Run configurations slow to open for large groovy test classes

[kernanj]

Tested On:
Eclipse: 2025-06
Plugin: 5.9.0 using 3.0.25 compiler

Eclipse: 2025-12
Plugin: 6.0.0 using 3.0.25 compiler

Steps to reproduce:

• Create groovy test class. I'm using Spock.
• Run the test class
• Right click on test class and go to Run Configurations
• Dialog appears "Searching for test methods in " for a considerable amount of time.

In my case, it took up to 90 seconds to open the run configuration on 2025-06 version.
On 2025-12 version, it took 5-6 times longer.

This was not an issue for the same test class in eclipse 2023-03 using plugin version 4.9.0.

[eric-milles]

I'm guessing it was the parser change. Can you try adding -Dgroovy.antlr4=false to your eclipse.ini and restart?

[kernanj]

Disabling antlr4 didn't seem to make a difference. I've captured call tree between two versions below. I'm using the same test class in both versions.

Eclipse 2023-03 (Plugin v5.0.0)

Eclipse 2025-06

[eric-milles]

Could you try the same with 2026-03 (just released)? There have been a few changes to GroovyCompilationUnitDeclaration recently that may change the profile. It is a lot to ask to compare 5.0.0 to 5.9.0 or 6.0.0 and reason about the changes.

[eric-milles]

I don't see a lot of differences between v5.0.0 and v5.8.0 in GroovyCompilationUnitDeclaration -- unless Spock uses record types a lot. My guess is that the number of compilation unit builds is increased. I did speak with the platform devs some time back about JUnit test scanner parsing classes aggressively. There were some changes made that helped JUnit 4 out, but I think JUnit 5 still had to work out a meta annotation (Testable IIRC).

[eric-milles]

Yes, now I see 35 invocations vs. 1328 invocations. Missed that on first inspection.

[eric-milles]

Here is the check for JUnit 5:
https://github.com/eclipse-jdt/eclipse.jdt.ui/blob/baa72ba00e1eb1610d27b51934f81356b266b4d4/org.eclipse.jdt.junit.core/src/org/eclipse/jdt/internal/junit/launcher/JUnit5TestFinder.java#L250

If you can find a way for it to eliminate types from its scan, that will save a lot of work. I did all I could back in 2022.

• [JUnit] JUnit4TestFinder large project performance eclipse-jdt/eclipse.jdt.ui#302
• Make some performance enhancements to test finders eclipse-jdt/eclipse.jdt.ui#309

[kernanj]

Hi @eric-milles, I've tried out the same test class with the following setup:

eclipse: 2026-03
groovy plugin: Latest SNAPSHOT version - 6.1.0.v202603181442-e2603

With antlr4 enabled, run configuration takes ~14 mins to open
With antlr4 disabled, run configuration take ~3 mins to open

[eric-milles]

Could you try disabling (filtering) all configurations except JUnit here:

I'd like to see your profile report for that. Then if you don't mind, the inverse (filter only JUnit).