如何在每次之后清理数据库？
在 rails 中，我使用 https://github.com/bmabey/database_cleaner，但我没有找到类似的东西.js
node.js (v0.10.26)， PostgreSQL (9.3.3)， mocha， restify 和 knex.
您可以将测试包装到事务中：
beforeEach(() => {
return connection.query('START TRANSACTION');
});
afterEach(() => {
return connection.query('ROLLBACK');
});
与清理相比，以这种方式运行测试会快得多，甚至更糟的是，在每次测试后删除/重新创建架构。
如果将其与池连接一起使用(new Pool())，则需要将连接数限制为 1：new Pool({min:1, max:1})- 事务必须跨越单个连接。
但是，如果正在测试的代码也使用事务，这将不起作用。可以使用保存点执行嵌套事务，但可能会变得更加复杂。
有一个很好的软件包，看看它：https://github.com/emerleite/node-database-cleaner/
我使用database-cleaner包在每个it指令之前清理数据库，并使用 db-migrate 包在运行测试之前重置数据库。
在设置下方。
将以下devDependencies添加到您的package.json：
"devDependencies": {
"chai": "^3.5.0",
"database-cleaner": "^1.1.0",
"mocha": "^3.0.2",
"db-migrate": "^0.10.0-beta.15",
"db-migrate-pg": "^0.1.10",
...
}
以下是项目结构：
.
├── config
│ ├── cleaner-config.js
│ ├── db.js
│ └── ...
├── db
│ ├── database.json
│ └── migrations
│ ├── ...
│ └── sqls
│ └── ...
├── node_modules
├── scripts
│ └── test
├── ...
├── src
│ ├── db.js
│ ├── models
│ └── ...
└── test
├── init.js
└── src
└── ...
cleaner-config.js：
module.exports = {
postgresql: {
skipTables: ['migrations']
}
};
用于获取数据库配置的config/db.js：
// Prepare default DB config
const defaultOptions = function(environment = 'development') {
const host = 'db';
const port = 5432;
const user = process.env.POSTGRES_USER;
const password = process.env.POSTGRES_PASSWORD;
var conf = {
host: host,
port: port,
user: user,
password: password,
database: process.env.POSTGRES_DB,
max: 10, // max number of clients in the pool
idleTimeoutMillis: 30000 // Keeps idle connections open for a 30 seconds
};
// Change the used database in test environment
if (environment === 'test') {
conf.database = require('../db/database.json').test.database;
}
return conf;
};
// Return database configuration for all environments
module.exports = {
development: defaultOptions(),
test: defaultOptions('test')
};
src/db.js文件负责建立数据库连接：
const PgPool = require('pg-pool');
// create a config to configure both pooling behavior and client options
const CONFIG = require('../config/db')[process.env.NODE_ENV || 'development'];
// Initializes connection pool
const pool = new PgPool(CONFIG);
module.exports = function(callback) {
pool.on('error', function(error, client) {
// if an error is encountered by a client while it sits idle in the pool
// the pool itself will emit an error event with both the error and
// the client which emitted the original error
// this is a rare occurrence but can happen if there is a network partition
// between your application and the database, the database restarts, etc.
// and so you might want to handle it and at least log it out
console.error('idle client error', error.message, error.stack);
});
// to run a query we can acquire a client from the pool,
// run a query on the client, and then return the client to the pool
pool.connect(function(error, client, done) {
if (error)
return console.error('error fetching client from pool', error);
callback(client, done);
});
};
test数据库在database.json中硬编码(也用于)：
{
"test": {
"driver": "pg",
"user": {
"ENV": "POSTGRES_USER"
},
"password": {
"ENV": "POSTGRES_PASSWORD"
},
"host": "db",
"database": "<prefix>_test"
},
"development": {
"driver": "pg",
"user": {
"ENV": "POSTGRES_USER"
},
"password": {
"ENV": "POSTGRES_PASSWORD"
},
"host": "db",
"database": {
"ENV": "POSTGRES_DB"
}
},
"sql-file": true
}
我在test/init.js文件的末尾加载所有测试：
DB = {
client: null,
closeConnection: null
}
beforeEach(function(done) {
require('../src/db')(function(client, dbDone) {
DB.client = client;
DB.closeConnection = dbDone;
var DatabaseCleaner = require('database-cleaner');
var databaseCleaner = new DatabaseCleaner('postgresql');
databaseCleaner.clean(client, done);
});
});
// TODO: close connection only once - at the end of testing
afterEach(function(done) {
DB.client = null;
DB.closeConnection();
done();
});
require('./src/<some library>.test');
...
最后但并非最不重要的是用于运行测试的scripts/test脚本：
#!/bin/bash
script_directory="$( cd "$( dirname "$0" )" && pwd )"
project_directory=$script_directory/..
# Stop execution and exit on any error
set -e
cd $project_directory
db_name='<prefix>_test'
# Drop the DB
# Use the development environment because of this issue: https://github.com/db-migrate/node-db-migrate/issues/393
./node_modules/.bin/db-migrate --env development --migrations-dir db/migrations --config db/database.json db:drop $db_name
# Create the DB
# Use the development environment because of this issue: https://github.com/db-migrate/node-db-migrate/issues/393
./node_modules/.bin/db-migrate --env development --migrations-dir db/migrations --config db/database.json db:create $db_name
./node_modules/.bin/db-migrate --env test --migrations-dir db/migrations --config db/database.json up
NODE_ENV=test ./node_modules/.bin/mocha test/init.js
我发现在测试之间清理数据库的简单方法是
DROP SCHEMA public CASCADE;
CREATE SCHEMA public AUTHORIZATION my_test_user;
一旦公共架构属于测试用户，他就可以在需要时删除并重新创建架构。请注意，删除数据库公共架构中的所有内容。