+    }
+  }
+}
+
 let products: [Product] = [
   .library(
     name: "GRPCProtobuf",
@@ -173,7 +209,7 @@ let package = Package(
     .watchOS(.v11),
     .visionOS(.v2),
   ],
-  products: products,
+  products: products.removingPluginsIfNecessary(),
   dependencies: dependencies,
-  targets: targets
+  targets: targets.removingPluginsIfNecessary()
 )