Only show images during tests when requested via project property

[thatcomputerguy0101]

Description

Revision of #2164. Instead of only running headless tests during a build, now only the images are disabled. To reenable showing images, the enableTestUi project property needs to be passed to gradle.

./gradlew test -PenableTestUi

Meta

Merge checklist:

• Pull Request title is short, imperative summary of proposed changes
• The description documents the what and why
• This PR has been linted.
• If this PR changes behavior or adds a feature, user documentation is updated
• If this PR touches photon-serde, all messages have been regenerated and hashes have not changed unexpectedly
• If this PR touches configuration, this is backwards compatible with settings back to v2025.3.2
• If this PR touches pipeline settings or anything related to data exchange, the frontend typing is updated
• If this PR addresses a bug, a regression test for it is added

[Gold856]

I'm not sure how I feel about the level of granularity here, or the implementation. It feels like a lot of complexity for little gain. I'd prefer setting and reading environment variables, at the least.

[thatcomputerguy0101]

Fair point to the granularity, since individual tests can also be selected. Why use environment variables over system properties? A dedicated task can be created using system properties if the granularity is removed.

[Gold856]

Environment variables are a little less bespoke in my opinion. You should still be able to have a separate test task that uses a different set of environment variables.

[thatcomputerguy0101]

A GradleBuild task only seems to support setting project or system properties, not environment variables, so I will be using project properties unless you have another solution.

[Gold856]

Did you read the StackOverflow link I sent?

[thatcomputerguy0101]

I meant creating a task that runs the test task after setting an environment variable does not seem to be possible. The post you linked describes how to set an environment variable for the execution of that task, but it does not carry over into other tasks. Are you implying that the contents of the test task should be duplicated?

[Gold856]

Actually, I just realized even environment variables aren't necessary. You can just use systemProperty("java.awt.headless", !project.hasProperty("enableTestUi")) in the test block and that'll be sufficient to control if tests should be run as headless or not, no other modifications needed.

For environment variables, I was envisioning that you just set that for the test task only, similar to how java.awt.headless is set for testHeadless. I'm not sure why you'd want that environment to carry over to other tasks.

[thatcomputerguy0101]

The current implementation of test actually runs all of the headless tests twice, once from test and once from testHeadless. It might be worth only having the test task and parametrizing both the java.awt.headless system property and the exclusion of benchmarks so that headless + benchmarks is the default, advanced debugging can disable headless, and the runner can disable benchmarks. (Although the benchmarks are slow, so maybe they are disabled by default too?)

[Gold856]

Yeah, I’d like to delete testHeadless and just go with the system property controlled by a project property thing I sent. We can just leave the benchmarks as they are in my opinion.

[thatcomputerguy0101]

The build-grade CI task currently runs testHeadless, so the benchmarks will need to be parameterized if the same behavior is kept.

[Gold856]

May as well just run the benchmarks.

[thatcomputerguy0101]

What I pushed now just gives the option for test UI. I found it to be fairly simple to add an option for benchmarks, so I can add that too if the CI run time is bad.

[Gold856]

Beautiful.

[Gold856]

Two more things actually: we should document this in the build instructions and the PR description should be updated. Then I'll merge.

[Gold856]

LGTM