Fix grammar checking for in and out modifiers in @template tags (#4100)

Author: ahejlsberg

internal/checker/grammarchecks.go

@@ -301,11 +301,7 @@ func (c *Checker) checkGrammarModifiers(node *ast.Node /*Union[HasModifiers, Has
 				if node.Kind != ast.KindEnumDeclaration && node.Kind != ast.KindTypeParameter {
 					return c.grammarErrorOnNode(node, diagnostics.A_class_member_cannot_have_the_0_keyword, scanner.TokenToString(ast.KindConstKeyword))
 				}
-
-				// !!!
-				// parent := (isJSDocTemplateTag(node.Parent) && getEffectiveJSDocHost(node.Parent)) || node.Parent
 				parent := node.Parent
-
 				if node.Kind == ast.KindTypeParameter {
 					if !(ast.IsFunctionLikeDeclaration(parent) || ast.IsClassLike(parent) ||
 						ast.IsFunctionTypeNode(parent) || ast.IsConstructorTypeNode(parent) ||
@@ -532,10 +528,8 @@ func (c *Checker) checkGrammarModifiers(node *ast.Node /*Union[HasModifiers, Has
 				} else {
 					inOutText = "out"
 				}
-				// !!!
-				// parent := isJSDocTemplateTag(node.Parent) && (getEffectiveJSDocHost(node.Parent) || core.Find(getJSDocRoot(node.Parent). /* ? */ tags, isJSDocTypedefTag)) || node.Parent
 				parent := node.Parent
-				if node.Kind != ast.KindTypeParameter || parent != nil && !(ast.IsInterfaceDeclaration(parent) || ast.IsClassLike(parent) || ast.IsTypeAliasDeclaration(parent) || isJSDocTypedefTag(parent)) {
+				if node.Kind != ast.KindTypeParameter || parent != nil && !(ast.IsInterfaceDeclaration(parent) || ast.IsClassLike(parent) || ast.IsTypeOrJSTypeAliasDeclaration(parent)) {
 					return c.grammarErrorOnNode(modifier, diagnostics.X_0_modifier_can_only_appear_on_a_type_parameter_of_a_class_interface_or_type_alias, inOutText)
 				}
 				if flags&inOutFlag != 0 {
@@ -573,11 +567,6 @@ func (c *Checker) checkGrammarModifiers(node *ast.Node /*Union[HasModifiers, Has
 	return false
 }
 
-func isJSDocTypedefTag(_ *ast.Node) bool {
-	// !!!
-	return false
-}
-
 func (c *Checker) reportObviousModifierErrors(node *ast.Node) bool {
 	modifier := c.findFirstIllegalModifier(node)
 	if modifier == nil {

testdata/baselines/reference/submodule/conformance/jsdocTemplateTag8.errors.txt

@@ -1,10 +1,7 @@
-a.js(2,14): error TS1274: 'out' modifier can only appear on a type parameter of a class, interface or type alias
 a.js(18,1): error TS2322: Type 'Covariant<unknown>' is not assignable to type 'Covariant<string>'.
   Type 'unknown' is not assignable to type 'string'.
-a.js(21,14): error TS1274: 'in' modifier can only appear on a type parameter of a class, interface or type alias
 a.js(36,1): error TS2322: Type 'Contravariant<string>' is not assignable to type 'Contravariant<unknown>'.
   Type 'unknown' is not assignable to type 'string'.
-a.js(40,14): error TS1274: 'in' modifier can only appear on a type parameter of a class, interface or type alias
 a.js(55,1): error TS2322: Type 'Invariant<string>' is not assignable to type 'Invariant<unknown>'.
   Types of property 'f' are incompatible.
     Type '(x: string) => string' is not assignable to type '(x: unknown) => unknown'.
@@ -16,11 +13,9 @@ a.js(56,1): error TS2322: Type 'Invariant<unknown>' is not assignable to type 'I
 a.js(59,14): error TS1274: 'in' modifier can only appear on a type parameter of a class, interface or type alias
 
 
-==== a.js (8 errors) ====
+==== a.js (5 errors) ====
     /**
      * @template out T
-                 ~~~
-!!! error TS1274: 'out' modifier can only appear on a type parameter of a class, interface or type alias
      * @typedef {Object} Covariant
      * @property {T} x
      */
@@ -43,8 +38,6 @@ a.js(59,14): error TS1274: 'in' modifier can only appear on a type parameter of
 
     /**
      * @template in T
-                 ~~
-!!! error TS1274: 'in' modifier can only appear on a type parameter of a class, interface or type alias
      * @typedef {Object} Contravariant
      * @property {(x: T) => void} f
      */
@@ -67,8 +60,6 @@ a.js(59,14): error TS1274: 'in' modifier can only appear on a type parameter of
 
     /**
      * @template in out T
-                 ~~
-!!! error TS1274: 'in' modifier can only appear on a type parameter of a class, interface or type alias
      * @typedef {Object} Invariant
      * @property {(x: T) => T} f
      */