Suggest completions within string literals in type arguments

Author: mkantor

src/services/completions.ts

@@ -5768,7 +5768,8 @@ function tryGetTypeLiteralNode(node: Node): TypeLiteralNode | undefined {
     return undefined;
 }
 
-function getConstraintOfTypeArgumentProperty(node: Node, checker: TypeChecker): Type | undefined {
+/** @internal */
+export function getConstraintOfTypeArgumentProperty(node: Node, checker: TypeChecker): Type | undefined {
     if (!node) return undefined;
 
     if (isTypeNode(node)) {

src/services/stringCompletions.ts

@@ -5,6 +5,7 @@ import {
     getCompletionEntriesFromSymbols,
     getDefaultCommitCharacters,
     getPropertiesForObjectExpression,
+    getConstraintOfTypeArgumentProperty,
     Log,
     SortText,
 } from "./_namespaces/ts.Completions.js";
@@ -509,7 +510,12 @@ function getStringLiteralCompletionEntries(sourceFile: SourceFile, node: StringL
 
     function fromUnionableLiteralType(grandParent: Node): StringLiteralCompletionsFromTypes | StringLiteralCompletionsFromProperties | undefined {
         switch (grandParent.kind) {
+            case SyntaxKind.CallExpression:
             case SyntaxKind.ExpressionWithTypeArguments:
+            case SyntaxKind.JsxOpeningElement:
+            case SyntaxKind.JsxSelfClosingElement:
+            case SyntaxKind.NewExpression:
+            case SyntaxKind.TaggedTemplateExpression:
             case SyntaxKind.TypeReference: {
                 const typeArgument = findAncestor(parent, n => n.parent === grandParent) as LiteralTypeNode;
                 if (typeArgument) {
@@ -529,6 +535,8 @@ function getStringLiteralCompletionEntries(sourceFile: SourceFile, node: StringL
                     return undefined;
                 }
                 return stringLiteralCompletionsFromProperties(typeChecker.getTypeFromTypeNode(objectType));
+            case SyntaxKind.PropertySignature:
+                return { kind: StringLiteralCompletionKind.Types, types: getStringLiteralTypes(getConstraintOfTypeArgumentProperty(grandParent, typeChecker)), isNewIdentifier: false };
             case SyntaxKind.UnionType: {
                 const result = fromUnionableLiteralType(walkUpParentheses(grandParent.parent));
                 if (!result) {

tests/cases/fourslash/completionListInTypeLiteralInTypeParameter18.ts

@@ -0,0 +1,24 @@
+/// <reference path="fourslash.ts" />
+
+////class Foo<T extends { x: 'one' | 'two' }> {}
+////function foo<T extends { x: 'one' | 'two' }>() {}
+////declare function tag<T extends { x: 'one' | 'two' }>(x: TemplateStringsArray): void;
+////declare function decorator<T extends { x: 'one' | 'two' }>(...args: unknown[]): never
+////
+////type A = Foo<{ x: '/*0*/' }>;
+////new Foo<{ x: '/*1*/' }>();
+////foo<{ x: '/*2*/' }>();
+////foo<{ x: '/*3*/' }>;
+////Foo<{ x: '/*4*/' }>;
+////tag<{ x: '/*5*/' }>``;
+////class { @decorator<{ x: '/*6*/' }>; method() {} }
+
+verify.completions(
+    { marker: "0", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "1", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "2", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "3", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "4", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "5", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "6", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+);

tests/cases/fourslash/completionListInTypeLiteralInTypeParameter19.ts

@@ -0,0 +1,24 @@
+/// <reference path="fourslash.ts" />
+
+////class Foo<T extends 'one' | 'two'> {}
+////function foo<T extends 'one' | 'two'>() {}
+////declare function tag<T extends 'one' | 'two'>(x: TemplateStringsArray): void;
+////declare function decorator<T extends 'one' | 'two'>(...args: unknown[]): never
+////
+////type A = Foo<'/*0*/'>;
+////new Foo<'/*1*/'>();
+////foo<'/*2*/'>();
+////foo<'/*3*/'>;
+////Foo<'/*4*/'>;
+////tag<'/*5*/'>``;
+////class { @decorator<'/*6*/'>; method() {} }
+
+verify.completions(
+    { marker: "0", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "1", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "2", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "3", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "4", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "5", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "6", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+);

tests/cases/fourslash/completionListInTypeLiteralInTypeParameter20.ts

@@ -0,0 +1,18 @@
+/// <reference path="fourslash.ts" />
+
+// @jsx: preserve
+// @filename: a.tsx
+////const Component1 = <T extends { x: 'one' | 'two' }>() => <></>;
+////const Component2 = <T extends 'one' | 'two'>() => <></>;
+////
+////<Component1<{ x: '/*0*/' }>></Component>;
+////<Component1<{ x: '/*1*/' }>/>;
+////<Component2<'/*2*/'>></Component>;
+////<Component2<'/*3*/'>/>;
+
+verify.completions(
+    { marker: "0", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "1", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "2", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+    { marker: "3", unsorted: ["one", "two"], isNewIdentifierLocation: false },
+);