feat(transaction): add support for before and after commit/rollback h…

…ooks

adonis-typings/database.ts

@@ -25,7 +25,11 @@ declare module '@ioc:Adonis/Lucid/Database' {
     DatabaseQueryBuilderContract,
   } from '@ioc:Adonis/Lucid/DatabaseQueryBuilder'
 
-  import { ModelConstructorContract, ModelQueryBuilderContract } from '@ioc:Adonis/Lucid/Model'
+  import {
+    HooksContract,
+    ModelConstructorContract,
+    ModelQueryBuilderContract,
+  } from '@ioc:Adonis/Lucid/Model'
 
   /**
    * A executable query builder will always have these methods on it.
@@ -152,6 +156,8 @@ declare module '@ioc:Adonis/Lucid/Database' {
   export interface TransactionClientContract extends QueryClientContract {
     knexClient: knex.Transaction,
 
+    hooks: HooksContract<'commit' | 'rollback', (client: TransactionClientContract) => void | Promise<void>>
+
     /**
      * Is transaction completed or not
      */

adonis-typings/model.ts

@@ -434,4 +434,16 @@ declare module '@ioc:Adonis/Lucid/Model' {
       options?: ModelAdapterOptions,
     ): ModelQueryBuilderContract<ModelConstructorContract> & ExcutableQueryBuilderContract<ModelContract[]>
   }
+
+  /**
+   * Shape of the hooks contract used by transaction client and models
+   */
+  export interface HooksContract<Events extends string, Handler extends any> {
+    add (lifecycle: 'before' | 'after', event: Events, handler: Handler): this
+    before (event: Events, handler: Handler): this
+    after (event: Events, handler: Handler): this
+    execute (lifecycle: 'before' | 'after', event: Events, payload: any): Promise<void>
+    clear (event: Events): void
+    clearAll (): void
+  }
 }

src/Hooks/index.ts

@@ -0,0 +1,78 @@
+/*
+ * @adonisjs/lucid
+ *
+ * (c) Harminder Virk <virk@adonisjs.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+*/
+
+/// <reference path="../../adonis-typings/index.ts" />
+
+import { HooksContract } from '@ioc:Adonis/Lucid/Model'
+
+/**
+ * A generic class to implement before and after lifecycle hooks
+ */
+export class Hooks<Events extends string, Handler extends any> implements HooksContract<Events, Handler> {
+  private _hooks: {
+    [event: string]: {
+      before: Set<Handler>,
+      after: Set<Handler>,
+    },
+  } = {}
+
+  /**
+   * Add hook for a given event and lifecycle
+   */
+  public add (lifecycle: 'before' | 'after', event: Events, handler: Handler) {
+    this._hooks[event] = this._hooks[event] || { before: new Set(), after: new Set() }
+    this._hooks[event][lifecycle].add(handler)
+    return this
+  }
+
+  /**
+   * Execute hooks for a given event and lifecycle
+   */
+  public async execute (lifecycle: 'before' | 'after', event: Events, payload: any): Promise<void> {
+    if (!this._hooks[event]) {
+      return
+    }
+
+    for (let hook of this._hooks[event][lifecycle]) {
+      await hook(payload)
+    }
+  }
+
+  /**
+   * Register before hook
+   */
+  public before (event: Events, handler: Handler): this {
+    return this.add('before', event, handler)
+  }
+
+  /**
+   * Register after hook
+   */
+  public after (event: Events, handler: Handler): this {
+    return this.add('after', event, handler)
+  }
+
+  /**
+   * Remove hooks for a given event
+   */
+  public clear (event: Events): void {
+    if (!this._hooks[event]) {
+      return
+    }
+
+    delete this._hooks[event]
+  }
+
+  /**
+   * Remove all hooks
+   */
+  public clearAll (): void {
+    this._hooks = {}
+  }
+}

src/TransactionClient/index.ts

@@ -13,6 +13,7 @@ import knex from 'knex'
 import { TransactionClientContract } from '@ioc:Adonis/Lucid/Database'
 import { ProfilerRowContract, ProfilerContract } from '@ioc:Adonis/Core/Profiler'
 
