fix(observable): add explicit extensions to relative ESM imports

Relative import/export specifiers in @equinor/fusion-observable's source
lacked file extensions (e.g. './operators' instead of './operators/index.js').
Under the package's inherited moduleResolution: bundler tsconfig, tsc never
adds them, so the compiled ESM output only resolves for bundler-based
consumers. Consumers resolving the published dist directly under strict
Node.js ESM (e.g. vitest without a bundler) fail with module-not-found errors.

Add explicit .js/.js/index.js extensions to every relative import/export in
src, and override the package's own tsconfig to module/moduleResolution:
nodenext so tsc enforces this going forward instead of silently regressing.

Author: odinr

.changeset/observable_fix-esm-import-extensions.md

@@ -0,0 +1,5 @@
+---
+"@equinor/fusion-observable": patch
+---
+
+Fix relative import/export specifiers in the published ESM output missing file extensions (e.g. `./operators` instead of `./operators/index.js`). This broke strict Node.js ESM resolution for consumers not using a bundler (e.g. `vitest` running against `node_modules` directly), producing errors like `Cannot find module '.../operators'`.

packages/utils/observable/src/FlowSubject.ts

@@ -17,11 +17,11 @@ import {
   observeOn,
   scan,
 } from 'rxjs/operators';
-import { filterAction } from './operators';
+import { filterAction } from './operators/index.js';
 
-import type { Action, ActionType, ExtractAction } from './actions/types';
-import type { Flow, Effect } from './types/flow';
-import type { ReducerWithInitialState } from './types/reducers';
+import type { Action, ActionType, ExtractAction } from './actions/types.js';
+import type { Flow, Effect } from './types/flow.js';
+import type { ReducerWithInitialState } from './types/reducers.js';
 
 /**
  * A specialized Observable that maintains internal state mutated by dispatching actions.

packages/utils/observable/src/actions/ActionError.ts

@@ -1,4 +1,4 @@
-import type { Action } from './types';
+import type { Action } from './types.js';
 
 /**
  * An error class that wraps a causal error together with the action that triggered it.

packages/utils/observable/src/actions/action-mapper.ts

@@ -1,4 +1,4 @@
-import type { ActionCreator, ActionDefinitions, ActionTypes } from './types';
+import type { ActionCreator, ActionDefinitions, ActionTypes } from './types.js';
 
 /**
  * A mapped type that converts {@link ActionDefinitions} into an object of

packages/utils/observable/src/actions/create-action.ts

@@ -4,13 +4,13 @@
  * taken from https://github.com/reduxjs/redux-toolkit/tree/master/packages/toolkit/src
  */
 
-import type { Action, PayloadAction } from './types';
+import type { Action, PayloadAction } from './types.js';
 import type {
   IfMaybeUndefined,
   IfVoid,
   IsAny,
   IsUnknownOrNonInferrable,
-} from '../types/ts-helpers';
+} from '../types/ts-helpers.js';
 
 /**
  * A "prepare" method to be used as the second parameter of `createAction`.
@@ -269,7 +269,7 @@ export function createAction(type: string, prepareAction?: PrepareAction<any>):
   return actionCreator;
 }
 
-export { actionSuffixDivider, matchActionSuffix, getBaseType, getType } from './utils';
+export { actionSuffixDivider, matchActionSuffix, getBaseType, getType } from './utils.js';
 
 // helper types for more readable typings
 

packages/utils/observable/src/actions/create-async-action.ts

@@ -1,16 +1,16 @@
 // biome-ignore-all lint/suspicious/noExplicitAny: generic constraints mirror create-action.ts's ported redux-toolkit PrepareAction<any> dispatch pattern
 
-import { actionSuffixDivider, createAction } from './create-action';
+import { actionSuffixDivider, createAction } from './create-action.js';
 import {
   isActionWithSuffix,
   isCompleteAction,
   isFailureAction,
   isRequestAction,
   isSuccessAction,
-} from './predicates';
-import type { PayloadActionCreator } from './create-action';
+} from './predicates.js';
+import type { PayloadActionCreator } from './create-action.js';
 
-import type { PrepareAction } from './create-action';
+import type { PrepareAction } from './create-action.js';
 
 /**
  * Creates an async action creator that produces request, success, and optionally failure sub-actions.

packages/utils/observable/src/actions/index.ts

@@ -6,7 +6,7 @@
  *
  * @module actions
  */
-export * from './ActionError';
+export * from './ActionError.js';
 export * from './types.js';
 
 export { actionMapper, type ActionCalls } from './action-mapper.js';
@@ -19,7 +19,7 @@ export {
   type ActionCreatorWithOptionalPayload,
   type ActionCreatorWithPreparedPayload,
   type PayloadActionCreator,
-} from './create-action';
+} from './create-action.js';
 
 export { getBaseType } from './utils.js';
 
@@ -29,4 +29,4 @@ export {
   isCompleteAction,
   isFailureAction,
   isSuccessAction,
-} from './create-async-action';
+} from './create-async-action.js';

packages/utils/observable/src/actions/predicates.ts

@@ -1,5 +1,5 @@
-import type { Action, ActionWithSuffix, AnyAction } from './types';
-import { matchActionSuffix } from './utils';
+import type { Action, ActionWithSuffix, AnyAction } from './types.js';
+import { matchActionSuffix } from './utils.js';
 
 /**
  * Checks whether an action type ends with a specific lifecycle suffix.

packages/utils/observable/src/actions/utils.ts

@@ -1,4 +1,4 @@
-import type { PayloadActionCreator } from './create-action';
+import type { PayloadActionCreator } from './create-action.js';
 
 /**
  * Internal helper utilities for constructing and inspecting Redux-style

packages/utils/observable/src/create-reducer.ts

@@ -2,9 +2,9 @@ import { produce as createNextState, isDraft, isDraftable } from 'immer';
 
 import type { Draft } from 'immer';
 
-import type { TypeGuard } from './types/ts-helpers';
-import type { Action, ActionType, AnyAction, ExtractAction } from './actions/types';
-import type { ReducerWithInitialState } from './types/reducers';
+import type { TypeGuard } from './types/ts-helpers.js';
+import type { Action, ActionType, AnyAction, ExtractAction } from './actions/types.js';
+import type { ReducerWithInitialState } from './types/reducers.js';
 
 function freezeDraftable<T>(val: T) {
   return isDraftable(val) ? createNextState(val, () => {}) : val;