Combine reducers with intersected type of unions causes tsc to crash

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 <JSObject> 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 <undefined>,t=0x0074346aaf91 <Type map = 0000002A182ED9C9>) 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.

[amcasey]

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