abstract class EnvVariableInjection extends BuildInputInjection {
    static EnvVariableInjection environmentVariable(String key, String value) {
        return environmentVariables((key): Objects.requireNonNull(value))
    }

    static EnvVariableInjection environmentVariables(Map<String, String> variables) {
        return new EnvVariableInjection() {
            @Override

        when:
        EnvVariableInjection.environmentVariable("CI", value).setup(this)
        configurationCacheRunLenient "thing"

        then:
        configurationCache.assertStateLoaded()
        problems.assertResultHasProblems(result)
        outputDoesNotContain("apply =")
        outputContains("task = $value")

        when:
        EnvVariableInjection.environmentVariable("CI", newValue).setup(this)

        '''

        when:
        EnvVariableInjection.checkEnvironmentVariableUnset("CI1")
        configurationCacheRun()

        then:
        problems.assertResultHasProblems(result) {
            withInput("Build file 'build.gradle': environment variable 'CI1'")
        }
        outputContains("CI1 = null")

        when:
        EnvVariableInjection.environmentVariable("CI1", "defined").setup(this)