问题
How I can clean database after each it?
In rails I use https://github.com/bmabey/database_cleaner, but I did't find something similar for node.js
node.js (v0.10.26), PostgreSQL (9.3.3), mocha, restify and knex.
回答1:
The easy way I have found to clean the database between test is to
DROP SCHEMA public CASCADE;
CREATE SCHEMA public AUTHORIZATION my_test_user;
Once the public schema belongs to the test user, he is able to drop and re-create the schema when needed. Be aware that drop everything that lies in your database's public schema.
回答2:
You can wrap your test into transaction:
beforeEach(() => {
return connection.query('START TRANSACTION');
});
afterEach(() => {
return connection.query('ROLLBACK');
});
It will be much faster to run tests this way, compared to cleaning, or even worse dropping/recreating schema after each test.
If using it with pooled connections (new Pool()), it will be necessary to limit number of connections to 1: new Pool({min:1, max:1}) - transactions must span single connection.
Postgresql supports nested transactions, so there is no conflicts with other transactions that will be happening during the test it self.
回答3:
There's a good package, check it out: https://github.com/emerleite/node-database-cleaner/
回答4:
I use the database-cleaner package to clean the database before each it directive and the db-migrate package to reset the database before running the tests.
Below the setup.
Add the following devDependencies to your 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",
...
}
Here is the project structure:
.
├── config
│ ├── cleaner-config.js
│ ├── db.js
│ └── ...
├── db
│ ├── database.json
│ └── migrations
│ ├── ...
│ └── sqls
│ └── ...
├── node_modules
├── scripts
│ └── test
├── ...
├── src
│ ├── db.js
│ ├── models
│ └── ...
└── test
├── init.js
└── src
└── ...
The cleaner-config.js:
module.exports = {
postgresql: {
skipTables: ['migrations']
}
};
The config/db.js used to get the database configuration:
// 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')
};
The src/db.js file is responsible for establishing the database connection:
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);
});
};
The test database is hardcoded in the database.json (used also to ):
{
"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
}
I load all my tests at the end of the test/init.js file:
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');
...
Last but not least the scripts/test script used to run the tests:
#!/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
来源：https://stackoverflow.com/questions/22197148/cleaning-database-after-tests-in-node-js