feat(transaction): afterCommit hook (#10260)

jedwards1211 · sushantdhiman · commit d2428dd580c1 · 2018-12-13T11:58:37.000+05:30
diff --git a/docs/transactions.md b/docs/transactions.md
@@ -219,3 +219,45 @@ sequelize.transaction({
 The `transaction` option goes with most other options, which are usually the first argument of a method.
 For methods that take values, like `.create`, `.update()`, `.updateAttributes()` etc. `transaction` should be passed to the option in the second argument.
 If unsure, refer to the API documentation for the method you are using to be sure of the signature.
+
+## After commit hook
+
+A `transaction` object allows tracking if and when it is committed.
+
+An `afterCommit` hook can be added to both managed and unmanaged transaction objects:
+```js
+sequelize.transaction(t => {
+  t.afterCommit((transaction) => {
+    // Your logic
+  });
+});
+
+sequelize.transaction().then(t => {
+  t.afterCommit((transaction) => {
+    // Your logic
+  });
+
+  return t.commit();
+})
+```
+
+The function passed to `afterCommit` can optionally return a promise that will resolve before the promise chain
+that created the transaction resolves
+
+`afterCommit` hooks are _not_ raised if a transaction is rolled back
+
+`afterCommit` hooks do _not_ modify the return value of the transaction, unlike standard hooks
+
+You can use the `afterCommit` hook in conjunction with model hooks to know when a instance is saved and available outside
+of a transaction
+
+```js
+model.afterSave((instance, options) => {
+  if (options.transaction) {
+    // Save done within a transaction, wait until transaction is committed to
+    // notify listeners the instance has been saved
+    options.transaction.afterCommit(() => /* Notify */)
+    return;
+  }
+  // Save done outside a transaction, safe for callers to fetch the updated model
+  // Notify
diff --git a/lib/transaction.js b/lib/transaction.js
@@ -22,6 +22,7 @@ class Transaction {
   constructor(sequelize, options) {
     this.sequelize = sequelize;
     this.savepoints = [];
+    this._afterCommitHooks = [];
 
     // get dialect specific transaction options
     const transactionOptions = sequelize.dialect.supports.transactionOptions || {};
@@ -71,7 +72,11 @@ class Transaction {
           return this.cleanup();
         }
         return null;
-      });
+      }).tap(
+        () => Utils.Promise.each(
+          this._afterCommitHooks,
+          hook => Promise.resolve(hook.apply(this, [this])))
+      );
   }
 
   /**
@@ -188,6 +193,20 @@ class Transaction {
     }
   }
 
+  /**
+   * A hook that is run after a transaction is committed
+   *
+   * @param {Function} fn   A callback function that is called with the committed transaction
+   * @name afterCommit
+   * @memberof Sequelize.Transaction
+   */
+  afterCommit(fn) {
+    if (!fn || typeof fn !== 'function') {
+      throw new Error('"fn" must be a function');
+    }
+    this._afterCommitHooks.push(fn);
+  }
+
   /**
    * Types can be set per-transaction by passing `options.type` to `sequelize.transaction`.
    * Default to `DEFERRED` but you can override the default type by passing `options.transactionType` in `new Sequelize`.
diff --git a/test/integration/transaction.test.js b/test/integration/transaction.test.js
@@ -5,6 +5,7 @@ const chai = require('chai'),
   Support = require(__dirname + '/support'),
   dialect = Support.getTestDialect(),
   Promise = require(__dirname + '/../../lib/promise'),
+  QueryTypes = require('../../lib/query-types'),
   Transaction = require(__dirname + '/../../lib/transaction'),
   sinon = require('sinon'),
   current = Support.sequelize;
@@ -79,6 +80,31 @@ if (current.dialect.supports.transactions) {
         });
       });
 
