v5.5.4 regression "Error: Debug Failure. False expression." when using incremental const x = { ...({} as { [K in keyof { someKey?: any }]?: undefined }) }

[700software]

🔎 Search Terms Description

Ran into this hard to find bug crashing our production build. It was difficult to get a Minimal Reproducible Example for you but after hours of work I finally narrowed it down. Check it out!

Using combination of

• { "compilerOptions": { "incremental": true } }
• npm install -D @types/node done after tsconfig.tsbuildinfo already exists
  • Note: This particular sequence is not required for production repro but is the only way I could get this Minimal Reproducible Example for sake of opening this issue. In production, of course, tsconfig.tsbuildinfo is absent on every build to keep things fresh. :)
• runtime object expansion
• wrapper type to
  • make properties optional
  • make properties undefined
• avoid using as const

Am getting crash of typescript build.

Changing any one of these 6 things causes the crash to go away.

🕗 Version & Regression Information

Works fine in 5.5.3
Broken in 5.5.4 & 5.6.3 & 5.7.0-beta

⏯ Playground Link

No repro because incremental checkbox not in playground.

💻 Code

test.ts

type InputType = { enable_member_receipts?: boolean };
type AsEmptyObject<T> = { [K in keyof T]?: undefined }; // This is a utility type we use internally.

const test = {
  // ...

  ...({} as AsEmptyObject<InputType>),
}; // omit `as const`

tsconfig.json

{
  "compilerOptions": {
    "incremental": true,
  }
}

🙁 Actual behavior

PS C:\GitHub\tmp\repro-ts-bug> tsc --noEmit
C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:120986
      throw e;
      ^

Error: Debug Failure. False expression.
    at getOptionalType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:66203:11)
    at tryReuseExistingTypeNode (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:49675:16)
    at serializeTypeForDeclaration (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:51693:61)
    at addPropertyToElementList (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50663:43)
    at createTypeNodesFromResolvedType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50559:11)
    at createTypeNodeFromObjectType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50334:25)
    at visitAndTransformType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50257:24)
    at createAnonymousTypeNode (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50197:20)
    at typeToTypeNodeWorker (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:49990:16)
    at typeToTypeNodeHelper (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:49771:24)

Node.js v22.8.0
PS C:\GitHub\tmp\repro-ts-bug>

🙂 Expected behavior

PS C:\GitHub\tmp\repro-ts-bug> tsc --noEmit
PS C:\GitHub\tmp\repro-ts-bug>

Additional information about the issue

I needed this specific sequence to repro:

PS C:\GitHub\tmp\repro-ts-bug> rm -r -Path node_modules, package.json, package-lock.json, tsconfig.tsbuildinfo
PS C:\GitHub\tmp\repro-ts-bug> npm install -D [email protected]

added 1 package in 657ms
PS C:\GitHub\tmp\repro-ts-bug> tsc --noEmit
PS C:\GitHub\tmp\repro-ts-bug> npm install @types/[email protected]

added 2 packages, and audited 4 packages in 863ms

found 0 vulnerabilities
PS C:\GitHub\tmp\repro-ts-bug> tsc --noEmit
C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:120986
      throw e;
      ^

Error: Debug Failure. False expression.
    at getOptionalType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:66203:11)
    at tryReuseExistingTypeNode (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:49675:16)
    at serializeTypeForDeclaration (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:51693:61)
    at addPropertyToElementList (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50663:43)
    at createTypeNodesFromResolvedType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50559:11)
    at createTypeNodeFromObjectType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50334:25)
    at visitAndTransformType (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50257:24)
    at createAnonymousTypeNode (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:50197:20)
    at typeToTypeNodeWorker (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:49990:16)
    at typeToTypeNodeHelper (C:\GitHub\tmp\repro-ts-bug\node_modules\typescript\lib\tsc.js:49771:24)

Node.js v22.8.0
PS C:\GitHub\tmp\repro-ts-bug>

Replace [email protected] with the version you desire to test.

[Andarist]

duplicate of #60390

fourslash test:

// @strictNullChecks: false
// @declaration: true
// @emitDeclarationOnly: true

type InputType = { enable_member_receipts?: boolean };
type AsEmptyObject<T> = { [K in keyof T]?: undefined };

export const test = {
  ...({} as AsEmptyObject<InputType>),
};