Adds ability to filter the set of tests that are run by a bot

scripts/slave/recipe_modules/filter/example.py

Index: scripts/slave/recipe_modules/filter/example.py
diff --git a/scripts/slave/recipe_modules/filter/example.py b/scripts/slave/recipe_modules/filter/example.py
index 09911b744b6f701e5ce47f8740f213fd0b1b9401..c1388a98c32a06ed6b91e649c030f861420b78d1 100644
--- a/scripts/slave/recipe_modules/filter/example.py
+++ b/scripts/slave/recipe_modules/filter/example.py
@@ -5,6 +5,7 @@
 DEPS = [
   'chromium',
   'filter',
+  'json',
   'path',
   'properties',
   'raw_io',
@@ -16,15 +17,16 @@ def GenSteps(api):
   api.filter.does_patch_require_compile()
   assert (api.filter.result and api.properties['example_result']) or \
       (not api.filter.result and not api.properties['example_result'])
+  assert (not api.properties['example_matching_exes'] or
+          list(api.properties['example_matching_exes']) ==
+          api.filter.matching_exes)
 
 def GenTests(api):
   # Trivial test with no exclusions and nothing matching.
   yield (api.test('basic') +
          api.properties(filter_exclusions=[]) +
          api.properties(example_result=None) +
-         api.override_step_data(
-          'analyze',
-          api.raw_io.stream_output('xx')) +
+         api.properties(example_matching_exes=None) +
          api.override_step_data(
           'git diff to analyze patch',
           api.raw_io.stream_output('yy')))
@@ -33,6 +35,7 @@ def GenTests(api):
   yield (api.test('match_exclusion') +
          api.properties(filter_exclusions=['fo.*']) +
          api.properties(example_result=1) +
+         api.properties(example_matching_exes=None) +
          api.override_step_data(
           'git diff to analyze patch',
           api.raw_io.stream_output('foo.cc')))
@@ -41,9 +44,7 @@ def GenTests(api):
   yield (api.test('doesnt_match_exclusion') +
          api.properties(filter_exclusions=['fo.*']) +
          api.properties(example_result=None) +
-         api.override_step_data(
-          'analyze',
-          api.raw_io.stream_output('xx')) +
+         api.properties(example_matching_exes=None) +
          api.override_step_data(
           'git diff to analyze patch',
           api.raw_io.stream_output('bar.cc')))
@@ -51,6 +52,27 @@ def GenTests(api):
   # Analyze returns matching result.
   yield (api.test('analyzes_returns_true') +
          api.properties(example_result=1) +
+         api.properties(example_matching_exes=None) +
+         api.override_step_data(
+          'analyze',
+          api.json.output({'status': 'Found dependency',
+                                  'targets': []})))
+
+  # Analyze returns matching tests.
+  yield (api.test('analyzes_matches_exes') +
+         api.properties(matching_exes=['foo', 'bar']) +
+         api.properties(example_matching_exes=['foo']) +
+         api.properties(example_result=1) +
+         api.override_step_data(
+          'analyze',
+          api.json.output({'status': 'Found dependency',
+                                  'targets': ['foo']})))
+
+  # Analyze with error condition.
+  yield (api.test('analyzes_error') +
+         api.properties(matching_exes=None) +
+         api.properties(example_matching_exes=None) +
+         api.properties(example_result=1) +
          api.override_step_data(
           'analyze',
-          api.raw_io.stream_output('Found dependency')))
+          api.json.output({'error': 'ERROR'})))