getTypeAtLocation crashes on the ImportClause of a type-only import

[lsh4711]

🔎 Search Terms

getTypeAtLocation ImportClause, type-only import crash, import type getTypeAtLocation nil pointer, tryGetDeclaredTypeOfSymbol, getDeclaredTypeOfSymbol panic

🕗 Version & Regression Information

• This is the behavior in every version I tried: 7.1.0-dev.20260926.1 (panics in the Go checker) and 6.0.3 (throws TypeError: Cannot read properties of undefined (reading 'flags')). The unguarded branch looks like it dates back to Type-only imports and exports #35200, which added type-only ImportClause to isTypeDeclaration.

⏯ Playground Link

No response

💻 Code

// types.ts
export type U = number;
// main.ts
import type { U } from "./types";
export const u: U = 1;

const clause = program.getSourceFile("main.ts").statements[0].importClause;
checker.getTypeAtLocation(clause);

🙁 Actual behavior

With TypeScript 7, the API server panics:

panic: runtime error: invalid memory address or nil pointer dereference
checker.(*Checker).tryGetDeclaredTypeOfSymbol
checker.(*Checker).getDeclaredTypeOfSymbol
checker.(*Checker).getTypeOfNode
checker.(*Checker).GetTypeAtLocation

With TypeScript 6.0.3, getTypeAtLocation throws TypeError: Cannot read properties of undefined (reading 'flags').

The same happens for import type * as ns from "./types". A regular import { U } from "./types" clause does not crash.

🙂 Expected behavior

getTypeAtLocation returns a type (the error type, like it does for a regular import clause) instead of crashing.

Additional information about the issue

I'm building syscript, a compiler that compiles TypeScript syntax to C for systems programming. It walks every node of a program and requests its type through the TypeScript 7 API, and that walk crashed on the first file that used import type.

isTypeDeclaration returns true for a type-only ImportClause, but a clause only has a symbol when it has a default binding, so getTypeOfNode passes a nil symbol to getDeclaredTypeOfSymbol. I have a fix with a test ready and will open a PR referencing this issue.