Rename and properly document ValTestRunner => AnnotatedValFileTest

Tests/ValTests/CXXTests.swift

@@ -4,16 +4,16 @@ import FrontEnd
 import Utils
 import XCTest
 
-final class CXXTests: XCTestCase, ValTestRunner {
+final class CXXTests: XCTestCase, AnnotatedValFileTest {
 
-  static var testCaseDirectoryPath: String { "TestCases/CXX" }
+  static var valSourceDirectory: String { "TestCases/CXX" }
 
   func testTranspiler() throws {
     // Prepare an AST with the core module loaded.
     var baseAST = AST()
     baseAST.importCoreModule()
 
-    try runValTests(
+    try checkAnnotatedValFiles(
       { (name, source) -> CXXAnnotationHandler in
         // Create a module for the input.
         var ast = baseAST

Tests/ValTests/EmitterTests.swift

@@ -4,16 +4,16 @@ import IR
 import Utils
 import XCTest
 
-final class EmitterTests: XCTestCase, ValTestRunner {
+final class EmitterTests: XCTestCase, AnnotatedValFileTest {
 
-  static var testCaseDirectoryPath: String { "TestCases/Lowering" }
+  static var valSourceDirectory: String { "TestCases/Lowering" }
 
   func testEmitter() throws {
     // Prepare an AST with the core module loaded.
     var baseAST = AST()
     baseAST.importCoreModule()
 
-    try runValTests(
+    try checkAnnotatedValFiles(
       { (name, source) -> DefaultTestAnnotationHandler in
         // Create a module for the input.
         var ast = baseAST

Tests/ValTests/ParserTests.swift

@@ -5,12 +5,12 @@ import XCTest
 
 @testable import FrontEnd
 
-final class ParserTests: XCTestCase, ValTestRunner {
+final class ParserTests: XCTestCase, AnnotatedValFileTest {
 
-  static var testCaseDirectoryPath: String { "TestCases/Parsing" }
+  static var valSourceDirectory: String { "TestCases/Parsing" }
 
   func testParser() throws {
-    try runValTests(
+    try checkAnnotatedValFiles(
       { (name, source) -> DefaultTestAnnotationHandler in
         // Create a module for the input.
         var ast = AST()

Tests/ValTests/TypeCheckerTests.swift

@@ -2,16 +2,16 @@ import Core
 import FrontEnd
 import XCTest
 
-final class TypeCheckerTests: XCTestCase, ValTestRunner {
+final class TypeCheckerTests: XCTestCase, AnnotatedValFileTest {
 
-  static var testCaseDirectoryPath: String { "TestCases/TypeChecking" }
+  static var valSourceDirectory: String { "TestCases/TypeChecking" }
 
   func testTypeChecker() throws {
     // Prepare an AST with the core module loaded.
     var baseAST = AST()
     baseAST.importCoreModule()
 
-    try runValTests(
+    try checkAnnotatedValFiles(
       { (name, source) -> DefaultTestAnnotationHandler in
         // Create a module for the input.
         var ast = baseAST

Tests/ValTests/Utils/ValTestRunner.swift → Tests/ValTests/Utils/AnnotatedValFileTest.swift

@@ -2,23 +2,24 @@ import Core
 import Utils
 import XCTest
 
-/// A XCTestCase that runs val test cases.
-protocol ValTestRunner: XCTestCase {
+/// A XCTestCase that preprocesses the ".val" files in a directory, and then checks the result of
+/// that preprocessing against annotations embedded in the file's comments.
+protocol AnnotatedValFileTest: XCTestCase {
 
-  /// The directory containing the Val test cases of this type.
-  static var testCaseDirectoryPath: String { get }
+  /// The directory containing the Val sources to test.
+  static var valSourceDirectory: String { get }
 
 }
 
-extension ValTestRunner {
+extension AnnotatedValFileTest {
 
-  /// Runs the test cases found in `Self.testCaseDirectoryPath` with `runSteps` and handle the
+  /// Runs the test cases found in `Self.valSourceDirectory` with `runSteps` and handle the
   /// result of each case with an instance of `handler`.
-  func runValTests<Handler: TestAnnotationHandler>(
+  func checkAnnotatedValFiles<Handler: TestAnnotationHandler>(
     _ runSteps: (_ xcTestName: String, _ source: SourceFile) throws -> Handler
   ) throws {
     let testCaseDirectory = try XCTUnwrap(
-      Bundle.module.url(forResource: Self.testCaseDirectoryPath, withExtension: nil),
+      Bundle.module.url(forResource: Self.valSourceDirectory, withExtension: nil),
       "No test cases")
 
     func _run(xcTestName: String, url: URL, activity: XCTActivity) throws -> [XCTIssue] {