Mongockito

Java library for Mongodb repository unit testing.

Description

Currently, there is no library that allows you to build an H2-style mongodb in memory.

Starting from the premise in which the database is correctly configured, using the mockito library and based on ArgumentCaptor, we can validate that the fields sent to mongodb are the expected ones.

Prerequisites

• Java: 17
• Spring-boot based: 3.2.2

NOTE: There are a compile error with Java 21, but it's compatible with java 21 projects.

Installation

    <dependency>
        <groupId>io.mongockito</groupId>
        <artifactId>mongockito</artifactId>
        <version>${mongockito.version}</version>
        <scope>test</scope>
    </dependency>

Releases:

• Mongockito release packages

Release	Date	Information
1.0-SNAPSHOT	2-may-24	First release
2.0-SNAPSHOT	13-may-24	refactoring builder methods

Validations

Operation

Operation	Spring Documentation
FIND	find
FIND_ONE	findOne
FIND_BY_ID	findById
FIND_AND_REMOVE	findAndRemoce
UPDATE_FIRST	updateFirst
UPDATE_MULTI	updateMulti
UPSERT	upsert
SAVE	save

ValidationType

Validation	Description
EQUALS	Validates that the value of a field is as expected
NOT_NULL	Validates that the field is not null
NULL	Validates that the field is null
COLLECTION_SIZE	Validates that collection has expected number of elements
JSON	Validates that the json to be inserted in the collection is equal to the input object
JSON_BY_KEY	Validate that a part of json to be inserted in the collection is equal to comparable object

Alternative validations

• There are the following types of validations

Simplified Method	ValidationType
validatesEquals	EQUALS
validatesNotNull	NOT_NULL
validatesNull	NULL
validatesCollectionSize	COLLECTION_SIZE
validatesJson	JSON
validatesJsonByKey	JSON_BY_KEY

NOTE: all this functions can be replaced by one single function with parameters, see VerifyTest class for more examples

    // use this
    .validates(ValidationType.NULL, NULLABLE_FIELD_NAME)
    // instead of him own method
    .validatesNull(NULLABLE_FIELD_NAME)

Other configuration attributes

• addVerificationMode:
  • Allows verifying that certain behavior happened at least once / exact number of times / never. E.g: (MockitoDoc)
• fromCollection:
  • Optional parameter used to indicate the mongo collection name as an attribute instead of being embedded inside the entity bean using the @Document annotation.
• addAdapter:
  • With this operation we can add gson TypeAdapter class (Gson)
• allowSerializeNulls:
  • This parameter will indicate if the data used in the mongo operation aggregates the entity null fields

Examples:

To see a complete example, follow this documentation

• The following example will validate MongoDB save operation of a collection item defined by identifier, and will check that the attached fields have been sent to the DB as intended.

    public static final String ID_FIELD = new ObjectId().toHexString();

    Verify.that()
        .thisOperation( Operation.SAVE )
        .ofClass( EntityExample.class )
        .validatesEquals( "_Id", ID_FIELD )
        .validatesEquals( "boolean_field", true )
        .validatesEquals( "string_field", "name" )
        .validatesNull( "one_field" )
        .validatesNotNull( "another_field" )
        .run( <mongoTemplate> );

• This is an example to validate no field is missing on save operation

    public static final String ID_FIELD = new ObjectId().toHexString();
    public static final LocalDateTime LOCAL_DATE_TIME_NOW = LocalDateTime.now();

    // Item sent on save operation and want to check no field is missing
    final EntityExample entityExample = EntityExample.builder()
        .id( ID_FIELD )
        .month( "02" )
        .locked( Boolean.TRUE )
        .creationUser( "User_a" )
        .creationTimestamp( LOCAL_DATE_TIME_NOW )
        .lastUpdateUser( "User_b" )
        .lastUpdateTimestamp( LOCAL_DATE_TIME_NOW.plusDays( INTEGER_ONE ) )
        .entityExampleMap( createFieldMap() )
        .build();
	
    // Validation
    Verify.that()
        .thisOperation( Operation.SAVE )
        .ofClass( EntityExample.class )
        .validatesJson( EntityExample.class,  entityExample )
        .addVerificationMode(times(INTEGER_ONE))
        .run( <mongoTemplate> );
	

• In this example we validate with specific methods for the save operation

    public static final String ID_FIELD = new ObjectId().toHexString();
    public static final LocalDateTime LOCAL_DATE_TIME_NOW = LocalDateTime.now();

    // Item sent on save operation and want to check no field is missing
    final EntityExample entityExample = EntityExample.builder()
        .id( ID_FIELD )
        .month( "02" )
        .locked( Boolean.TRUE )
        .creationUser( "User_a" )
        .creationTimestamp( LOCAL_DATE_TIME_NOW )
        .lastUpdateUser( "User_b" )
        .lastUpdateTimestamp( LOCAL_DATE_TIME_NOW.plusDays( INTEGER_ONE ) )
        .entityExampleMap( createFieldMap() )
        .build();
	
    // Validation
    Verify.that()
        .thisOperation( Operation.SAVE )
        .ofClass( EntityExample.class )
        .fromCollection( "document_collection_example_name" ) // instead of use @Document in Entity Bean
        .validatesJson(entityExample)
        .validatesJsonByKey(ENTITY_EXAMPLE_MAP, entityExample.getEntityExampleMap())
        .validatesNull(NULLABLE_VALUE_FIELD)
        .validatesNotNull(DEFAULT_KEY_ID)
        .validatesEquals(DEFAULT_KEY_ID, entityExample.getId())
        .validatesCollectionSize(ENTITY_EXAMPLE_LIST, entityExample.getEntityExampleList().size())
        .run( <mongoTemplate> );