tests: Enforce 100% URL coverage.

We now instrument URL coverage whenever you run the back end tests,
and if you run the full suite and fail to test all endpoints, we
exit with a non-zero exit code and report failures to you.

If you are running just a subset of the test suite, you'll still
be able to see var/url_coverage.txt, which has some useful info.

With some tweaks to the output from tabbott.

Fixes #1441.

tools/test-backend

@@ -50,9 +50,6 @@ if __name__ == "__main__":
     parser.add_option('--coverage', dest='coverage',
                       action="store_true",
                       default=False, help='Compute test coverage.')
-    parser.add_option('--url-coverage', dest='url_coverage',
-                      action="store_true",
-                      default=False, help='Write url coverage data.')
     parser.add_option('--no-verbose-coverage', dest='verbose_coverage',
                       action="store_false",
                       default=True, help='Disable verbose print of coverage report.')
@@ -127,6 +124,8 @@ if __name__ == "__main__":
     for suite in args:
         args[args.index(suite)] = suite.replace("/", ".")
 
+    full_suite = len(args) == 0
+
     if len(args) == 0:
         suites = ["zerver.tests",
                   "analytics.tests"]
@@ -150,11 +149,11 @@ if __name__ == "__main__":
         import cProfile
         prof = cProfile.Profile()
         prof.enable()
-    if options.url_coverage:
-        # This is kind of hacky, but it's the most reliable way
-        # to make sure instrumentation decorators know the
-        # setting when they run.
-        os.environ['TEST_INSTRUMENT_URL_COVERAGE'] = 'TRUE'
+
+    # This is kind of hacky, but it's the most reliable way
+    # to make sure instrumentation decorators know the
+    # setting when they run.
+    os.environ['TEST_INSTRUMENT_URL_COVERAGE'] = 'TRUE'
 
     # setup() needs to be called after coverage is started to get proper coverage reports of model
     # files, since part of setup is importing the models for all applications in INSTALLED_APPS.
@@ -169,7 +168,8 @@ if __name__ == "__main__":
 
     TestRunner = get_runner(settings)
     test_runner = TestRunner()
-    failures = test_runner.run_tests(suites, fatal_errors=options.fatal_errors)
+    failures = test_runner.run_tests(suites, fatal_errors=options.fatal_errors,
+        full_suite=full_suite)
 
     templates_not_rendered = test_runner.get_shallow_tested_templates()
     if templates_not_rendered:

zerver/lib/test_helpers.py

@@ -47,6 +47,7 @@ import base64
 import mock
 import os
 import re
+import sys
 import time
 import ujson
 import unittest
@@ -249,8 +250,8 @@ def instrument_url(f):
             return result
         return wrapper
 
-def write_instrumentation_reports():
-    # type: () -> None
+def write_instrumentation_reports(full_suite):
+    # type: (bool) -> None
     if INSTRUMENTING:
         calls = INSTRUMENTED_CALLS
         var_dir = 'var' # TODO make sure path is robust here
@@ -270,8 +271,9 @@ def write_instrumentation_reports():
                         ''')
                     print(call)
 
-        print('URL coverage report is in %s' % (fn,))
-        print('Try running: ./tools/analyze-url-coverage')
+        if full_suite:
+            print('URL coverage report is in %s' % (fn,))
+            print('Try running: ./tools/analyze-url-coverage')
 
         # Find our untested urls.
         from zproject.urls import urlpatterns
@@ -286,12 +288,12 @@ def write_instrumentation_reports():
             else:
                 untested_patterns.append(pattern.regex.pattern)
 
-        fn = os.path.join(var_dir, 'untested_url_report.txt')
-        with open(fn, 'w') as f:
-            f.write('untested urls\n')
+
+        if full_suite and len(untested_patterns):
+            print("\nERROR: Some URLs are untested!  Here's the list of untested URLs:")
             for untested_pattern in sorted(untested_patterns):
-                f.write('  %s\n' % (untested_pattern,))
-        print('Untested-url report is in %s' % (fn,))
+                print("   %s" % (untested_pattern,))
+            sys.exit(1)
 
 def get_all_templates():
     # type: () -> List[str]

zerver/lib/test_runner.py

@@ -186,8 +186,9 @@ class Runner(DiscoverRunner):
                     return failed
         return failed
 
-    def run_tests(self, test_labels, extra_tests=None, **kwargs):
-        # type: (List[str], Optional[List[TestCase]], **Any) -> bool
+    def run_tests(self, test_labels, extra_tests=None,
+            full_suite=False, **kwargs):
+        # type: (List[str], Optional[List[TestCase]], bool, **Any) -> bool
         self.setup_test_environment()
         try:
             suite = self.build_suite(test_labels, extra_tests)
@@ -208,5 +209,5 @@ class Runner(DiscoverRunner):
         failed = self.run_suite(suite, fatal_errors=kwargs.get('fatal_errors'))
         self.teardown_test_environment()
         if not failed:
-            write_instrumentation_reports()
+            write_instrumentation_reports(full_suite=full_suite)
         return failed