Introduce ParserTestCase

This will allow overriding the default set of
experimental features. This diff is best viewed
with whitespace disabled.

Author: hamishknight

Tests/SwiftParserTest/AbsolutePositionTests.swift

@@ -15,7 +15,7 @@ import SwiftSyntax
 import SwiftParser
 import _SwiftSyntaxTestSupport
 
-public class AbsolutePositionTests: XCTestCase {
+public class AbsolutePositionTests: ParserTestCase {
   public func testTokenAt() {
     let source =
       """

Tests/SwiftParserTest/Assertions.swift

@@ -14,7 +14,7 @@
 @_spi(RawSyntax) import SwiftParser
 import XCTest
 
-final class AttributeTests: XCTestCase {
+final class AttributeTests: ParserTestCase {
   func testMissingArgumentToAttribute() {
     assertParse(
       """

Tests/SwiftParserTest/AttributeTests.swift

@@ -14,7 +14,7 @@
 @_spi(RawSyntax) import SwiftParser
 import XCTest
 
-final class AvailabilityTests: XCTestCase {
+final class AvailabilityTests: ParserTestCase {
   func testAvailableMember() {
     assertParse(
       """

Tests/SwiftParserTest/AvailabilityTests.swift

@@ -16,7 +16,7 @@ import SwiftSyntaxBuilder
 import SwiftBasicFormat
 import XCTest
 
-final class DeclarationTests: XCTestCase {
+final class DeclarationTests: ParserTestCase {
   func testImports() {
     assertParse("import Foundation")
 

Tests/SwiftParserTest/DeclarationTests.swift

@@ -14,7 +14,7 @@
 @_spi(RawSyntax) import SwiftParser
 import XCTest
 
-final class DirectiveTests: XCTestCase {
+final class DirectiveTests: ParserTestCase {
   func testSwitchIfConfig() {
     assertParse(
       """

Tests/SwiftParserTest/DirectiveTests.swift

@@ -14,7 +14,7 @@
 @_spi(RawSyntax) import SwiftParser
 import XCTest
 
-final class ExpressionTests: XCTestCase {
+final class ExpressionTests: ParserTestCase {
   func testTernary() {
     assertParse(
       "let a =1️⃣",
@@ -1474,7 +1474,7 @@ final class ExpressionTests: XCTestCase {
   }
 }
 
-final class MemberExprTests: XCTestCase {
+final class MemberExprTests: ParserTestCase {
   func testMissing() {
     let cases: [UInt: String] = [
       #line: "",
@@ -1494,7 +1494,7 @@ final class MemberExprTests: XCTestCase {
   }
 }
 
-final class StatementExpressionTests: XCTestCase {
+final class StatementExpressionTests: ParserTestCase {
   private func ifZeroElseOne() -> ExprSyntax {
     .init(
       IfExprSyntax(

Tests/SwiftParserTest/ExpressionTests.swift

@@ -13,7 +13,7 @@
 import SwiftSyntax
 import XCTest
 
-final class ExpressionTypeTests: XCTestCase {
+final class ExpressionTypeTests: ParserTestCase {
   func testTypeExpression() {
     assertParse("_ = (any Sequence<Int>).self")
   }

Tests/SwiftParserTest/ExpressionTypeTests.swift

@@ -15,7 +15,7 @@ import SwiftSyntax
 import SwiftParser
 import _SwiftSyntaxTestSupport
 
-public class IncrementalParsingTests: XCTestCase {
+public class IncrementalParsingTests: ParserTestCase {
 
   public func testBrokenMemberFunction() {
     assertIncrementalParse(

Tests/SwiftParserTest/IncrementalParsingTests.swift

@@ -60,7 +60,7 @@ fileprivate func assertRawBytesLexeme(
   XCTAssertEqual(lexeme.diagnostic, error, file: file, line: line)
 }
 
-public class LexerTests: XCTestCase {
+public class LexerTests: ParserTestCase {
   func testIdentifiers() {
     assertLexemes(
       "Hello World",