fix: handle concurrent transaction (#85)

Author: killagu

lib/client.js

@@ -79,12 +79,16 @@ proto.beginTransaction = function* () {
 proto.beginTransactionScope = function* (scope, ctx) {
   ctx = ctx || {};
   if (!ctx._transactionConnection) {
-    ctx._transactionConnection = yield this.beginTransaction();
+    // Create only one conn if concurrent call `beginTransactionScope`
+    ctx._transactionConnection = this.beginTransaction();
+  }
+  const tran = yield ctx._transactionConnection;
+
+  if (!ctx._transactionScopeCount) {
     ctx._transactionScopeCount = 1;
   } else {
     ctx._transactionScopeCount++;
   }
-  const tran = ctx._transactionConnection;
   try {
     const result = yield scope(tran);
     ctx._transactionScopeCount--;

package.json

@@ -24,6 +24,7 @@
     "eslint-config-egg": "^3.2.0",
     "istanbul": "*",
     "mocha": "8",
+    "mz-modules": "^2.1.0",
     "thunk-mocha": "*"
   },
   "homepage": "https://github.com/ali-sdk/ali-rds",

test/client.test.js

@@ -5,6 +5,7 @@ const assert = require('assert');
 const mysql = require('mysql');
 const rds = require('../');
 const config = require('./config');
+const sleep = require('mz-modules/sleep');
 
 describe('client.test.js', function() {
   const prefix = 'prefix-' + process.version + '-';
@@ -414,6 +415,29 @@ describe('client.test.js', function() {
         assert.equal(ctx._transactionScopeCount, 3);
       });
     });
+
+    it('should safe with yield Array', function* () {
+      const ctx = {};
+      yield [
+        this.db.beginTransactionScope(function* (conn) {
+          yield conn.query(
+            'INSERT INTO `ali-sdk-test-user` (name, email, mobile) values(?, ?, "12345678901")',
+            [ prefix + 'should-safe-with-yield-array-1', prefix + 'm@should-safe-with-yield-array-1.com' ]
+          );
+          yield sleep(100);
+        }, ctx),
+        this.db.beginTransactionScope(function* (conn) {
+          yield conn.query(
+            'INSERT INTO `ali-sdk-test-user` (name, email, mobile) values(?, ?, "12345678901")',
+            [ prefix + 'should-safe-with-yield-array-2', prefix + 'm@should-safe-with-yield-array-1.com' ]
+          );
+          yield sleep(200);
+        }, ctx),
+      ];
+      const rows = yield this.db.query(
+        'SELECT * FROM `ali-sdk-test-user` where name like "%should-safe-with-yield-array%"');
+      assert(rows.length === 2);
+    });
   });
 
   describe('beginDoomedTransactionScope(scope)', function() {