I am trying to write some integration tests relative to some methods that needs to extract data from MongoDB. In detail, I am using the Embedded Mongo given by Spring Data project. The embedded mongo is clearly provided by Flapdoodle.
I need to import some json file into the Embedded Mongo. I have looked at the tests provided with flapdoodle, but I am not able to understand how they integrates with the magic given by Spring Data + Spring Boot.
Can anyone post some clarifying snippets?
You can create a junit rule (ExternalResource) which runs before and after each test. Check the MongoEmbeddedRule class to get some idea on the implementation details.
Integration test:
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = RANDOM_PORT)
public abstract class TestRunner {
@Autowired
protected MongoTemplate mongoTemplate;
@Rule
public MongoEmbeddedRule mongoEmbeddedRule = new MongoEmbeddedRule(this);
ExternalResource Rule:
public class MongoEmbeddedRule extends ExternalResource {
private final Object testClassInstance;
private final Map<String, Path> mongoCollectionDataPaths;
private final String fieldName;
private final String getterName;
public MongoEmbeddedRule(final Object testClassInstance) {
this(testClassInstance, "mongoTemplate", "getMongoTemplate");
}
protected MongoEmbeddedRule(final Object testClassInstance, final String fieldName, final String getterName) {
this.fieldName = fieldName;
this.getterName = getterName;
this.testClassInstance = testClassInstance;
this.mongoCollectionDataPaths = mongoExtendedJsonFilesLookup();
}
@Override
protected void before() {
dropCollections();
createAndPopulateCollections();
}
@Override
protected void after() {
}
protected Set<String> getMongoCollectionNames() {
return mongoCollectionDataPaths.keySet();
}
public void dropCollections() {
getMongoCollectionNames().forEach(collectionName -> getMongoTemplate().dropCollection(collectionName));
}
protected void createAndPopulateCollections() {
mongoCollectionDataPaths.forEach((key, value) -> insertDocumentsFromMongoExtendedJsonFile(value, key));
}
protected MongoTemplate getMongoTemplate() {
try {
Object value = ReflectionTestUtils.getField(testClassInstance, fieldName);
if (value instanceof MongoTemplate) {
return (MongoTemplate) value;
}
value = ReflectionTestUtils.invokeGetterMethod(testClassInstance, getterName);
if (value instanceof MongoTemplate) {
return (MongoTemplate) value;
}
} catch (final IllegalArgumentException e) {
// throw exception with dedicated message at the end
}
throw new IllegalArgumentException(
String.format(
"%s expects either field '%s' or method '%s' in order to access the required MongoTemmplate",
this.getClass().getSimpleName(), fieldName, getterName));
}
private Map<String, Path> mongoExtendedJsonFilesLookup() {
Map<String, Path> collections = new HashMap<>();
try {
Files.walk(Paths.get("src","test","resources","mongo"))
.filter(Files::isRegularFile)
.forEach(filePath -> collections.put(
filePath.getFileName().toString().replace(".json", ""),
filePath));
} catch (IOException e) {
e.printStackTrace();
}
return collections;
}
private void insertDocumentsFromMongoExtendedJsonFile(Path path, String collectionName) {
try {
List<Document> documents = new ArrayList<>();
Files.readAllLines(path).forEach(l -> documents.add(Document.parse(l)));
getMongoTemplate().getCollection(collectionName).insertMany(documents);
System.out.println(documents.size() + " documents loaded for " + collectionName + " collection.");
} catch (IOException e) {
e.printStackTrace();
}
}
}
json file (names.json) with MongoDB Extended JSON, where every document is in one line and the collection name is the filename without extension.
{ "_id" : ObjectId("594d324d5b49b78da8ce2f28"), "someId" : NumberLong(1), "name" : "Some Name 1", "lastModified" : ISODate("1970-01-01T00:00:00Z")}
{ "_id" : ObjectId("594d324d5b49b78da8ce2f29"), "someId" : NumberLong(2), "name" : "Some Name 2", "lastModified" : ISODate("1970-01-01T00:00:00Z")}
You can have a look at this following Test class, provided by "flapdoodle". The test shows how to import a JSON file containing the collection dataset: MongoImportExecutableTest.java
You could theoretically also import a whole dump of a database. (using MongoDB restore): MongoRestoreExecutableTest.java
You can create an abstract class and have setup logic to start mongod and mongoimport process.
AbstractMongoDBTest.java
public abstract class AbstractMongoDBTest {
private MongodProcess mongodProcess;
private MongoImportProcess mongoImportProcess;
private MongoTemplate mongoTemplate;
void setup(String dbName, String collection, String jsonFile) throws Exception {
String ip = "localhost";
int port = 12345;
IMongodConfig mongodConfig = new MongodConfigBuilder().version(Version.Main.PRODUCTION)
.net(new Net(ip, port, Network.localhostIsIPv6()))
.build();
MongodStarter starter = MongodStarter.getDefaultInstance();
MongodExecutable mongodExecutable = starter.prepare(mongodConfig);
File dataFile = new File(Thread.currentThread().getContextClassLoader().getResource(jsonFile).getFile());
MongoImportExecutable mongoImportExecutable = mongoImportExecutable(port, dbName,
collection, dataFile.getAbsolutePath()
, true, true, true);
mongodProcess = mongodExecutable.start();
mongoImportProcess = mongoImportExecutable.start();
mongoTemplate = new MongoTemplate(new MongoClient(ip, port), dbName);
}
private MongoImportExecutable mongoImportExecutable(int port, String dbName, String collection, String jsonFile,
Boolean jsonArray, Boolean upsert, Boolean drop) throws
IOException {
IMongoImportConfig mongoImportConfig = new MongoImportConfigBuilder()
.version(Version.Main.PRODUCTION)
.net(new Net(port, Network.localhostIsIPv6()))
.db(dbName)
.collection(collection)
.upsert(upsert)
.dropCollection(drop)
.jsonArray(jsonArray)
.importFile(jsonFile)
.build();
return MongoImportStarter.getDefaultInstance().prepare(mongoImportConfig);
}
@AfterEach
void clean() {
mongoImportProcess.stop();
mongodProcess.stop();
}
public MongoTemplate getMongoTemplate(){
return mongoTemplate;
}
}
YourTestClass.java
public class YourTestClass extends AbstractMongoDBTest{
@BeforeEach
void setup() throws Exception {
super.setup("db", "collection", "jsonfile");
}
@Test
void test() throws Exception {
}
}
