Speed up a few tests and re-enable JS on DirectoryBrowserSupportTest

[timja]

Plugin manager tests sped up by loading plugin without dependencies, a bunch of time was spent waiting for plugin installation / JS to execute in update center.

DirectoryBrowserSupportTest now runs fine with the new HtmlUnit API update in the test harness

See jenkinsci/jenkins-test-harness#985

Testing done

Proposed changelog entries

• human-readable text

Proposed changelog category

/label skip-changelog

Proposed upgrade guidelines

N/A

Submitter checklist

• The Jira issue, if it exists, is well-described.
• The changelog entries and upgrade guidelines are appropriate for the audience affected by the change (users or developers, depending on the change) and are in the imperative mood (see examples). Fill in the Proposed upgrade guidelines section only if there are breaking changes or changes that may require extra steps from users during upgrade.
• There is automated testing or an explanation as to why this change has no tests.
• New public classes, fields, and methods are annotated with @Restricted or have @since TODO Javadocs, as appropriate.
• New deprecations are annotated with @Deprecated(since = "TODO") or @Deprecated(forRemoval = true, since = "TODO"), if applicable.
• New or substantially changed JavaScript is not defined inline and does not call eval to ease future introduction of Content Security Policy (CSP) directives (see documentation).
• For dependency updates, there are links to external changelogs and, if possible, full differentials.
• For new APIs and extension points, there is a link to at least one consumer.

Desired reviewers

@mention

Before the changes are marked as ready-for-merge:

Maintainer checklist

• There are at least two (2) approvals for the pull request and no outstanding requests for change.
• Conversations in the pull request are over, or it is explicit that a reviewer is not blocking the change.
• Changelog entries in the pull request title and/or Proposed changelog entries are accurate, human-readable, and in the imperative mood.
• Proper changelog labels are set so that the changelog can be generated automatically.
• If the change needs additional upgrade steps from users, the upgrade-guide-needed label is set and there is a Proposed upgrade guidelines section in the pull request title (see example).
• If it would make sense to backport the change to LTS, a Jira issue must exist, be a Bug or Improvement, and be labeled as lts-candidate to be considered (see query).

[github-actions]

Please take a moment and address the merge conflicts of your pull request. Thanks!

[timja]

This PR improves test time on my machine:

master:

02:46

Just test harness change:

44.669s

Test change to require less dependency loading:

39.233

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Non scientific testing, haven't run multiple builds and averaged.

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I tried a couple of weeks ago to run many builds and see improvements but was too hard with tests falling over everywhere for other reasons.

A couple of sample builds:

• 8hr 56 - This PR - https://ci.jenkins.io/job/Core/job/jenkins/job/PR-10764/14/testReport/
• 10hr - Another PR - https://ci.jenkins.io/job/Core/job/jenkins/job/PR-11001/2/testReport/

[MarkEWaite]

Thanks!

[jglick]

Do not check in binaries. If you need a random plugin binary, use https://javadoc.jenkins.io/component/jenkins-test-harness/org/jvnet/hudson/test/RealJenkinsRule.html#createSyntheticPlugin(org.jvnet.hudson.test.RealJenkinsRule.SyntheticPlugin)

[jglick]

Is there a reason you closed this @timja?

[timja]

Didn't have the time to address, the more important change was the htmlunit change to not wait forever for JS that is constantly running. These make a bit of difference to an individual test but not huge..