Packaging and referencing images for Sikuli based tests in artifacts

This post describes one approach for packaging/bundling image resources used for Sikuli based automated test cases.

• Bundling images as resources
• Retrieveing/using image resources

That the images used when automating tests using Sikuli needs to versioned should be rather obvious. Naturally the majority of the pictures used in test cases reflects part of the system under test and hance shall be treated and handled as a part of the test code synchronized with what we are actually testing against. This is usually solved by having the test code in the same repository as the code under test, though it might not always be the case.

In a current test setup it was not possible to keep the test code and images together with the code under test so the test code had to be distrubited as an versioned artifact/jar-file.

Test artifact

One if the easier ways for avoiding a lot of test case maintenance is to wrap the interface to the system under test in to an artifact/API/jar-file. This allows for the artifact to be shared between different source control repositories and included in automated tests residing elsewhere (usual scenario when there are multiple trunks and components in a system). For the artifact approach the images to use for the Sikuli based tests needs to be a part of this artifact.

Bundling the images
Out of the box really, well if you are using Maven. Just put the images under resources and they gets bundled correctly in the jar. The location in the repository should be something like this.


src\main
  \- java
      \- org.project.example
  \- resources\images
      \- theImageToLookFor.PNG
      \- otherImage.PNG
      \- ...


That is all there is to it, now distribute the artifact freely, a complete pom for building a complete Sikuli test artifact including images is posted at the end.

Accessing the images in the test code
To be able to reference and use the images in your test there needs to be functionality in the artifact for getting the image resource. So implement a generic getter method that picks up all images correctly for you from inside the jar/artifact during run-time.

class TestArtifact {
	// Image file name must start with the '/' and the image name is
	// case sensitive so be thorough when using.
	private Pattern getPattern(String fileName) throws IOException {
	   BufferedImage image = ImageIO.read(getClass().getResource(fileName));
	   return new Pattern(image);
	}

	// Example method using an image.
	// Screen screen = new Screen();
	public clickOnImage(String imageName) throws Exception {
		Match m = screen.find(getPattern(imageName));
		screen.click(m);
	}
}

Usage inside test cases
Note that when referencing images the path has to start with ‘/’ (fowardslash) to make sure the image is picked up correctly from within the artifact.

class Test {
	private static TestArtifact sikuli = new TestArtifact();
	
	@Test
	public void shallClickImage() throws Exception {
		sikuli.clickOnImage("/images/theImageToLookFor.PNG");
	}
}

Example of artifact pom

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.yourcompany.automation.apis</groupId>
    <artifactId>sikuliwrapper</artifactId>
    <packaging>jar</packaging>
    <name>Sikili wrapper test artifact</name>
    <version>1.0.0-SNAPSHOT</version>
    <inceptionYear>2012</inceptionYear>

    <dependencies>
        <dependency>
            <groupId>org.sikuli</groupId>
            <artifactId>sikuli-script</artifactId>
            <version>0.10.2</version>
            <type>jar</type>
        </dependency>
    </dependencies>

</project>