Event based testing for android

Question

I'm using robotium for testing and I'm running into a bunch of timing issues that are making it difficult for me to know when an activity (or view) is done loading. As a result the tests I'm writing are not very robust.

I'm looking for a way to instrument my application under test with events that can be pushed to the test framework. If my application under test could "tell" my tests when an expect event occurs, this would be very useful. I've used Event Tracing for Windows for windows\windows phone in the past to great effect.

The poor mans way of doing this that I'm looking at is to have my test application read the logcat in realtime and notify the test when an expected event occurs.

Does anyone have any other ideas?

Answer 1

To solve this I'm relying on the OS logcat. I instrument portions of the code being tested with trace messages and wait for them to occur in the test code. Its perhaps not the most performant way of doing things, but it suits my needs. I first tried to make an asynctask that read from the logcat, but ran into timing issues. I finally implemented something like this:

    logger.info("Click on something");
    EmSingleton.get().setCheckPoint();
    solo.clickOnText(SOMETHING, 1, true); // writes RELOAD_COMPLETE to logcat when done

    logger.info("Validate that the event is done);
    EmSingleton.get().waitForEvent(GrouponLnConstants.TodaysDeal.RELOAD_COMPLETE, 15000);
    // Do other stuff... 

EventManager code (That I wrapped in a singleton called EmSingleton):

public class EventManager {
private ArrayList<String> args = null;
private long startTime;

public EventManager() {
    args = new ArrayList<String>(Arrays.asList("-v", "time", "-d"));
    setCheckPoint();
}

public EventManager(ArrayList<String> _args) {
    this();
    for(String s: args) {
        if (!args.contains(s)) {
            args.add(s);
        }
    }
}

public void setCheckPoint()
{
    Time startTimeOS = new android.text.format.Time();
    startTimeOS.setToNow();
    startTime = startTimeOS.toMillis(true);
}

public LogEvent checkEvent(String filter) throws Exception {
    ArrayList<LogEvent> events = gatherEvents();

    for(LogEvent event: events){
        if(event.checkMsgSubstring(filter)){
            return event;
        }
    }

    return null;
}

public LogEvent waitForEvent(String filter, int timeout) throws Exception
{
    int retries = timeout/1000 == 0 ? 1 : timeout/1000;
    for(int i = 0; i < retries; i++)
    {
        LogEvent event = checkEvent(filter);
        if(event != null){
            return event;
        }
        Thread.sleep(1000);
    }
    return null;
}

public ArrayList<LogEvent> getEvents() {
    return gatherEvents();
}

public void clearEvents() throws Exception{
    ArrayList<String> commandLine = new ArrayList<String>();
    commandLine.add("logcat");
    commandLine.add("-c");

    ProcessBuilder pb = new ProcessBuilder(commandLine.toArray(new String[0]));
    pb.redirectErrorStream(true);
    Process logcatProcess = pb.start();

    logcatProcess.waitFor();
}

protected ArrayList<LogEvent> gatherEvents() {
    ArrayList<LogEvent> events = new ArrayList<LogEvent>();
    final StringBuilder log = new StringBuilder();
    BufferedReader br;
    try {
        ArrayList<String> commandLine = new ArrayList<String>();
        commandLine.add("logcat");
        if (null != args) {
            commandLine.addAll(args);
        }

        ProcessBuilder pb = new ProcessBuilder(commandLine.toArray(new String[0]));
        pb.redirectErrorStream(true);
        Process logcatProcess = pb.start();

        InputStream is = logcatProcess.getInputStream();
        InputStreamReader isr = new InputStreamReader(is);
        br = new BufferedReader(isr);

        String line = null;

        while (true) {
            line = br.readLine();
            if(line == null){
                break;
            }
            // Add events to the events arraylist if they occur after the LogCollector has started to run
            LogEvent event = new LogEvent(line);
            if(event.peekTimeMS() > startTime)
            {
                events.add(event);
            }
        }
    } catch (Exception e) {
        TestLogger.get().error("GrouponTest", String.format("gatherEvents doInBackground failed: %s", e.toString()));
    }

    return events;
}
}

You'll need to set the following permission in your application:

