types: add generics to Transaction (#38)

bangle-io · Oct 7, 2023 · 840fe30 · 840fe30
1 parent e3f55d7
commit 840fe30
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Showing 8 changed files with 20 additions and 13 deletions.
diff --git a/packages/core/src/base-store.ts b/packages/core/src/base-store.ts
@@ -4,7 +4,7 @@ import type { StoreState } from './store-state';
 import type { Transaction } from './transaction';
 
 export type Dispatch = (
-  txn: Transaction | Operation,
+  txn: Transaction<any, any> | Operation,
   opts?: {
     debugInfo?: string;
   },
@@ -16,5 +16,5 @@ export abstract class BaseStore {
   // @internal
   abstract _rootStore: Store<any>;
 
-  abstract dispatch(txn: Transaction | Operation): void;
+  abstract dispatch(txn: Transaction<any, any> | Operation): void;
 }
diff --git a/packages/core/src/effect/effect.ts b/packages/core/src/effect/effect.ts
@@ -41,7 +41,7 @@ export class EffectStore<TSliceName extends string = any> extends BaseStore {
     return this._rootStore.state;
   }
 
-  dispatch(txn: Transaction | Operation) {
+  dispatch(txn: Transaction<any, any> | Operation) {
     this._rootStore.dispatch(txn);
   }
 }

diff --git a/packages/core/src/effect/operation.ts b/packages/core/src/effect/operation.ts
@@ -28,7 +28,7 @@ export class OperationStore extends BaseStore {
     return this.rootStore.state;
   }
 
-  dispatch(txn: Transaction | Operation) {
+  dispatch(txn: Transaction<any, any> | Operation) {
     this.rootStore.dispatch(txn);
   }
 

diff --git a/packages/core/src/slice/field.ts b/packages/core/src/slice/field.ts
@@ -117,7 +117,7 @@ export class StateField<
       ._getFieldStateVal(this) as TVal;
   }
 
-  update(val: TVal | ((val: TVal) => TVal)): Transaction {
+  update(val: TVal | ((val: TVal) => TVal)): Transaction<TName, TDep> {
     const txn = this.key.transaction();
 
     return txn.step((state: StoreState<any>) => {

diff --git a/packages/core/src/slice/key.ts b/packages/core/src/slice/key.ts
@@ -63,7 +63,7 @@ export class Key<TName extends string, TDepName extends string> {
     actions,
   }: {
     fields: TFieldsSpec;
-    actions?: (...args: any) => Transaction;
+    actions?: (...args: any) => Transaction<TName, TDepName>;
   }): Slice<TFieldsSpec, TName, TDepName> {
     if (this._slice) {
       throwValidationError(
@@ -80,7 +80,7 @@ export class Key<TName extends string, TDepName extends string> {
    * Creates a new transaction object which is used to update the slice state.
    */
   transaction() {
-    return new Transaction();
+    return new Transaction<TName, TDepName>();
   }
 
   // @internal

diff --git a/packages/core/src/store-state.ts b/packages/core/src/store-state.ts
@@ -71,7 +71,8 @@ export class StoreState<TSliceName extends string> {
     private config: StoreStateConfig,
   ) {}
 
-  apply(transaction: Transaction): StoreState<TSliceName> {
+  // TODO: add strict type checking to Txn.
+  apply(transaction: Transaction<any, any>): StoreState<TSliceName> {
     if (transaction._isDestroyed()) {
       throwValidationError(
         `Transaction "${transaction.id}" has already been applied.`,

diff --git a/packages/core/src/store.ts b/packages/core/src/store.ts
@@ -40,7 +40,7 @@ export const DEFAULT_DISPATCH_TRANSACTION: DispatchTransaction<any> = (
 type DispatchTransaction<TSliceName extends string> = (
   store: Store<TSliceName>,
   updateState: (state: StoreState<TSliceName>) => void,
-  tx: Transaction,
+  tx: Transaction<any, any>,
 ) => void;
 
 export function createStore<TSliceName extends string>(
@@ -112,7 +112,7 @@ export class Store<TSliceName extends string> extends BaseStore {
     });
   }
 
-  dispatch(transaction: Transaction | Operation): void {
+  dispatch(transaction: Transaction<any, any> | Operation): void {
     if (this.destroyed) {
       return;
     }

diff --git a/packages/core/src/transaction.ts b/packages/core/src/transaction.ts
@@ -1,12 +1,14 @@
 import { genTransactionID } from './helpers/id-generation';
 import type { StoreState } from './store-state';
 
-type Step = { stepper: (storeState: StoreState<any>) => StoreState<any> };
+type Step<TName extends string = any> = {
+  stepper: (storeState: StoreState<TName>) => StoreState<TName>;
+};
 
 export const META_DISPATCHER = 'DEBUG__DISPATCHER';
 export const TX_META_STORE_NAME = 'store-name';
 
-export class Transaction {
+export class Transaction<TName extends string, TDepName extends string> {
   readonly id = genTransactionID();
   readonly metadata = new Metadata();
 
@@ -25,7 +27,11 @@ export class Transaction {
     return this.steps;
   }
 
-  step(stepper: Step['stepper']): Transaction {
+  step(
+    // merge both TName and TDepName into one type, so its easier to use
+    // with StoreState
+    stepper: Step<TName | TDepName>['stepper'],
+  ): Transaction<TName, TDepName> {
     this.steps.push({ stepper });
     return this;
   }