Add test case for testDocCPluginForBinaryDependency

Fixtures/Miscellaneous/Plugins/DocCForBinaryDependency/Package.swift

@@ -0,0 +1,25 @@
+// swift-tools-version: 6.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "DemoKit",
+    products: [
+        .library(name: "DemoKit", targets: ["DemoKit"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/swiftlang/swift-docc-plugin", from: "1.0.0"),
+    ],
+    targets: [
+        .binaryTarget(
+            name: "MMKV",
+            url: "https://github.com/Kyle-Ye/MMKV/releases/download/v1.3.5-binary/MMKV.xcframework.zip",
+            checksum: "181709ac82514e7f243b338e2ac221c203741837e7f51e1922582d3f132d5b78"
+        ),
+        .target(
+            name: "DemoKit",
+            dependencies: ["MMKV"]
+        ),   
+    ]
+)

Fixtures/Miscellaneous/Plugins/DocCForBinaryDependency/Sources/DemoKit/DemoKit.swift

@@ -0,0 +1,8 @@
+import MMKV
+
+public struct Demo {
+    public static func greeting() {
+        let _ = MMKV()
+        print("Hello")
+    }
+}

Tests/BuildTests/PluginsBuildPlanTests.swift

@@ -79,4 +79,14 @@ final class PluginsBuildPlanTests: XCTestCase {
             )
         }
     }
+
+    #if canImport(Darwin) // xcframework support is only supported on Darwin platform
+    func testDocCPluginForBinaryDependency() async throws {
+        try await fixture(name: "Miscellaneous/Plugins/DocCForBinaryDependency") { fixturePath in
+            // Before we add -F support, this call will throw since the command will abort with a non-zero exit code
+            let (stdout, _) = try await executeSwiftPackage(fixturePath, extraArgs: ["generate-documentation", "--target", "DemoKit"])
+            XCTAssertTrue(localFileSystem.exists(fixturePath.appending(RelativePath(".build/plugins/Swift-DocC/outputs/DemoKit.doccarchive/documentation/demokit/demo/greeting()/index.html"))))
+        }
+    }
+    #endif
 }