Fix a parser bug that caused G< > to be parsed correctly but not G<>

Author: ahoppen

Sources/SwiftParser/Types.swift

@@ -346,7 +346,7 @@ extension Parser {
     } else {
       name = missingToken(.identifier)
     }
-    if self.atContextualPunctuator("<") {
+    if self.atContextualPunctuator("<") || self.currentToken.starts(with: "<") {
       return (name, self.parseGenericArguments())
     }
     return (name, nil)

Tests/SwiftParserTest/VariadicGenericsTests.swift

@@ -531,16 +531,36 @@ final class TypeParameterPackTests: XCTestCase {
 
   func testVariadicTypes() {
     assertParse(
-      """
-      let _: G< > = G()
-      let _: G<repeat each T> = G()
-      let _: G<Int, repeat each T> = G()
-      let _ = G< >.self
-      let _ = G<repeat each T>.self
-      let _ = G<Int, repeat each T>.self
-      """
+      "let _: G< > = G()",
+      substructure: Syntax(
+        SimpleTypeIdentifierSyntax(
+          name: .identifier("G"),
+          genericArgumentClause: GenericArgumentClauseSyntax(
+            leftAngleBracket: .leftAngleToken(trailingTrivia: .space),
+            arguments: GenericArgumentListSyntax([]),
+            rightAngleBracket: .rightAngleToken(trailingTrivia: .space)
+          )
+        )
+      )
     )
-
+    assertParse(
+      "let _: G<> = G()",
+      substructure: Syntax(
+        SimpleTypeIdentifierSyntax(
+          name: .identifier("G"),
+          genericArgumentClause: GenericArgumentClauseSyntax(
+            leftAngleBracket: .leftAngleToken(trailingTrivia: .space),
+            arguments: GenericArgumentListSyntax([]),
+            rightAngleBracket: .rightAngleToken(trailingTrivia: .space)
+          )
+        )
+      )
+    )
+    assertParse("let _: G<repeat each T> = G()")
+    assertParse("let _: G<Int, repeat each T> = G()")
+    assertParse("let _ = G< >.self")
+    assertParse("let _ = G<repeat each T>.self")
+    assertParse("let _ = G<Int, repeat each T>.self")
   }
 
   func testMissingCommaInType() throws {