[labs/analyzer] Don't extract JSDoc types in TS. Port type tests to J…

…S. (#3658)

* TS already takes into account JSDoc comments when determining types, if applicable. (...)

When TypeScript is checking `.ts` files, JSDoc comments that indicate types have
no effect despite being parsed and reachable through the AST. When checking
`.js` files, JSDoc comments are automatically considered by `tsc` and don't need
to be separately taken into account.

* Remove incorrect JSDoc type tests. (...)

These tests were checking if types defined by JSDoc comments in `.ts` files were
being output by the analyzer. However, TS does not consider JSDoc comments to
have any effect in `.ts` files, even though they're parsed and reachable in the
AST.

* Copy TS type tests and port to JS.

* Remove a comment that no longer applies.

* Add a changeset.

.changeset/dry-ravens-drop.md

@@ -0,0 +1,5 @@
+---
+'@lit-labs/analyzer': minor
+---
+
+JSDoc types in TS files now have no effect on the analyzer's output, matching TS itself.

packages/labs/analyzer/src/lib/types.ts

@@ -60,13 +60,8 @@ export const getTypeForNode = (
   node: ts.Node,
   analyzer: AnalyzerInterface
 ): Type => {
-  // Since getTypeAtLocation will return `any` for an untyped node, to support
-  // jsdoc @type for JS (TBD), we look at the jsdoc type first.
-  const jsdocType = ts.getJSDocType(node);
   return getTypeForType(
-    jsdocType
-      ? analyzer.program.getTypeChecker().getTypeFromTypeNode(jsdocType)
-      : analyzer.program.getTypeChecker().getTypeAtLocation(node),
+    analyzer.program.getTypeChecker().getTypeAtLocation(node),
     node,
     analyzer
   );