test-backend: Raise zerver/views/report.py test coverage to 100%.

tools/test-backend

@@ -97,7 +97,6 @@ not_yet_fully_covered = {
     # Getting views file coverage to 100% is a major project goal
     'zerver/views/auth.py',
     'zerver/views/messages.py',
-    'zerver/views/report.py',
     'zerver/views/home.py',
     'zerver/views/registration.py',
     'zerver/views/events_register.py',

zerver/tests/test_report.py

@@ -143,3 +143,14 @@ class TestReport(ZulipTestCase):
         with self.settings(BROWSER_ERROR_REPORTING=False):
             result = self.client_post("/json/report_error", params)
         self.assert_json_success(result)
+
+        # If js_source_map is present, then the stack trace should be annotated.
+        # DEBUG=False and TEST_SUITE=False are necessary to ensure that
+        # js_source_map actually gets instantiated.
+        with \
+                self.settings(DEBUG=False, TEST_SUITE=False), \
+                mock.patch('zerver.lib.unminify.SourceMap.annotate_stacktrace') as annotate:
+            result = self.client_post("/json/report_error", params)
+        self.assert_json_success(result)
+        # fix_params (see above) adds quotes when JSON encoding.
+        annotate.assert_called_once_with('"trace"')

zerver/views/report.py

@@ -18,11 +18,16 @@ from typing import Optional, Text
 import subprocess
 import os
 
-# Read the source map information for decoding JavaScript backtraces
 js_source_map = None
-if not (settings.DEBUG or settings.TEST_SUITE):
-    js_source_map = SourceMap(os.path.join(
-        settings.DEPLOY_ROOT, 'prod-static/source-map'))
+
+# Read the source map information for decoding JavaScript backtraces.
+def get_js_source_map():
+    # type: () -> Optional[SourceMap]
+    global js_source_map
+    if not js_source_map and not (settings.DEBUG or settings.TEST_SUITE):
+        js_source_map = SourceMap(os.path.join(
+            settings.DEPLOY_ROOT, 'prod-static/source-map'))
+    return js_source_map
 
 @authenticated_json_post_view
 @has_request_variables
@@ -85,6 +90,7 @@ def json_report_error(request, user_profile, message=REQ(), stacktrace=REQ(),
     if not settings.BROWSER_ERROR_REPORTING:
         return json_success()
 
+    js_source_map = get_js_source_map()
     if js_source_map:
         stacktrace = js_source_map.annotate_stacktrace(stacktrace)