Stack overflow related to "getting" awaited, recursive union type

[DuncanWalter]

Bug Report

Hit a stack overflow that seems like a member of this family of previously reported + solved issue.

🔎 Search Terms

stack limit mapType getAwaitedType getAwaitedTypeWorker

🕗 Version & Regression Information

Seems to have existed since ~3.7 when the type keyword began to support self references. The playground link is for the nightly. I had to open the dev tools to see the actual crash message in the playground.

⏯ Playground Link

Playground link with relevant code

💻 Code

type EffectResult =
  | (() => EffectResult)
  | Promise<EffectResult>;

export async function handleEffectResult(result: EffectResult) {
  if (result instanceof Function) { 
    await handleEffectResult(result());
  } else if (result instanceof Promise) { 
    await handleEffectResult(await result); 
  }
}

🙁 Actual behavior

RangeError: Maximum call stack size exceeded
    at /absolute-path/node_modules/typescript/lib/tsc.js:59379:52
    at mapType (/absolute-path/node_modules/typescript/lib/tsc.js:50800:30)
    at getAwaitedType (/absolute-path/node_modules/typescript/lib/tsc.js:59379:17)
    at getAwaitedTypeWorker (/absolute-path/node_modules/typescript/lib/tsc.js:59395:35)
    at /absolute-path/node_modules/typescript/lib/tsc.js:59379:79
    at mapType (/absolute-path/node_modules/typescript/lib/tsc.js:50800:30)
    at getAwaitedType (/absolute-path/node_modules/typescript/lib/tsc.js:59379:17)
    at getAwaitedTypeWorker (/absolute-path/node_modules/typescript/lib/tsc.js:59395:35)
    at /absolute-path/node_modules/typescript/lib/tsc.js:59379:79
    at mapType (/absolute-path/node_modules/typescript/lib/tsc.js:50800:30)
error Command failed with exit code 1.

🙂 Expected behavior

In hindsight that code is pretty sadistically self-referential, but I didn't expect to hit an overflow limit. Ideally the code sample should check without any issue. Alternatively, some warning to indicate which lines of code are involved in process crash would be plenty; this type of nightmare-recursion should be an edge case, and there's a decent workaround. This edited sample is fine for the same range of versions from 3.7 to the nightly build:

type Effect = () => EffectResult

type EffectResult =
  | Effect
  | Promise<Effect>;

export async function handleEffectResult(result: EffectResult) {
  if (result instanceof Function) { 
    await handleEffectResult(result());
  } else if (result instanceof Promise) { 
    await handleEffectResult(await result); 
  }
}

Thanks in advance for taking a look 😄

[akutruff]

Hitting a stack overflow too. It's not promise related, but maybe this call stack helps. My code is also heavily self-referential and heavily uses recursive conditional types

Compiled with 4.2.3

/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:88055
                throw e;
                ^
RangeError: Maximum call stack size exceeded
    at createBaseNode (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:16664:32)
    at Object.createInferTypeNode (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:17463:24)
    at typeToTypeNodeHelper (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39163:43)
    at mapToTypeNodes (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39674:40)
    at typeReferenceToTypeNode (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39462:49)
    at typeToTypeNodeHelper (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39158:95)
    at typeToTypeNodeHelper (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39227:43)
    at mapToTypeNodes (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39674:40)
    at typeToTypeNodeHelper (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39150:45)
    at typeToTypeNodeOrCircularityElision (/usr/local/share/npm-global/lib/node_modules/typescript/lib/tsc.js:39250:28)

[DanielRosenwasser]

Thanks @Andarist!