+      it('supports running hooks when a transaction is commited', function() {
+        const hook = sinon.spy();
+        let transaction;
+        return expect(this.sequelize.transaction(t => {
+          transaction = t;
+          transaction.afterCommit(hook);
+          return this.sequelize.query('SELECT 1+1', { transaction, type: QueryTypes.SELECT });
+        }).then(() => {
+          expect(hook).to.have.been.calledOnce;
+          expect(hook).to.have.been.calledWith(transaction);
+        })
+        ).to.eventually.be.fulfilled;
+      });
+
+      it('does not run hooks when a transaction is rolled back', function() {
+        const hook = sinon.spy();
+        return expect(this.sequelize.transaction(transaction => {
+          transaction.afterCommit(hook);
+          return Promise.reject(new Error('Rollback'));
+        })
+        ).to.eventually.be.rejected.then(() => {
+          expect(hook).to.not.have.been.called;
+        });
+      });
+
       //Promise rejection test is specifc to postgres
       if (dialect === 'postgres') {
         it('do not rollback if already committed', function() {
@@ -199,6 +225,105 @@ if (current.dialect.supports.transactions) {
       ).to.be.rejectedWith('Transaction cannot be committed because it has been finished with state: commit');
     });
 
+    it('should run hooks if a non-auto callback transaction is committed', function() {
+      const hook = sinon.spy();
+      let transaction;
+      return expect(
+        this.sequelize.transaction().then(t => {
+          transaction = t;
+          transaction.afterCommit(hook);
+          return t.commit().then(() => {
+            expect(hook).to.have.been.calledOnce;
+            expect(hook).to.have.been.calledWith(t);
+          });
+        }).catch(err => {
+          // Cleanup this transaction so other tests don't
+          // fail due to an open transaction
+          if (!transaction.finished) {
+            return transaction.rollback().then(() => {
+              throw err;
+            });
+          }
+          throw err;
+        })
+      ).to.eventually.be.fulfilled;
+    });
+
+    it('should not run hooks if a non-auto callback transaction is rolled back', function() {
+      const hook = sinon.spy();
+      return expect(
+        this.sequelize.transaction().then(t => {
+          t.afterCommit(hook);
+          return t.rollback().then(() => {
+            expect(hook).to.not.have.been.called;
+          });
+        })
+      ).to.eventually.be.fulfilled;
+    });
+
+    it('should throw an error if null is passed to afterCommit', function() {
+      const hook = null;
+      let transaction;
+      return expect(
+        this.sequelize.transaction().then(t => {
+          transaction = t;
+          transaction.afterCommit(hook);
+          return t.commit();
+        }).catch(err => {
+          // Cleanup this transaction so other tests don't
+          // fail due to an open transaction
+          if (!transaction.finished) {
+            return transaction.rollback().then(() => {
+              throw err;
+            });
+          }
+          throw err;
+        })
+      ).to.eventually.be.rejectedWith('"fn" must be a function');
+    });
+
+    it('should throw an error if undefined is passed to afterCommit', function() {
+      const hook = undefined;
+      let transaction;
+      return expect(
+        this.sequelize.transaction().then(t => {
+          transaction = t;
+          transaction.afterCommit(hook);
+          return t.commit();
+        }).catch(err => {
+          // Cleanup this transaction so other tests don't
+          // fail due to an open transaction
+          if (!transaction.finished) {
+            return transaction.rollback().then(() => {
+              throw err;
+            });
+          }
+          throw err;
+        })
+      ).to.eventually.be.rejectedWith('"fn" must be a function');
+    });
+
+    it('should throw an error if an object is passed to afterCommit', function() {
+      const hook = {};
+      let transaction;
+      return expect(
+        this.sequelize.transaction().then(t => {
+          transaction = t;
+          transaction.afterCommit(hook);
+          return t.commit();
+        }).catch(err => {
+          // Cleanup this transaction so other tests don't
+          // fail due to an open transaction
+          if (!transaction.finished) {
+            return transaction.rollback().then(() => {
+              throw err;
+            });
+          }
+          throw err;
+        })
+      ).to.eventually.be.rejectedWith('"fn" must be a function');
+    });
+
     it('does not allow commits after rollback', function() {
       const self = this;
       return expect(self.sequelize.transaction().then(t => {
