feat(data-loader): pass loader context to loadMany (#36)

This allows loaders to reference other loaders
SeedCompany · Sep 17, 2024 · d7b2851 · d7b2851
1 parent af90dbe
commit d7b2851
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Showing 3 changed files with 11 additions and 5 deletions.
diff --git a/packages/data-loader/src/data-loader.context.ts b/packages/data-loader/src/data-loader.context.ts
@@ -58,16 +58,17 @@ export class DataLoaderContext {
  });
  }
 
- private createContext(): LoaderContextType {
+ private createContext() {
  const contextId = ContextIdFactory.create();
  const loaders: LoaderContextType['loaders'] = new Map();
- return {
+ const loaderContext: LoaderContextType = {
  contextId,
  loaders,
  getLoader: cacheable(loaders, (strategyType) =>
- this.factory.create(strategyType, contextId),
+ this.factory.create(strategyType, contextId, loaderContext),
  ),
  };
+ return loaderContext;
  }
 }
 

diff --git a/packages/data-loader/src/data-loader.factory.ts b/packages/data-loader/src/data-loader.factory.ts
@@ -2,6 +2,7 @@ import { Inject, Injectable, Type } from '@nestjs/common';
 import { ContextId, ModuleRef } from '@nestjs/core';
 import DataLoaderLib from 'dataloader';
 import type { DataLoaderOptions } from './data-loader-options.type';
+import type { LoaderContextType } from './data-loader.context';
 import { MODULE_OPTIONS_TOKEN } from './data-loader.module-builder';
 import { DataLoaderStrategy } from './data-loader.strategy';
 import { DataLoader } from './data-loader.type';
@@ -27,6 +28,7 @@ export class DataLoaderFactory {
  async create<Item, Key, CachedKey = Key>(
  strategyType: Type<DataLoaderStrategy<Item, Key, CachedKey>>,
  contextId: ContextId,
+ loaderContext: LoaderContextType,
  ): Promise<DataLoader<Item, Key, CachedKey>> {
  const strategy = await this.moduleRef.resolve<
  DataLoaderStrategy<Item, Key, CachedKey>
@@ -35,7 +37,7 @@ export class DataLoaderFactory {
  const options = this.resolveOptions(strategy, this.defaultOptions);
 
  const loader = new DataLoaderLib<Key, Item, CachedKey>(
- this.makeBatchFn(strategy, options),
+ this.makeBatchFn(strategy, options, loaderContext),
  options,
  ) as DataLoader<Item, Key, CachedKey>;
 
@@ -72,11 +74,12 @@ export class DataLoaderFactory {
  protected makeBatchFn<Item, Key, CachedKey = Key>(
  strategy: DataLoaderStrategy<Item, Key, CachedKey>,
  options: ResolvedDataLoaderOptions<Item, Key, CachedKey>,
+ loaderContext: LoaderContextType,
  ) {
  const { propertyKey: getKey, cacheKeyFn: getCacheKey } = options;
 
  const batchFn: DataLoaderLib.BatchLoadFn<Key, Item> = async (keys) => {
- const docs = await strategy.loadMany(keys);
+ const docs = await strategy.loadMany(keys, loaderContext);
 
  // Put documents (docs) into a map where key is a document's ID or some
  // property (prop) of a document and value is a document.

diff --git a/packages/data-loader/src/data-loader.strategy.ts b/packages/data-loader/src/data-loader.strategy.ts
@@ -1,9 +1,11 @@
 /* eslint-disable @typescript-eslint/method-signature-style */
 import { DataLoaderOptions } from './data-loader-options.type';
+import { LoaderContextType } from './data-loader.context';
 
 export interface DataLoaderStrategy<Item, Key, CachedKey = Key> {
  loadMany(
  keys: readonly Key[],
+ loaderContext: LoaderContextType,
  ): Promise<ReadonlyArray<Item | { key: Key; error: Error }>>;
 
  getOptions?: () => DataLoaderOptions<Item, Key, CachedKey>;