baens/test-data-builder

A Java library for building data structures for tests.

Java Test Data Builder

This is a library that helps generate test data for unit tests. The data structures are assumed to be an Immutabled data object. This means that the fields are public final and that each value corresponds to a constructor parameter.

Feature Hightlights

• Populates all fields of class
• Can return an Iterable of data objects
• Can set fields of the class
• Can rotate a number of different settings in the class

Examples

Assume the following data class:

public class Data {
  public final int field1;
  public final String field2;
  
  public Data(int field1, String field2){
    this.field1 = field1;
    this.field2 = field2;
  }
}

You can build a data object:

  Data data = TestDataBuilder.create(Data.class).build();
  // field1 = 1
  // field2 = "2"

You can return an Iterator of objects:

  Iterable<Data> data = TestDataBuilder.create(Data.class).build(3);
  // [
  //    {field1 = 1, field2 = "2"},
  //    {field1 = 1, field2 = "2"},
  //    {field1 = 1, field2 = "2"}
  //  ]

You can set fields inside the object:

Data data = TestDataBuilder
                          .create(Data.class)
                          .set(TestDataBuilder.fieldOf(Data.class).field1,1234)
                          .build();
//field1 = 1234
//field2 = "2"

Fields values can rotate through the iterator:

Iterable<Data> data = Data data = TestDataBuilder
                          .create(Data.class)
                          .set(TestDataBuilder.fieldOf(Data.class).field1,2,4,6)
                          .build(6);
  // [
  //    {field1 = 2, field2 = "2"},
  //    {field1 = 4, field2 = "2"},
  //    {field1 = 6, field2 = "2"},
  //    {field1 = 2, field2 = "2"},
  //    {field1 = 4, field2 = "2"},
  //    {field1 = 6, field2 = "2"}
  //  ]