+import { Hooks } from '../Hooks'
 import { ModelQueryBuilder } from '../Orm/QueryBuilder'
 import { RawQueryBuilder } from '../Database/QueryBuilder/Raw'
 import { InsertQueryBuilder } from '../Database/QueryBuilder/Insert'
@@ -39,6 +40,11 @@ export class TransactionClient implements TransactionClientContract {
    */
   public profiler?: ProfilerRowContract | ProfilerContract
 
+  /**
+   * Reference to client hooks
+   */
+  public hooks = new Hooks<'rollback' | 'commit', any>()
+
   constructor (
     public knexClient: knex.Transaction,
     public dialect: string,
@@ -155,13 +161,64 @@ export class TransactionClient implements TransactionClientContract {
    * Commit the transaction
    */
   public async commit () {
-    await this.knexClient.commit()
+    /**
+     * Execute before hooks
+     */
+    await this.hooks.execute('before', 'commit', this)
+
+    /**
+     * Commit and hold the error (if any)
+     */
+    let commitError: any = null
+    try {
+      await this.knexClient.commit()
+    } catch (error) {
+      commitError = error
+    }
+
+    /**
+     * Raise exception when commit fails
+     */
+    if (commitError) {
+      this.hooks.clearAll()
+      throw commitError
+    }
+
+    /**
+     * Execute after hooks
+     */
+    await this.hooks.execute('after', 'commit', this)
+    this.hooks.clearAll()
   }
 
   /**
    * Rollback the transaction
    */
   public async rollback () {
-    await this.knexClient.rollback()
+    /**
+     * Execute before hooks
+     */
+    await this.hooks.execute('before', 'rollback', this)
+
+    let rollbackError: any = null
+    try {
+      await this.knexClient.rollback()
+    } catch (error) {
+      rollbackError = error
+    }
+
+    /**
+     * Raise exception when commit fails
+     */
+    if (rollbackError) {
+      this.hooks.clearAll()
+      throw rollbackError
+    }
+
+    /**
+     * Execute after hooks
+     */
+    await this.hooks.execute('after', 'rollback', this)
+    this.hooks.clearAll()
   }
 }

test/database/transactions.spec.ts

@@ -13,6 +13,7 @@ import test from 'japa'
 
 import { Connection } from '../../src/Connection'
 import { QueryClient } from '../../src/QueryClient'
+import { TransactionClient } from '../../src/TransactionClient'
 import { getConfig, setup, cleanup, resetTables, getLogger } from '../../test-helpers'
 
 test.group('Transaction | query', (group) => {
@@ -98,4 +99,50 @@ test.group('Transaction | query', (group) => {
     assert.lengthOf(results, 1)
     assert.equal(results[0].username, 'virk')
   })
+
+  test('execute before and after commit hooks', async (assert) => {
+    const stack: string[] = []
+    const connection = new Connection('primary', getConfig(), getLogger())
+    connection.connect()
+
+    const db = await new QueryClient('dual', connection).transaction()
+
+    db.hooks.before('commit', (trx) => {
+      stack.push('before')
+      assert.instanceOf(trx, TransactionClient)
+    })
+
+    db.hooks.after('commit', (trx) => {
+      stack.push('after')
+      assert.instanceOf(trx, TransactionClient)
+    })
+
+    await db.insertQuery().table('users').insert({ username: 'virk' })
+    await db.commit()
+    assert.deepEqual(db.hooks['_hooks'], {})
+    assert.deepEqual(stack, ['before', 'after'])
+  })
+
+  test('execute before and after rollback hooks', async (assert) => {
+    const stack: string[] = []
+    const connection = new Connection('primary', getConfig(), getLogger())
+    connection.connect()
+
+    const db = await new QueryClient('dual', connection).transaction()
+
+    db.hooks.before('rollback', (trx) => {
+      stack.push('before')
+      assert.instanceOf(trx, TransactionClient)
+    })
+
+    db.hooks.after('rollback', (trx) => {
+      stack.push('after')
+      assert.instanceOf(trx, TransactionClient)
+    })
+
+    await db.insertQuery().table('users').insert({ username: 'virk' })
+    await db.rollback()
+    assert.deepEqual(db.hooks['_hooks'], {})
+    assert.deepEqual(stack, ['before', 'after'])
+  })
 })