fix(40257): fix type parameters range (#40265)

src/compiler/checker.ts

@@ -33329,15 +33329,16 @@ namespace ts {
                 const { parent } = typeParameter;
                 if (parent.kind !== SyntaxKind.InferType && parent.typeParameters!.every(isTypeParameterUnused)) {
                     if (tryAddToSet(seenParentsWithEveryUnused, parent)) {
+                        const sourceFile = getSourceFileOfNode(parent);
                         const range = isJSDocTemplateTag(parent)
                             // Whole @template tag
                             ? rangeOfNode(parent)
                             // Include the `<>` in the error message
-                            : rangeOfTypeParameters(parent.typeParameters!);
+                            : rangeOfTypeParameters(sourceFile, parent.typeParameters!);
                         const only = parent.typeParameters!.length === 1;
                         const message = only ? Diagnostics._0_is_declared_but_its_value_is_never_read : Diagnostics.All_type_parameters_are_unused;
                         const arg0 = only ? name : undefined;
-                        addDiagnostic(typeParameter, UnusedKind.Parameter, createFileDiagnostic(getSourceFileOfNode(parent), range.pos, range.end - range.pos, message, arg0));
+                        addDiagnostic(typeParameter, UnusedKind.Parameter, createFileDiagnostic(sourceFile, range.pos, range.end - range.pos, message, arg0));
                     }
                 }
                 else {

src/compiler/utilities.ts

@@ -6709,9 +6709,11 @@ namespace ts {
         return { pos: getTokenPosOfNode(node), end: node.end };
     }
 
-    export function rangeOfTypeParameters(typeParameters: NodeArray<TypeParameterDeclaration>): TextRange {
+    export function rangeOfTypeParameters(sourceFile: SourceFile, typeParameters: NodeArray<TypeParameterDeclaration>): TextRange {
         // Include the `<>`
-        return { pos: typeParameters.pos - 1, end: typeParameters.end + 1 };
+        const pos = typeParameters.pos - 1;
+        const end = skipTrivia(sourceFile.text, typeParameters.end) + 1;
+        return { pos, end };
     }
 
     export interface HostWithIsSourceOfProjectReferenceRedirect {

src/services/textChanges.ts

@@ -843,7 +843,7 @@ namespace ts.textChanges {
             for (const { sourceFile, node } of this.deletedNodes) {
                 if (!this.deletedNodes.some(d => d.sourceFile === sourceFile && rangeContainsRangeExclusive(d.node, node))) {
                     if (isArray(node)) {
-                        this.deleteRange(sourceFile, rangeOfTypeParameters(node));
+                        this.deleteRange(sourceFile, rangeOfTypeParameters(sourceFile, node));
                     }
                     else {
                         deleteDeclaration.deleteDeclaration(this, deletedNodesInLists, sourceFile, node);

tests/cases/fourslash/unusedTypeParametersWithTrivia1.ts

@@ -0,0 +1,12 @@
+/// <reference path="fourslash.ts" />
+
+// @noUnusedParameters: true
+////export type Foo<
+////    T1 extends any,
+////    T2 extends any
+////> = () => void;
+
+verify.codeFix({
+    description: ts.Diagnostics.Remove_type_parameters.message,
+    newFileContent: "export type Foo = () => void;"
+});

tests/cases/fourslash/unusedTypeParametersWithTrivia2.ts

@@ -0,0 +1,9 @@
+/// <reference path="fourslash.ts" />
+
+// @noUnusedParameters: true
+////export type Foo<     T1 extends any, T2 extends any    > = () => void;
+
+verify.codeFix({
+    description: ts.Diagnostics.Remove_type_parameters.message,
+    newFileContent: "export type Foo = () => void;"
+});

tests/cases/fourslash/unusedTypeParametersWithTrivia3.ts

@@ -0,0 +1,9 @@
+/// <reference path="fourslash.ts" />
+
+// @noUnusedParameters: true
+////export type Foo</* comment */T1 extends any, T2 extends any/* comment */> = () => void;
+
+verify.codeFix({
+    description: ts.Diagnostics.Remove_type_parameters.message,
+    newFileContent: "export type Foo = () => void;"
+});

tests/cases/fourslash/unusedTypeParametersWithTrivia4.ts

@@ -0,0 +1,12 @@
+/// <reference path="fourslash.ts" />
+
+// @noUnusedParameters: true
+////export type Foo<
+////    T1 extends any,
+////    T2 extends any
+////   /* comment */> = () => void;
+
+verify.codeFix({
+    description: ts.Diagnostics.Remove_type_parameters.message,
+    newFileContent: "export type Foo = () => void;"
+});