Test_org_eclipse_swt_graphics_Image test fails since I20250406-1800

[iloveeclipse]

See https://download.eclipse.org/eclipse/downloads/drops4/I20250406-1800/testResults.php

Regression from #1999

Typical fail looks like:

test_ConstructorLorg_eclipse_swt_graphics_Device_ImageDataProvider	Error	Missing scheme

java.lang.IllegalArgumentException: Missing scheme
at java.base/java.nio.file.Path.of(Path.java:200)
at org.eclipse.swt.tests.junit.SwtTestUtil.getPath(SwtTestUtil.java:600)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_graphics_Image.lambda$1(Test_org_eclipse_swt_graphics_Image.java:77)
at org.eclipse.swt.internal.DPIUtil.lambda$2(DPIUtil.java:546)
at org.eclipse.swt.internal.DPIUtil.getElementAtZoom(DPIUtil.java:575)
at org.eclipse.swt.internal.DPIUtil.validateAndGetImageDataAtZoom(DPIUtil.java:546)
at org.eclipse.swt.graphics.Image.initFromImageDataProvider(Image.java:788)
at org.eclipse.swt.graphics.Image.<init>(Image.java:653)
at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_graphics_Image.test_ConstructorLorg_eclipse_swt_graphics_Device_ImageDataProvider(Test_org_eclipse_swt_graphics_Image.java:372)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)

[HannesWell]

Will have a look at it this evening, thanks for checking.

[iloveeclipse]

@HannesWell : any chance to work on this? The tests continue to fail...

[HannesWell]

Yes, I'll try to fix it asap. Sorry for the delay.

[HannesWell]

After looking into this and considering the error message (Error Missing scheme) and the stack-trace, that's what I think is happening:
In I-build tests the system-property PLUGIN_PATH is set to the root of the project in
https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/blob/e68f158ea30b4eef72c79011bc099f3505d67109/eclipse.platform.releng.tychoeclipsebuilder/eclipse-junit-tests/src/main/scripts/library.xml#L275
or
https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/blob/e68f158ea30b4eef72c79011bc099f3505d67109/eclipse.platform.releng.tychoeclipsebuilder/eclipse-junit-tests/src/main/scripts/library.xml#L342

And therefore the else branch is taken in SwtTestUtil.getPath():

eclipse.platform.swt/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/SwtTestUtil.java

Lines 587 to 598 in cd7cd6b

	String pluginPath = System.getProperty("PLUGIN_PATH");
	if (pluginPath == null) {
	URL url = SwtTestUtil.class.getResource(fileName);
	assertNotNull(url, "URL == null for file " + fileName);
	try {
	uri = url.toURI();
	} catch (URISyntaxException e) {
	throw new IllegalArgumentException(e);
	}
	} else {
	uri = URI.create(pluginPath + "/data/" + fileName);
	}

But the logic there is not correct anymore: The created URI is syntactically wrong (no schema...) and also points to a location that doesn't exist anymore, as duplicates have been removed from the data-folder in #1999.

My proposed solution is to drop that code path and ignore PLUGIN_PATH. Instead rely on the URL returned by the classloader and resolve it to a file by using FileLocator.toFileURL(), if it's not already a file URL.
In case the test runs locally as a plain JUnit test (without OSGi), the URL is already a file-URL and the FileLocator class, which doesn't work in this case, is not called.
This way the test should work the same in plain JUnit local executions, in verification builds in the CI and in I-build tests. At least that's what I assume and hope.