Add tests coverage for new tag: prefix behavior for both --filter and --skip

Author: gmedori

Tests/TestingTests/SwiftPMTests.swift

@@ -20,6 +20,10 @@ private func configurationForEntryPoint(withArguments args: [String]) throws ->
   return try configurationForEntryPoint(from: args)
 }
 
+private extension Tag {
+  @Tag static var testTag: Self
+}
+
 /// Reads event stream output from the provided file matching event stream
 /// version `V`.
 private func decodedEventStreamRecords<V: ABI.Version>(fromPath filePath: String) throws -> [ABI.Record<V>] {
@@ -116,6 +120,18 @@ struct SwiftPMTests {
     #expect(!planTests.contains(test2))
   }
 
+
+  @Test("--filter argument with tag: prefix")
+  func filterByTag() async throws {
+    let configuration = try configurationForEntryPoint(withArguments: ["PATH", "--filter", "tag:testTag"])
+    let test1 = Test(.tags(.testTag),name: "hello") {}
+    let test2 = Test(name: "goodbye") {}
+    let plan = await Runner.Plan(tests: [test1, test2], configuration: configuration)
+    let planTests = plan.steps.map(\.test)
+    #expect(planTests.contains(test1))
+    #expect(!planTests.contains(test2))
+  }
+
   @Test("Multiple --filter arguments")
   func multipleFilter() async throws {
     let configuration = try configurationForEntryPoint(withArguments: ["PATH", "--filter", "hello", "--filter", "sorry"])
@@ -159,6 +175,17 @@ struct SwiftPMTests {
     #expect(planTests.contains(test2))
   }
 
+  @Test("--skip argument with tag: prefix")
+  func skipByTag() async throws {
+    let configuration = try configurationForEntryPoint(withArguments: ["PATH", "--skip", "tag:testTag"])
+    let test1 = Test(.tags(.testTag),name: "hello") {}
+    let test2 = Test(name: "goodbye") {}
+    let plan = await Runner.Plan(tests: [test1, test2], configuration: configuration)
+    let planTests = plan.steps.map(\.test)
+    #expect(!planTests.contains(test1))
+    #expect(planTests.contains(test2))
+  }
+
   @Test("--filter or --skip argument as last argument")
   func filterOrSkipAsLast() async throws {
     _ = try configurationForEntryPoint(withArguments: ["PATH", "--filter"])