Support statically defined tags

To remove namespacing ambiguity, support statically defined tags only.

Author: plemarquand

Sources/SourceKitLSP/Swift/SwiftTestingScanner.swift

@@ -103,7 +103,10 @@ struct TestingAttributeData {
             } else if components.starts(with: ["Tag"]) {
               components = components.dropFirst(1)
             }
-            return components.joined(separator: ".")
+
+            // Tags.foo resolves to ".foo", Tags.Nested.foo resolves to "Nested.foo"
+            let prefix = components.count == 1 ? "." : ""
+            return "\(prefix)\(components.joined(separator: "."))"
           }
           return nil
       }

Tests/SourceKitLSPTests/DocumentTestDiscoveryTests.swift

@@ -585,7 +585,7 @@ final class DocumentTestDiscoveryTests: XCTestCase {
     )
   }
 
-  func testSwiftTestingTestWithStringTags() async throws {
+  func testSwiftTestingTestWithTags() async throws {
     let testClient = try await TestSourceKitLSPClient()
     let uri = DocumentURI.for(.swift)
 
@@ -622,7 +622,7 @@ final class DocumentTestDiscoveryTests: XCTestCase {
               style: TestStyle.swiftTesting,
               location: Location(uri: uri, range: positions["2️⃣"]..<positions["3️⃣"]),
               children: [],
-              tags: [TestTag(id: "red"), TestTag(id: "blue")]
+              tags: [TestTag(id: ".red"), TestTag(id: ".blue")]
             )
           ],
           tags: [TestTag(id: "green")]
@@ -702,6 +702,7 @@ final class DocumentTestDiscoveryTests: XCTestCase {
       import Testing
 
       extension Tag {
+        @Tag static var suite: Self
         @Tag static var foo: Self
         @Tag static var bar: Self
         @Tag static var baz: Self
@@ -711,7 +712,7 @@ final class DocumentTestDiscoveryTests: XCTestCase {
         }
       }
 
-      1️⃣@Suite(.tags("Suites"))
+      1️⃣@Suite(.tags(.suite))
       struct MyTests {
         2️⃣@Test(.tags(.foo, Nested.foo, Testing.Tag.bar, Tag.baz))
         func oneIsTwo() {
@@ -740,10 +741,15 @@ final class DocumentTestDiscoveryTests: XCTestCase {
               style: TestStyle.swiftTesting,
               location: Location(uri: uri, range: positions["2️⃣"]..<positions["3️⃣"]),
               children: [],
-              tags: [TestTag(id: "foo"), TestTag(id: "Nested.foo"), TestTag(id: "bar"), TestTag(id: "baz")]
+              tags: [
+                TestTag(id: ".foo"),
+                TestTag(id: "Nested.foo"),
+                TestTag(id: ".bar"),
+                TestTag(id: ".baz")
+              ]
             )
           ],
-          tags: [TestTag(id: "Suites")]
+          tags: [TestTag(id: ".suite")]
         )
       ]
     )