Faker Pojo

This library uses datafaker to create Java Objects populated with fake data.

Inspired by the work of aeonflash.

This library has been developed for use in testing environments, though, some may find use for it elsewhere.

Features

• Automatically populate objects by detecting the underlying field data type using reflection
• Support for Records, Lists, Sets, Maps, and Nested objects
• Field level annotation allowing for custom data generation
• Built for Java17

Usage

In the pom.xml, add the following fragment to the dependencies section:

<dependency>
    <groupId>io.github.survival1sm</groupId>
    <artifactId>fakerpojo</artifactId>
    <version>0.0.4.2</version>
</dependency>

For Gradle users, add the following to your build.gradle file.

dependencies {
    implementation 'io.github.survival1sm:fakerpojo:0.0.4.2'
}

Get started

In your Java code:

public class FakerPojo {

	public FakerPojo() {
	}

	private String someStringProperty;
	@FakerField(type = Type.FIRST_NAME)
	private String firstName;
	private Instant lastUpdatedAt;
	private List<Integer> projectIdList;

	//...getters
}

@Test
void someTest() throws Exception {
    MyPojo myPojo = Faker.Builder
      .fromPojo(MyPojo.class)
      .getFirst()
      .build();

    System.out.println(myPojo.toString());

// FakerPojo{someStringProperty='Dolore et ', firstName='Rigoberto', lastUpdatedAt=2019-07-05T02:37:58.910Z, projectIdList=[228099, 443978]}
}

Builder Options

• getFirst()
• toSet()
• toList()
• toMapOnKey(String key)
• usingValueMapList(List<Map<String, Object>> valueMapList)

Builder Modifiers

• withOverrides(Map<String, Object> overrides)
• withRecords()
• withUniqueOnKey()

Note:

Not all builder options/modifiers are available for all builders, some may throw an UnsupportedOperationException exception

Custom Data Generators

You can add your own custom data generators in a few steps:

Add your custom types to the existing types:

public class TestTypes extends Type {

  public static final String EMPLOYEE_NUMBER = "EMPLOYEE_NUMBER";
  public static final String EMPLOYEE_NUMBER_STRING = "EMPLOYEE_NUMBER_STRING";
  public static final String TYPE_NANOID = "TYPE_NANOID";
  public static final String LIST_PROJECT_NANOID = "LIST_PROJECT_NANOID";
}

Provide an implementation of FieldValueGenerator for your new types:

public class TestValueGenerators {

  private static final Faker faker = new Faker();

  public static FieldValueGenerator employeeNumberValueGenerator = (FakerFieldProps fieldProps) -> faker.number().numberBetween(20, 1200000);

  public static FieldValueGenerator employeeNumberStringValueGenerator = (FakerFieldProps fieldProps) -> String.valueOf(faker.number().numberBetween(20, 1200000));

  public static FieldValueGenerator typeNanoIdValueGenerator = (FakerFieldProps fieldProps) -> NanoIdService.getNanoId(NanoPrefix.type);

  public static FieldValueGenerator listProjectNanoIdValueGenerator = (FakerFieldProps fieldProps) -> {
      IntStream range = IntStream.range(0, fieldProps.getRecords());

      return range.mapToObj((int i) -> NanoIdService.getNanoId(NanoPrefix.project)).collect(Collectors.toList());
  };
}

Register your new types:

  @BeforeAll
static void addTestValueGenerator() {
  FakerPojo.addFieldValuesGenerator(TestTypes.EMPLOYEE_NUMBER,TestValueGenerators.employeeNumberValueGenerator);
  FakerPojo.addFieldValuesGenerator(TestTypes.EMPLOYEE_NUMBER_STRING,TestValueGenerators.employeeNumberStringValueGenerator);
  FakerPojo.addFieldValuesGenerator(TestTypes.TYPE_NANOID,TestValueGenerators.typeNanoIdValueGenerator);
  FakerPojo.addFieldValuesGenerator(TestTypes.LIST_PROJECT_NANOID,TestValueGenerators.listProjectNanoIdValueGenerator);
}

Use your custom types

public class CustomValueGeneratorTestDomain {

  public CustomValueGeneratorTestDomain() {
  }

  @FakerField(type = TestTypes.EMPLOYEE_NUMBER)
  private final Integer testEmployeeNumber;
  @FakerField(type = TestTypes.EMPLOYEE_NUMBER_STRING)
  private final String testEmployeeNumberString;
  @FakerField(type = TestTypes.TYPE_NANOID)
  private final String testNanoId;
  @FakerField(type = TestTypes.LIST_PROJECT_NANOID)
  private final List<String> testNanoIdList;

	// .. getters
}

@Test
void build_custom_value_generator_returns_expected_values()throws Exception{
  CustomValueGeneratorTestDomain test = FakerPojo.Builder
      .fromPojo(CustomValueGeneratorTestDomain.class)
      .getFirst()
      .build();

  System.out.println(test.toString());
}

// CustomValueGeneratorTestDomain{testEmployeeNumber=1038479, testEmployeeNumberString='651836', testNanoId='TYP-ltwtfbRFst', testNanoIdList=[PRJ-vNB8cnxlPk, PRJ-5CG0RSpDx4]}

Usage with Locales

@BeforeAll
static void setFakerLocale(){
    FakerPojo.setLocale(new Locale("en","US"));
}

Types

A complete list of default types:

• Full Name
• Last Name
• First Name
• Paragraph
• URL
• Phone Number
• Email
• City
• State
• Integer
• int
• Boolean
• Double
• String
• Date
• Local Date
• Local Datetime
• Offset Datetime
• Float
• Long
• Instant
• Enum
• UUID
• Duration
• Class (POJO)
• List
• Map
• Set

Contributing

Thank you for your interest! PR's welcome!

LICENSE

Licensed under the Apache License, Version 2.0