Bug 1036374 - Adding a binary search algorithm for bisection of failing tests. r=jmaher

testing/mochitest/bisection.py

@@ -86,7 +86,7 @@ class Bisect(object):
             tests = self.get_tests_for_bisection(options, tests)
             status = self.setup(tests)
 
-        return self.next_chunk_reverse(options, status)
+        return self.next_chunk_binary(options, status)
 
     def post_test(self, options, expectedError, result):
         "This method is used to call other methods to summarize results and check whether a sanity check is done or not."
@@ -115,13 +115,11 @@ class Bisect(object):
         "This method is used to bisect the tests in a reverse search fashion."
 
         # Base Cases.
-        if self.contents['loop'] == 0:
-            self.contents['loop'] += 1
+        if self.contents['loop'] <= 1:
             self.contents['testsToRun'] = self.contents['tests']
-            return self.contents['testsToRun']
-        if self.contents['loop'] == 1:
+            if self.contents['loop'] == 1:
+                self.contents['testsToRun'] = [self.contents['tests'][-1]]
             self.contents['loop'] += 1
-            self.contents['testsToRun'] = [self.contents['tests'][-1]]
             return self.contents['testsToRun']
 
         if 'result' in self.contents:
@@ -150,6 +148,42 @@ class Bisect(object):
 
         return self.contents['testsToRun']
 
+    def next_chunk_binary(self, options, status):
+        "This method is used to bisect the tests in a binary search fashion."
+
+        # Base cases.
+        if self.contents['loop'] <= 1:
+            self.contents['testsToRun'] = self.contents['tests']
+            if self.contents['loop'] == 1:
+                self.contents['testsToRun'] = [self.contents['tests'][-1]]
+            self.contents['loop'] += 1
+            return self.contents['testsToRun']
+
+        # Initialize the contents dict.
+        if status:
+            totalTests = len(self.contents['tests'])
+            self.contents['start'] = 0
+            self.contents['end'] = totalTests - 2
+
+        mid = (self.contents['start'] + self.contents['end']) / 2
+        if 'result' in self.contents:
+            if self.contents['result'] == "PASS":
+                self.contents['end'] = mid
+
+            elif self.contents['result'] == "FAIL":
+                self.contents['start'] = mid + 1
+
+        mid = (self.contents['start'] + self.contents['end']) / 2
+        start = mid + 1
+        end = self.contents['end'] + 1
+        self.contents['testsToRun'] = self.contents['tests'][start:end]
+        if not self.contents['testsToRun']:
+            self.contents['testsToRun'].append(self.contents['tests'][mid])
+        self.contents['testsToRun'].append(self.contents['tests'][-1])
+        self.contents['loop'] += 1
+
+        return self.contents['testsToRun']
+
     def summarize_chunk(self, options):
         "This method is used summarize the results after the list of tests is run."
         if options.bisectChunk == "default":

testing/mochitest/runtests.py

@@ -1402,7 +1402,7 @@ class Mochitest(MochitestUtilsMixin):
       if options.bisectChunk:
         testsToRun = bisect.pre_test(options, testsToRun, status)
 
-      self.doTests(options, onLaunch, testsToRun)
+      result = self.doTests(options, onLaunch, testsToRun)
       if options.bisectChunk:
         status = bisect.post_test(options, self.expectedError, self.result)
       else:
@@ -1415,9 +1415,8 @@ class Mochitest(MochitestUtilsMixin):
     # Also we need to make sure that we do not print the summary in between running tests via --run-by-dir.
     if options.bisectChunk and options.bisectChunk in self.result:
       bisect.print_summary()
-      return -1
 
-    return 0
+    return result
 
   def runTests(self, options, onLaunch=None):
     """ Prepare, configure, run tests and cleanup """
@@ -1425,8 +1424,7 @@ class Mochitest(MochitestUtilsMixin):
     self.setTestRoot(options)
 
     if not options.runByDir:
-      self.runMochitests(options, onLaunch)
-      return 0
+      return self.runMochitests(options, onLaunch)
 
     # code for --run-by-dir
     dirs = self.getDirectories(options)
@@ -1451,9 +1449,7 @@ class Mochitest(MochitestUtilsMixin):
       # If we are using --run-by-dir, we should not use the profile path (if) provided
       # by the user, since we need to create a new directory for each run. We would face problems
       # if we use the directory provided by the user.
-      runResult = self.runMochitests(options, onLaunch)
-      if runResult == -1:
-        return 0
+      result = self.runMochitests(options, onLaunch)
 
     # printing total number of tests
     if options.browserChrome:
@@ -1470,6 +1466,8 @@ class Mochitest(MochitestUtilsMixin):
       print "3 INFO Todo:    %s" % self.counttodo
       print "4 INFO SimpleTest FINISHED"
 
+    return result
+
   def doTests(self, options, onLaunch=None, testsToFilter = None):
     # A call to initializeLooping method is required in case of --run-by-dir or --bisect-chunk
     # since we need to initialize variables for each loop.