when:
        sourceFile.text = "class Thing { public void doStuff() {} }"

        then:
        buildTriggeredAndSucceeded()
        vfsLogs.getRetainedFilesSinceLastBuild() >= numberOfFilesInVfs - 1
        vfsLogs.getRetainedFilesInCurrentBuild() >= numberOfFilesInVfs
        executedAndNotSkipped(":compileJava")
        executed(":build")
    }

            def numberMatcher = eventsSinceLastBuild =~ /Received (\d+) file system events since last build while watching \d+ locations/
            return numberMatcher[0][1] as int
        }

        int getRetainedFilesSinceLastBuild() {
            String retainedInformation = spec.result.getOutputLineThatContains("Virtual file system retained information about ")