Consolidate fake db interface and table

Also more tests

Author: mikebroberts

packages/dynamodb-entity-store-testutils/src/fakeDynamoDBInterface.ts

@@ -6,6 +6,7 @@ import {
   DeleteCommandInput,
   GetCommandInput,
   GetCommandOutput,
+  NativeAttributeValue,
   PutCommandInput,
   QueryCommandInput,
   QueryCommandOutput,
@@ -19,7 +20,6 @@ import {
   UpdateCommandOutput
 } from '@aws-sdk/lib-dynamodb'
 import { DynamoDBInterface } from '@symphoniacloud/dynamodb-entity-store'
-import { FakeTable } from './fakeDynamoDBTable.js'
 
 export const METADATA = { $metadata: {} }
 
@@ -132,10 +132,87 @@ export class FakeDynamoDBInterface implements DynamoDBInterface {
     return this.getTable(withTableName.TableName)
   }
 
-  public getTable(tableName: string | undefined) {
+  private getTable(tableName: string | undefined) {
     if (!tableName) throw new Error('Table name is required')
     const table = this.tables[tableName]
     if (!table) throw new Error(`Table ${tableName} not configured`)
     return table
   }
+
+  // Convenience functions
+  public putToTable(tableName: string, item: Record<string, NativeAttributeValue>) {
+    this.getTable(tableName).putItem(item)
+  }
+
+  public getFromTable(tableName: string, key: Record<string, NativeAttributeValue>) {
+    return this.getTable(tableName).get(key)
+  }
+
+  public getAllFromTable(tableName: string) {
+    return this.getTable(tableName).allItems()
+  }
+}
+
+interface TableKey {
+  PK: NativeAttributeValue
+  SK?: NativeAttributeValue
+}
+
+class FakeTable {
+  private readonly pkName: string
+  private readonly skName: string | undefined
+  private readonly items: Map<TableKey, Record<string, NativeAttributeValue>> = new Map<
+    TableKey,
+    Record<string, NativeAttributeValue>
+  >()
+
+  constructor(pkName: string, skName: string | undefined) {
+    this.pkName = pkName
+    this.skName = skName
+  }
+
+  putItem(item: Record<string, NativeAttributeValue> | undefined) {
+    if (!item) return
+    const itemKey = this.keyFromItem(item)
+    // Required because complex key type on items, and otherwise we'd get "duplicate" items
+    this.items.set(this.findMatchingKey(itemKey) ?? itemKey, item)
+  }
+
+  get(key: Record<string, NativeAttributeValue> | undefined) {
+    const matchingKey = this.findMatchingKey(this.keyFromItem(key))
+    return matchingKey ? this.items.get(matchingKey) : undefined
+  }
+
+  deleteItem(key: Record<string, NativeAttributeValue> | undefined) {
+    const matchingKey = this.findMatchingKey(this.keyFromItem(key))
+    if (matchingKey) {
+      this.items.delete(matchingKey)
+    }
+  }
+
+  allItems() {
+    return Array.from(this.items.values())
+  }
+
+  private keyFromItem(item: Record<string, NativeAttributeValue> | undefined): TableKey {
+    if (!item) throw new Error('Item is undefined')
+    const pkValue = item[this.pkName]
+    if (!pkValue) throw new Error(`PK field [${this.pkName}] is not found`)
+    if (this.skName) {
+      const skValue = item[this.skName]
+      if (!skValue) throw new Error(`SK field [${this.skName}] is not found`)
+      return { PK: pkValue, SK: skValue }
+    } else {
+      return { PK: pkValue }
+    }
+  }
+
+  // Required because we have a complex key on items (a Map), and Map only matches object
+  // complex keys if they are the same instance
+  private findMatchingKey(key: TableKey) {
+    for (const tableKey of this.items.keys()) {
+      if (tableKey.PK === key.PK && tableKey.SK === key.SK) return tableKey
+    }
+    return undefined
+  }
 }

packages/dynamodb-entity-store-testutils/src/fakeDynamoDBTable.ts

@@ -1,2 +1 @@
-export { FakeTable } from './fakeDynamoDBTable.js'
 export { FakeDynamoDBInterface, METADATA } from './fakeDynamoDBInterface.js'