TS Plugin: basic diagnostics and functionality for .gts files

.vscode/launch.json

@@ -75,6 +75,8 @@
         "lifeart.vscode-glimmer-syntax",
         "--disable-extension",
         "unifiedjs.vscode-mdx",
+        "--disable-extension",
+        "Vue.volar",
         "${workspaceFolder}/test-packages/ts-plugin-test-app"
       ]
     },

CONTRIBUTING.md

@@ -65,13 +65,13 @@ Glint transforms template code into TypeScript code so that it can be type-check
 ```ts
 static {
 ({} as typeof import("@glint/environment-ember-loose/-private/dsl")
-       .templateForBackingValue(this, function(𝚪, χ: typeof import("@glint/environment-ember-loose/-private/dsl")) {
+       .templateForBackingValue(this, function(__glintRef__, __glintDSL__: typeof import("@glint/environment-ember-loose/-private/dsl")) {
   {
-    const 𝛄 = χ.emitComponent(χ.resolve(χ.Globals["FooComponent"])
-      ({ desc: "notchHeight _ footer", ...χ.NamedArgsMarker }));
-    𝛄;
+    const __glintY__ = __glintDSL__.emitComponent(__glintDSL__.resolve(__glintDSL__.Globals["FooComponent"])
+      ({ desc: "notchHeight _ footer", ...__glintDSL__.NamedArgsMarker }));
+    __glintY__;
     {
-      const [] = 𝛄.blockParams["default"];
+      const [] = __glintY__.blockParams["default"];
       {
   // ...
 ```

packages/core/__tests__/transform/offset-mapping.test.ts

@@ -69,7 +69,7 @@ describe.skip('Transform: Source-to-source offset mapping', () => {
   }
 
   function findOccurrence(haystack: string, needle: string, occurrence: number): number {
-    let offset = haystack.indexOf('function(𝚪');
+    let offset = haystack.indexOf('function(__glintRef__');
     for (let i = 0; i < occurrence + 1; i++) {
       offset = haystack.indexOf(needle, offset + 1);