Also check TypeAlias for unused type parameters

DickvdBrink · DickvdBrink · commit 09be53778690 · 2017-06-22T16:41:40.000+02:00
Fixes microsoft#15208
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -19426,6 +19426,9 @@ namespace ts {
                         case SyntaxKind.ConstructorType:
                             checkUnusedTypeParameters(<FunctionLikeDeclaration>node);
                             break;
+                        case SyntaxKind.TypeAliasDeclaration:
+                            checkUnusedTypeParameters(<TypeAliasDeclaration>node);
+                            break;
                     }
                 }
             }
@@ -19503,7 +19506,7 @@ namespace ts {
             }
         }
 
-        function checkUnusedTypeParameters(node: ClassDeclaration | ClassExpression | FunctionDeclaration | MethodDeclaration | FunctionExpression | ArrowFunction | ConstructorDeclaration | SignatureDeclaration | InterfaceDeclaration) {
+        function checkUnusedTypeParameters(node: ClassDeclaration | ClassExpression | FunctionDeclaration | MethodDeclaration | FunctionExpression | ArrowFunction | ConstructorDeclaration | SignatureDeclaration | InterfaceDeclaration | TypeAliasDeclaration) {
             if (compilerOptions.noUnusedLocals && !isInAmbientContext(node)) {
                 if (node.typeParameters) {
                     // Only report errors on the last declaration for the type parameter container;
@@ -21208,6 +21211,7 @@ namespace ts {
             checkTypeNameIsReserved(node.name, Diagnostics.Type_alias_name_cannot_be_0);
             checkTypeParameters(node.typeParameters);
             checkSourceElement(node.type);
+            registerForUnusedIdentifiersCheck(node);
         }
 
         function computeEnumMemberValues(node: EnumDeclaration) {

Original file line number	Diff line number	Diff line change
`@@ -19426,6 +19426,9 @@ namespace ts {`
`19426`	`19426`	`case SyntaxKind.ConstructorType:`
`19427`	`19427`	`checkUnusedTypeParameters(<FunctionLikeDeclaration>node);`
`19428`	`19428`	`break;`
	`19429`	`+ case SyntaxKind.TypeAliasDeclaration:`
	`19430`	`+ checkUnusedTypeParameters(<TypeAliasDeclaration>node);`
	`19431`	`+ break;`
`19429`	`19432`	`}`
`19430`	`19433`	`}`
`19431`	`19434`	`}`
`@@ -19503,7 +19506,7 @@ namespace ts {`
`19503`	`19506`	`}`
`19504`	`19507`	`}`
`19505`	`19508`
`19506`		`- function checkUnusedTypeParameters(node: ClassDeclaration \| ClassExpression \| FunctionDeclaration \| MethodDeclaration \| FunctionExpression \| ArrowFunction \| ConstructorDeclaration \| SignatureDeclaration \| InterfaceDeclaration) {`
	`19509`	`+ function checkUnusedTypeParameters(node: ClassDeclaration \| ClassExpression \| FunctionDeclaration \| MethodDeclaration \| FunctionExpression \| ArrowFunction \| ConstructorDeclaration \| SignatureDeclaration \| InterfaceDeclaration \| TypeAliasDeclaration) {`
`19507`	`19510`	`if (compilerOptions.noUnusedLocals && !isInAmbientContext(node)) {`
`19508`	`19511`	`if (node.typeParameters) {`
`19509`	`19512`	`// Only report errors on the last declaration for the type parameter container;`
`@@ -21208,6 +21211,7 @@ namespace ts {`
`21208`	`21211`	`checkTypeNameIsReserved(node.name, Diagnostics.Type_alias_name_cannot_be_0);`
`21209`	`21212`	`checkTypeParameters(node.typeParameters);`
`21210`	`21213`	`checkSourceElement(node.type);`
	`21214`	`+ registerForUnusedIdentifiersCheck(node);`
`21211`	`21215`	`}`
`21212`	`21216`
`21213`	`21217`	`function computeEnumMemberValues(node: EnumDeclaration) {`