Running Java GUI tests on GitHub using xvfb - user-interface

Question

I've got some basic automated GUI tests for my Java desktop application that work when running on my Windows desktop. On GitHub they fail with
java.awt.AWTError at X11GraphicsEnvironment.java:-2
I started from the default Java CI with Gradle workflow, and have added some steps attempting to set up xvfb so it has a display to work with, but it's still failing. Is there a way I can modify the workflow so that X11 is available for the tests?
name: Java CI with Gradle
on:
push:
branches: [ main ]
pull_request:
branches: [ main ]
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout#v2
- name: Set up JDK 11
uses: actions/setup-java#v2
with:
java-version: '11'
distribution: 'adopt'
- name: Set up virtual X11
run: sudo apt-get install xvfb
- name: Start virtual frame buffer
run: Xvfb :19 -screen 0 1024x768x16 &
- name: set display
run: export DISPLAY=:19
- name: Grant execute permission for gradlew
run: chmod +x gradlew
- name: Build with Gradle
run: ./gradlew build

Answer 1

I ended up splitting the GUI tests off using JUnit #Tags, and then adding separate gradle tasks:
task nonGuiTest(type: Test) {
useJUnitPlatform {
excludeTags 'gui'
}
}
task guiTest(type: Test) {
useJUnitPlatform {
includeTags 'gui'
}
}
then in the workflow
I run build -x test initially
then run the non-GUI tests
then use the GabrielBB/xvfb-action#v1 action to set up xvfb
then run the GUI tests
name: Java CI with Gradle
on:
push:
branches: [ main ]
pull_request:
branches: [ main ]
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout#v2
- name: Set up JDK 11
uses: actions/setup-java#v2
with:
java-version: '11'
distribution: 'adopt'
- name: Grant execute permission for gradlew
run: chmod +x gradlew
- name: Build with Gradle
run: ./gradlew build -x test
- name: headless tests
run: ./gradlew nonGuiTest
- name: GUI tests
uses: GabrielBB/xvfb-action#v1
with:
run: ./gradlew guiTest