Combine reducers with intersected type of unions causes tsc to crash

[rebyul]

TypeScript Version: 3.4.0-dev.201xxxxx
Typescript version: 3.4.5

Search Terms:
Redux combine reducers memory crash heap allocation

Code

// es6 import statements for actions and reducers

type FormActions = SignUpFormActionTypes &
  LoginFormActionTypes &
  ContactUsFormActionTypes &
  ForgotPasswordFormActionTypes &
  ResetPasswordFormActionTypes &
  CreateBusinessFormActionTypes &
  BusinessDetailsFormActionTypes &
  DealFormActionsTypes &
  InstantDealFormActionsTypes &
  JobListingFormActionTypes &
  OnlineLocationFormActionTypes &
  PhysicalLocationFormActionTypes;

export default combineReducers<FormsState, FormActions>({
  signUpForm: SignUpFormReducer,
  loginForm: LoginFormReducer,
  contactUsForm: ContactUsFormReducer,
  forgotPasswordForm: ForgotPasswordFormReducer,
  resetPasswordForm: ResetPasswordFormReducer,
  createBusinessForm: CreateBusinessFormReducer,
  businessDetailsForm: BusinessDetailsFormReducer,
  dealForm: DealFormReducer,
  instantDealForm: InstantDealFormReducer,
  jobListingForm: JobListingFormReducer,
  onlineLocationForm: OnlineLocationFormReducer,
  physicalLocationForm: PhysicalLocationFormReducer,
});

For example, an action type looks like this:

export type LoginFormActionTypes =
  | SubmitLoginAction
  | LoginSuccessAction
  | LoginFailedAction;

And each of those actions are plain javascript classes that implement from Action<> in the redux library

Expected behavior:
Should run tsc without issues

Actual behavior:
npx tsc

<--- Last few GCs --->

[59352:0000023E65B36200] 42665 ms: Mark-sweep 1391.2 (1425.2) -> 1390.9 (1425.7) MB, 966.8 / 0.0 ms (average mu = 0.081, current mu = 0.003) allocation failure scavenge might not succeed
[59352:0000023E65B36200] 43644 ms: Mark-sweep 1391.8 (1425.7) -> 1391.4 (1426.2) MB, 952.3 / 0.0 ms (average mu = 0.055, current mu = 0.027) allocation failure scavenge might not succeed

<--- JS stacktrace --->

==== JS stack trace =========================================

0: ExitFrame [pc: 000002A7DB3DC5C1]
1: StubFrame [pc: 000002A7DB3A26EE]

Security context: 0x030e7eb1e6e1
2: slice [0000030E7EB06D09](this=0x03034251dc11 <JSArray[12]>,0)
3: /* anonymous /(aka / anonymous */) [000003034251DCC9] [D:\Workspace\business-portal\node_modules\typescript\lib\tsc.js:~33214] [pc=000002A7DC4AFFD1](this=0x0054b7c826f1 ,t=0x0074346aaf91 )
4: argu...

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
1: 00007FF79DD9ECF5
2: 00007FF79DD781A6
3: 00007FF79DD78BB0
4: 00007FF79E009AAE
5: 00007FF79E0099DF
6: 00007FF79E547724
7: 00007FF79E53DE87
8: 00007FF79E53C3FC
9: 00007FF79E545377
10: 00007FF79E5453F6
11: 00007FF79E0E84B7
12: 00007FF79E18019A
13: 000002A7DB3DC5C1

When I replace the action type of combineReducers to combineReducers<FormsState, any>, tsc runs and webpack compiles with linting.

These are my compiler options in tsconfig

"compilerOptions: {
    "outDir": "dist",
    "sourceMap": true,
    "allowSyntheticDefaultImports": true,
    "declaration": false,
    "noFallthroughCasesInSwitch": true,
    "importHelpers": true,
    "noEmitHelpers": true,
    "noImplicitAny": true,
    "skipLibCheck": true,
    "strictNullChecks": true,
    "noImplicitThis": true,
    "alwaysStrict": true,
    "isolatedModules": true,
    "allowJs": true,
    "checkJs": true,
    "module": "es2015",
    "noImplicitReturns": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "strict": true,
    "pretty": true,
    "removeComments": true,
    "target": "es5",
    "jsx": "react"
}

When I remove two or more declared action(s) that are part of the intersected FormActions type, tsc compiles again.

Related Issues:

[ajafff]

How can one reproduce this without knowing the types of your Actions and Reducers?

Also please fix the formatting of the opening post. It's a pain to read.

[rebyul]

Apologies for the formatting, I've updated the opening post.
Actions are es6 classes implementing Action from redux
e.g.

export default class ExampleAction implements Action<ActionKeys> {
  readonly type = ActionKeys.CreateDeal;
}

and reducers are typed with Reducer<S, A> from redux

e.g.

const SampleReducer: Reducer<
  SampleState,
  SampleActions
> = (
  state: SampleState= new SampleState(),
  action: SampleActions
) => {
    // switch statements
    return state;
}

[weswigham]

But, like, just how many members are in each union you're trying to intersect here?

[rebyul]

Each of the intersections have 2~6 action types, 50 total actions included in the total union.
Apologies for not being able to upload the code, I will try get around to creating a sandbox later today.

[weswigham]

6^12 is about 2 billion possible alternatives, soooooooooo

50 total actions included in the total union

You've got an intersection listed up there, not a union? Is that intentional?

[rebyul]

https://github.com/rebyul/tsmemalloc

Sorry this took so long, I had a deadline due last week and had to chug through without typing my reducers.

The linked repository isn't able to replicate the OOM issue that I am having, and I am unable to invest more time into creating a bigger project to trigger an OOM exception. It is somewhat close to how I have my reducers set up (multiple base level reducers with some nested reducers. The tsc diagnostics looks like this:

• Files: 93
• Lines: 66899
• Nodes: 191573
• Identifiers: 62754
• Symbols: 99624
• Types: 814246
• Memory used: 856780K
• I/O read: 0.04s
• I/O write: 0.00s
• Parse time: 0.65s
• Bind time: 0.42s
• Check time: 14.61s
• Emit time: 0.00s
• Total time: 15.68s

I could feel the intellisense getting significantly slower after adding the IFormState interface with reference to the Formik library. I apologize for the lack of information I have provided.

You've got an intersection listed up there, not a union? Is that intentional?

I apologize, it is an intersection; I would have thought it should be a union but the combineReducers function gives compilation errors if its changed to a union.

Also, on my repo that is having the OOM issues, running tsc --diagnostics has the followering values:

• Files: 6299
• Lines: 164873
• Nodes: NaN
• Identifiers: NaN
• Symbols: 417223
• Types: 234298
• Memory used: 592309K
• I/O read: 0.79s
• I/O write: 0.26s
• Parse time: 5.78s
• Bind time: 1.29s
• Check time: 18.34s
• Emit time: 2.44s
• Total time: 27.85s

There is a related issue on DefinitelyTyped https://github.com/DefinitelyTyped/DefinitelyTyped/issues/35514 which seems to be having similar issues.

[amcasey]

I have no recollection of why this ceased to be Needs Investigation or why I grabbed it.