Replace old GIFs with symbols

[strangelookingnerd]

Following a brief discussion with @MarkEWaite (jenkinsci/groovy-postbuild-plugin#81 (comment)) I propose to get rid of the *.gif images.

In order to not break current pipelines an on-the-fly replacement should be implemented. See the following table for my proposal:

name	old	new	origin
completed.gif			core status-blue
db_in.gif			ionicons cloud-upload-outline
db_out.gif			ionicons cloud-download-outline
delete.gif			core trash
error.gif			core status-red
folder.gif			core folder
green.gif			emoji green_square
info.gif			core information-circle
red.gif			emoji red_square
save.gif			ionicon save-outline
success.gif			core status-blue
text.gif			core document-text
warning.gif			core status-yellow
yellow.gif			emoji yellow_square

Some of the icons do not have proper replacements from the core (https://github.com/jenkinsci/jenkins/tree/master/war/src/main/resources/images/symbols) or the ionicons-api-plugin. That's why I added emoji-symbols-api as a dependency to find the missing pieces.

Any feedback is highly welcome!

Testing done

Added tests to cover the replacement

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[MarkEWaite]

I've tested each of the replacements in my Jenkins 2.479.1 controller and they look much better. I've tested several of the gif images from the webapps directory and confirmed that they look good in the build history and continue to be visibly pixelated int he job summary page.

Pipeline that I used to test was:

pipeline {
    agent {
        label 'alpine'
    }
    stages {
        stage('Badge') {
            steps {
                addBadge icon: 'folder-open.gif', text: 'This is a folder open 16x16 icon'
                script {
                    manager.createSummary('folder-open.gif').appendText('This is a folder open')
                }
            }
        }
    }
}

[basil]

org.junit.ComparisonFailure: expected:<[/plugin/badge/images/info.gif]> but was:<[symbol-information-circle]>
	at org.junit.Assert.assertEquals(Assert.java:117)
	at org.junit.Assert.assertEquals(Assert.java:146)
	at org.jvnet.hudson.plugins.groovypostbuild.GroovyPostbuildRecorderTest.testBadgeMigration(GroovyPostbuildRecorderTest.java:481)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.jvnet.hudson.test.JenkinsRule$1.evaluate(JenkinsRule.java:706)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
	at java.base/java.lang.Thread.run(Thread.java:1583)

[strangelookingnerd]

@basil That must have slipped my mind - sorry for the fuzz.