Namespace import in esm for cjs module described by `any` type leads to debug failure

[dsherret]

Bug Report

Namespace importing a cjs module described with an any type from an es module leads to a debug failure.

🔎 Search Terms

Debug Failure. Unhandled type 1

🕗 Version & Regression Information

• This is a crash in 4.9.0-dev.20221007 and 4.8.4

⏯ Playground Link

Can't because it's multiple files.

💻 Code

package.json

{
  "name": "test",
  "version": "1.0.0",
  "description": "",
  "type": "module",
  "module": "index.mjs",
  "dependencies": {
    "typescript": "^4.9.0-dev.20221007"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "target": "ESNext",
    "module": "ESNext",
    "moduleResolution": "NodeNext",
    "strict": true
  }
}

index.mts

import * as namespaceImport from "./other.cjs";
console.log(namespaceImport);

other.cjs

// note: this is described by other.d.cts
module.exports.test = () => 5;

other.d.cts

declare const __: any;
export = __;

🙁 Actual behavior

Running tsc:

V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:99472
                throw e;
                ^

Error: Debug Failure. Unhandled type 1
    at resolveStructuredTypeMembers (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:49660:30)
    at cloneTypeAsModuleType (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:43230:38)
    at resolveESModuleSymbol (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:43209:36)
    at getTargetOfNamespaceImport (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:42412:28)
    at getTargetOfAliasDeclaration (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:42640:28)
    at resolveAlias (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:42681:30)
    at checkAliasSymbol (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:72981:26)
    at checkImportBinding (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:73096:13)
    at checkImportDeclaration (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:73147:29)
    at checkSourceElementWorker (V:\any-cjs-tsc\node_modules\typescript\lib\tsc.js:73614:28)

Note: type 1 is TypeFlags.Any

🙂 Expected behavior

Should pass type checking.

Why?

We use the file with declare const __: any; export = __ in Deno in order to give certain modules an any type. Now when adding impliedNodeFormat when creating a source file in order to allow importing npm packages, I had to make this module CJS because it has export = and that surfaced this issue.

[jakebailey]

I can reproduce this, but the bisect will certainly show this to be #49943 where I added the assert.

any is not a StructuredType so it's not right for any to be there; cloneTypeAsModuleType casts the module type to StructuredType so this fits with the bug. Probably, it should check if the export is actually a structured type; it only cares because it aims to remove the call signatures from said type but that's not helpful when the type is already any.

[jakebailey]

Also, the same thing happens when the export is unknown, symbol, etc, for the same reason.

[jakebailey]

I should note that I also don't know the semantics of this:

    "target": "ESNext",
    "module": "ESNext",
    "moduleResolution": "NodeNext",

As that's something we have a PR to actively ban (#50985), but I don't know if that affects this issue.

I'm not really sure off the top of my head what you can actually get as an export object when it's a * import; can it only ever be an structured object and not say, symbol?

[jakebailey]

I opened #51136 since I had the code, but I think someone with better knowledge about the workings of these kinds of imports should weigh in. (I'm getting to this pre-triage, sorry!)