Gradle test logging

build.gradle

test {
    testLogging {
        events "skipped", "failed", "standardError"

        def outputCache = new LinkedList<String>()

        beforeTest { TestDescriptor td -> outputCache.clear() }    // clear everything right before the test starts

        onOutput { TestDescriptor td, TestOutputEvent toe ->       // when output is coming put it in the cache
            outputCache.add(toe.getMessage())
            while (outputCache.size() > 1000) outputCache.remove() // if we have more than 1000 lines -> drop first
        }

        /** after test -> decide what to print */
        afterTest { TestDescriptor td, TestResult tr ->
            if (tr.resultType == TestResult.ResultType.FAILURE && outputCache.size() > 0) {
                println()
                println(" Output of ${td.className}.${td.name}:")
                outputCache.each { print(" > $it") }
            }
        }

    }
}