Poor error message when names conflict

[OliverJAsh]

TypeScript Version: 3.5.2

Search Terms: debug failure unexpected node error message exception

Obviously the following code is incorrect, however I would expect a friendly error message directing the user to the problem, rather than the nasty/ambiguous error message that is currently given: Error: Debug Failure. Unexpected node.

I ran into this in a large codebase and it took me awhile to find source of the problem.

Code

yarn add @types/lodash

import * as pick from 'lodash/pick';

export const pick = () => pick();

$ tsc

/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:73748
                throw e;
                ^

Error: Debug Failure. Unexpected node.
Node 156 was unexpected.
    at getDeclarationSpaces (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:46074:41)
    at /Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:46066:84
    at Object.forEach (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:217:30)
    at getDeclarationSpaces (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:46066:28)
    at checkExportsOnMergedDeclarations (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:46009:41)
    at checkVariableLikeDeclaration (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:47011:17)
    at checkVariableDeclaration (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:47048:20)
    at checkSourceElementWorker (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:48787:28)
    at checkSourceElement (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:48648:17)
    at Object.forEach (/Users/oliverjash/Development/typescript-playground/node_modules/typescript/lib/tsc.js:217:30)

[fatcerberus]

Error: Debug Failure. Unexpected node

🐞
That's not a normal error message. The compiler actually crashed. It's 100% a bug. 😄

[sandersn]

What version of lodash is this?

[sandersn]

repros with @types/lodash@4.14.136. The unexpected node kind is MethodSignature, which probably has something to do with following an alias along until the original pick method is encountered.

[sandersn]

Starting failing this way in 2.6.

[captain-yossarian]

I have same error:
ERROR in [internal] INTERNAL ERROR: Debug Failure. Unexpected node. Node Identifier was unexpected. stack trace: Error: Debug Failure. Unexpected node. Node Identifier was unexpected. at getDeclarationSpaces (app\node_modules\type script\lib\typescript.js:59394:41) at checkExportsOnMergedDeclarations (app\node_ modules\typescript\lib\typescript.js:59320:41) at checkVariableLikeDeclaration (app\node_modu les\typescript\lib\typescript.js:60568:17) at checkVariableDeclaration (app\node_modules\ typescript\lib\typescript.js:60606:20) at checkSourceElementWorker (app\node_modules\ typescript\lib\typescript.js:63058:28) at checkSourceElement (app\node_modules\typesc ript\lib\typescript.js:62912:17) at Object.forEach (app\node_modules\typescript \lib\typescript.js:309:30) at checkVariableStatement (app\node_modules\ty pescript\lib\typescript.js:60616:16) at checkSourceElementWorker (app\node_modules\ typescript\lib\typescript.js:63027:28) at checkSourceElement (app\node_modules\typesc ript\lib\typescript.js:62912:17)

after migration from 3.5.3 to 3.7.4.
And I have no clue which package triggers this error, because project is big

[captain-yossarian]

@sandersn I think I've figured out why this error happens, at least in my code.
My code:

/**
 * @typedef (Object) CustomProps
 * @property (Boolean) visible
 * @property (children:React.ReactNode) children
 *
 * @param {CustomProps} props
 */
const SomeComponent=(props)=><div>Hello</div>;

As you see, there is invalid JSDoc syntax.
TS compiler crashed here typescript\lib\typescript.js:59394.

// d.kind = 75, SyntaxKind.Identifier
return ts.Debug.failBadSyntaxKind(d)

After JSDoc code was fixed, the error is gone.
I hope it will help.

[joeprivettsmart]

I'm getting a similar error, though not speicific to lodash:

/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70731
                    return ts.Debug.failBadSyntaxKind(node);
                                    ^
Error: Debug Failure. Unexpected node.
Node 193 was unexpected.
    at serializeTypeNode (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70731:37)
    at serializeTypeOfNode (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70594:28)
    at addOldTypeMetadata (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70536:97)
    at addTypeMetadata (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70530:17)
    at transformAllDecoratorsOfDeclaration (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70447:13)
    at generateClassElementDecorationExpression (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70472:40)
    at generateClassElementDecorationExpressions (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70458:34)
    at addClassElementDecorationStatements (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70451:44)
    at visitClassDeclaration (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70252:13)
    at visitTypeScript (/Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js:70137:28)

How do I even start to debug this?

[sandersn]

@joeprivettsmart If you can get this caught in the debugger, you can probably find a SourceFile object somewhere in the stack and inspect its name.

Basically, node --inspect-brk /Users/joe.privett/Sources/cms/node_modules/typescript/lib/tsc.js, then put a breakpoint in serializeTypeNode on the ts.Debug.failBadSyntaxKind.

The alternative is "binary debugging", in which you delete half of your files at a time to see which ones had the bad node.

Either way, I'm pretty sure it's in a file with decorators because that's serializeTypeNode says that it converts type nodes to their equivalent runtime types.

It would be a good idea to open a new bug while you're at it, because your stack is quite different from the original one.

[Andarist]

The test case for the original issue reported by @OliverJAsh here:

// @strict: true
// @noEmit: true

// @filename: node_modules/@types/lodash/object.d.ts
import _ = require("./index");
declare module "./index" {
    interface LoDashStatic {
      pick<T extends object, U extends keyof T>(
        object: T,
        ...props: Array<U>
      ): Pick<T, U>;
    }
}

// @filename: node_modules/@types/lodash/pick.d.ts
import { pick } from "./index";
export = pick;

// @filename: node_modules/@types/lodash/index.d.ts

/// <reference path="./object.d.ts" />
export = _;
export as namespace _;
declare const _: _.LoDashStatic;
declare namespace _ {
    interface LoDashStatic {}
}

// @filename: index.ts
import * as pick from 'lodash/pick';
export const pick = () => pick();