Airblader / junit-dataprovider

A TestNG like dataprovider runner for JUnit

junit-dataprovider

Table of Contents

[What is it](#What is it)
[Motivation and distinction](#Motivation and distinction)
Requirements
Download
[Usage example](#Usage example)
[Eclipse template](#Eclipse template)

What is it

A TestNG like dataprovider (see here) runner for JUnit having a simplified syntax compared to all the existing JUnit features.

Motivation and distinction

What is the advantage compared to JUnit Theories?

Test cases for JUnit Theories are built from all data points whose type matches the method's argument – or even the cross product of all matching data points, if the method takes several arguments. The junit-dataprovider, however, ddresses another use case: Its test cases may consist of multiple parameters that belong together, which may contain test input values and/or expected values to assert the result. Furthermore, a test method using JUnit Theories fails or succeeds entirely (for alle data points), on the contrary the junit-dataprovider considers each row of the data provider as standalone test case.

Why can I not use JUnit Theories and data points containing DTOs for test cases?

Of course, this is also a possible way to use JUnit Theories, constructing DTOs for every single data point causes a lot of boiler plate code and inconvenience. This is AFAIK also the case when you use the ParameterSupplier feature of JUnit Theories, where you additionally need a custom Annotation and a class...

But why does JUnit not support data providers?

They do, having another name for it, tough, just see Parameterized. The advantage of this concept is surely that it is completely typesafe. But unfortunatly one has to create a class per data provider or parameterized test, respectively, which is IMHO also overkill. The tests of a single unit (i.e. class) have to be divided into different classes, which need to be maintained (renamed, moved etc.) separately. Furthermore, Parameterized tests (even if there are more than a single test method within one test class) can only be executed altoghter for a test class. A junit dataprovider test, though, can be executed independent on test method level (even if the same data provider is reused for more than one test method).

Is it possible to execute a junit-dataprovider test method for a single test data row?

Unfortunately this is not possible directly expect if the other test data rows are uncommented in the source code. The rerun of a single test data row is working, though, if e.g. in Eclipse you right click the test to be executed and choose run/debug.

Requirements

This JUnit dataprovider requires JUnit in version 4.8.2+ (see junit-dep-4.8.2 / junit-4.8.2).

If you are using a previous version and cannot upgrade, please let us know by opening an issue.

Download

All released (= tagged) versions are available at Maven Central Repository. Following this link you can choose a version. Now either download it manually or see the Dependency Information section how to integrate it with your dependency management tool.

Usage example

import static org.junit.Assert.*;

import org.junit.Test;
import org.junit.runner.RunWith;

import com.tngtech.java.junit.dataprovider.DataProvider;
import com.tngtech.java.junit.dataprovider.DataProviderRunner;
import com.tngtech.java.junit.dataprovider.UseDataProvider;

@RunWith(DataProviderRunner.class)
public class DataProviderTest {

    @DataProvider
    public static Object[][] dataProviderAdd() {
        // @formatter:off
        return new Object[][] {
                { 0, 0, 0 },
                { 1, 1, 2 },
                /* ... */
        };
        // @formatter:on
    }

    @Test
    @UseDataProvider("dataProviderAdd")
    public void testAdd(int a, int b, int expected) {
        // Given:

        // When:
        int result = a + b;

        // Then:
        assertEquals(expected, result);
    }
}

Eclipse template

• Name: dataProvider
• Context: Java type members
• Automatically insert: false
• Description: Insert a junit dataprovider method
• Use code formatter: false (unfortunately, this is a global setting for all templates)
• Pattern:

@${dataProviderType:newType(com.tngtech.java.junit.dataprovider.DataProvider)}
public static Object[][] dataProvider${Name}() {
    // @formatter:off
	return new Object[][] {
		{ ${cursor} },
	};
	// @formatter:on
}