Native printer panics when printing JSDoc AST nodes #65057

🔎 Search Terms

emitJSDocNode, "not implemented", printer JSDoc, printNode JSDoc, JSDoc AST node panic

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about this. It reproduces on current main of the native (Go) compiler: Printer.emitJSDocNode is still a stub.

⏯ Playground Link

N/A. This is about the native Go printer and the TypeScript 7 JS API (api.printer.printNode), which the Playground does not exercise.

💻 Code

// Using the native API: create a JSDoc node with the factory and print it directly.
const doc = factory.createJSDocComment(
    "Adds two numbers.",
    factory.createNodeArray([
        factory.createJSDocParameterTag(
            factory.createJSDocTag(factory.createIdentifier("param"), undefined),
            factory.createIdentifier("a"),
            false,
        ),
    ]),
);
api.printer.printNode(doc); // panics

The same crash occurs for any JSDoc node kind that the printer dispatches to Printer.emitJSDocNode.

🙁 Actual behavior

The printer dispatches JSDoc node kinds to Printer.emitJSDocNode in tsc/internal/printer/printer.go, which is currently:

func (p *Printer) emitJSDocNode(node *ast.Node) {
	// !!!
	panic("not implemented")
}

so printing a JSDoc node panics.

🙂 Expected behavior

The printer should emit a formatted JSDoc comment, including its text and tags, like it does for other node kinds.

Additional information about the issue

I searched open and closed issues and PRs for this and found no other report or PR that implements JSDoc node emission. Open PR #64500 (synthetic comments and emit flags in the API) is related but does not implement emitJSDocNode.

I have a focused fix that I will link here as a PR. Sorry for the missing template in the first version of this issue, and thanks for pointing it out.