<uses-permission android:name="android.permission.READ_LOGS">

I also created a LogEvent Object to parse events coming from the logcat:

public class LogEvent {
String orignalString = null;
boolean parsed = false;

long timeMs = 0;
String timeString = null;
String verbosity = null;
String tag = null;
int pid = 0;
String msg = null;

// Lazy factory design pattern
// http://en.wikipedia.org/wiki/Lazy_initialization
public LogEvent(String s) {
    orignalString = s;
}

public long getTimeMs() {
    checkInit();
    return timeMs;
}

public long peekTimeMS()
{
    // Time is always formattted as such: MM-DD HH:MM:SS.XXX
    return parseTime(orignalString.substring(0,5), orignalString.substring(6,18));
}

public String getTimeString() {
    checkInit();
    return timeString;
}

public String getVerbosity() {
    checkInit();
    return verbosity;
}

public String getTag() {
    checkInit();
    return tag;
}

 public int getPid() {
    checkInit();
    return pid;
}

public String getMsg() {
    checkInit();
    return msg;
}

/**
 * Checks to see if the event message contains a substring
 * @param check
 * @return
 */
public Boolean checkMsgSubstring(String check)
{
    int index = orignalString.indexOf(check);
    boolean isSubstring = (index >= 0);
    return isSubstring;
}

public String toString()
{
    checkInit();
    return String.format("%s %s/%s(%d): %s", timeString, verbosity, tag, pid, msg);
}

private void checkInit()
{
    if(!parsed)
    {
        parseEvent();
        parsed = true;
    }
}

private void parseEvent()
{
    try{
    String [] splits = orignalString.split("[ ]+");
    // Sometimes the PID is of format ( XX) instead of (XX)
    if(splits[2].indexOf(")") < 0)
    {
        splits[2] += splits[3];
        ArrayList<String> formatted = new ArrayList<String>(Arrays.asList(splits));
        formatted.remove(3);
        splits = formatted.toArray(new String[formatted.size()]);
    }

    // Parse time
    timeMs = parseTime(splits[0], splits[1]);
    timeString = String.format("%s %s", splits[0], splits[1]);
    // Parse tag
    verbosity = parseVerbosity(splits[2]);
    tag = parseTag(splits[2]);
    pid = parsePid(splits[2]);
    // Parse message (may be empty)
    if (splits.length > 3) {
        msg = orignalString.substring(orignalString.indexOf(splits[3]));
    } else {
        msg = "";
    }
    }
    catch (Exception e)
    {
        // TODO: there are some strangely formated events in the system. need to deal with these?
    }
}

/**
 * Time comes in following format: 08-11 20:03:17.182:
 * Parse into milliseconds
 * @param day string of format 08-11
 * @param hours string of format 20:03:17.182:
 * @return
 */
private long parseTime(String day, String hours)
{
    Time timeToSet = new Time();
    Time currentTime = new Time();
    currentTime.setToNow();

    // Parse fields
    String[] daySplits = day.split("-");
    if(daySplits.length < 2)
        return 0;

    String[] hourSplits = hours.split(":");
    if(hourSplits.length < 2)
        return 0;

    String[] secondSplits = hourSplits[2].split("\\.");
    if(secondSplits.length < 2)
        return 0;

    int _year = currentTime.year;
    int _month = Integer.parseInt(daySplits[0])-1;
    int _day = Integer.parseInt(daySplits[1]);
    int _hour = Integer.parseInt(hourSplits[0]);
    int _min = Integer.parseInt(hourSplits[1]);
    int _sec = Integer.parseInt(secondSplits[0]);
    int _mili = Integer.parseInt(secondSplits[1]);

    //set(int second, int minute, int hour, int monthDay, int month, int year)
    timeToSet.set(_sec, _min, _hour, _day, _month, _year);

    // return calculated value
    long parsedTimeInMili = timeToSet.toMillis(true) + (long)_mili;
    return parsedTimeInMili;
}

private String parseVerbosity(String s)
{
    return s.split("/")[0];
}

private String parseTag(String s)
{
    int verbosityLength = parseVerbosity(s).length() +1;
    String tagPart = s.substring(verbosityLength);
    return tagPart.split("\\(")[0];
}

private int parsePid(String s)
{
    try {
        String pidPart = s.split("\\(")[1];
        return Integer.parseInt(pidPart.split("\\)")[0]);
    } catch (Exception e) {
        e.toString();
    }
    return -1;
}
}