Add test case

Author: IAmArthurAdams

tests/cases/fourslash/jsxAttributeCompletionStyleAutoSignalish.ts

@@ -0,0 +1,52 @@
+/// <reference path="fourslash.ts" />
+
+// @Filename: foo.tsx
+//// declare namespace JSX {
+////     interface Element { }
+////     interface SignalLike<T> {
+////         value: T;
+////         peek(): T;
+////         subscribe(fn: (value: T) => void): () => void;
+////     }
+////     type Signalish<T> = T | SignalLike<T>;
+////     interface IntrinsicElements {
+////         div: {
+////             class?: Signalish<string | undefined>;
+////             id?: Signalish<string | undefined>;
+////             title?: Signalish<string | undefined>;
+////             disabled?: Signalish<boolean | undefined>;
+////             'data-testid'?: Signalish<string | undefined>;
+////             role?: Signalish<string | undefined>;
+////             // For comparison - pure string type should still work
+////             pureString?: string;
+////             // Boolean-like should not get quotes
+////             booleanProp?: boolean;
+////         }
+////     }
+//// }
+////
+//// <div [|prop_/**/|] />
+
+// Test that string-like Signalish types prefer quotes over braces
+verify.completions({
+    marker: "",
+    includes: [
+        {
+            name: "class",
+            insertText: "class=\"$1\"",
+            isSnippet: true,
+            sortText: completion.SortText.OptionalMember,
+        },
+        {
+            name: "id", 
+            insertText: "id=\"$1\"",
+            isSnippet: true,
+            sortText: completion.SortText.OptionalMember,
+        },
+    ],
+    preferences: {
+        jsxAttributeCompletionStyle: "auto",
+        includeCompletionsWithSnippetText: true,
+        includeCompletionsWithInsertText: true,
+    }
+});