Please ping me (Kyle Y.) on Slack if you run into any issues.

This repo contains a PoC of how multiple plugins in a single repo will be tested and released with CircleCI.

The plugin packages lie in packages. Develop each plugin just as you would for a normal plugin.

See packages/battery for a simple example. Check out flutter/plugins for more real world examples.

For Android, add a test/kotlin directory under android/src, and modify android/build.gradle to add test dependencies like JUnit and Mockito. For example,

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

    testImplementation 'junit:junit:4.13'
    testImplementation 'org.mockito:mockito-core:3.1.0'
    testImplementation 'org.mockito:mockito-inline:3.1.0'  // required for mocking Kotlin classes
    testImplementation 'androidx.test:core:1.2.0'
    testImplementation 'org.robolectric:robolectric:4.3.1'
}

If the mockito-inline dependency doesn't solve the issue with final classes, try creating a file packages/<plugin_name>/android/src/test/resources/mockito-extensions/org.mockito.plugins.MockMaker with a single line:

mock-maker-inline

The tests then can be added under test/kotlin. Typically, put your tests in the same package as the source file (for package level access), and add package statements to the test source files as necessary.

Also, add a line test.java.srcDirs += 'src/test/kotlin' under the android > sourceSets block. This helps Android Studio mark the test directory. Not sure if this is necessary for running tests in CI, though.

These tests can be run with Gradle, by running flutter build apk in example and then running ./gradlew testDebugUnitTest under example/android.

If flutter build apk shows an error about libs.jar, make sure that the version of gradle in example/android/build.gradle shows 3.5.0, not 4.0.0:

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'  // should be 3.5.0, not 4.0.0
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

Currently broken after Flutter 1.20 update. Working on a fix.

(There might be easier ways to do this, but this is what I have been able to figure out so far...)

For iOS, first run flutter build ios --no-codesign in example. Open the example's Xcode workspace, and add your tests by going to the tests tab and creating a new test target. Choose Runner as the test target, and use xxx_pluginTests for the Product Name.

Then you can create new Test classes under that target. Put new Test classes under ios/Tests in the package directory (outside of example). Then you can delete the default test class that Xcode created for you.

Modify ios/xxx.podspec, and add the following to the end of the outermost block (not sure if this step is necessary, but looks like it's done for every plugin with XCTest):

  s.test_spec 'Tests' do |test_spec|
    test_spec.source_files = 'Tests/**/*'
  end

Then your tests can be run with xcodebuild test -workspace Runner.xcworkspace -scheme Runner -destination 'platform=iOS Simulator,name=iPhone 11,OS=13.6' under example/ios, with whatever destination that you like.

If any test dependency is needed, add them in example/ios/Podfile. Also add a line in ios/xxx.podspec in the s.test_spec 'Tests' block: test_spec.dependency 'SomeDependency', '1.0'.

Currently, a new job is run for each of Flutter, Android and iOS, and Flutter has to be downloaded for every job.

The next step would be to parallelize the tests for plugins within each job.