Integration test for Lo-Fi directives in the Chrome-Proxy response header

tools/chrome_proxy/integration_tests/chrome_proxy_metrics.py

Index: tools/chrome_proxy/integration_tests/chrome_proxy_metrics.py
diff --git a/tools/chrome_proxy/integration_tests/chrome_proxy_metrics.py b/tools/chrome_proxy/integration_tests/chrome_proxy_metrics.py
index 68ba33fa311af9bf05d99f082f3cadc31ed68379..a1b79700fff4a632c13031442d1ad1b0f39f62bc 100644
--- a/tools/chrome_proxy/integration_tests/chrome_proxy_metrics.py
+++ b/tools/chrome_proxy/integration_tests/chrome_proxy_metrics.py
@@ -78,15 +78,19 @@ class ChromeProxyResponse(network_metrics.HTTPResponse):
         return kvp[1].strip()
     return None
 
-  def HasChromeProxyLoFi(self):
+  def HasChromeProxyLoFiRequest(self):
     if 'Chrome-Proxy' not in self.response.request_headers:
       return False
     chrome_proxy_request_header = self.response.request_headers['Chrome-Proxy']
     values = [v.strip() for v in chrome_proxy_request_header.split(',')]
-    for value in values:
-      if len(value) == 5 and value == 'q=low':
-        return True
-    return False
+    return any(v == "q=low" for v in values)
+
+  def HasChromeProxyLoFiResponse(self):
+    chrome_proxy_response_header = self.response.GetHeader('Chrome-Proxy')
+    if not chrome_proxy_response_header:
+      return False
+    values = [v.strip() for v in chrome_proxy_response_header.split(',')]
+    return any(v == "q=low" for v in values)
 
 class ChromeProxyMetric(network_metrics.NetworkMetric):
   """A Chrome proxy timeline metric."""
@@ -301,27 +305,40 @@ class ChromeProxyMetric(network_metrics.NetworkMetric):
         results.current_page, 'bypass', 'count', bypass_count))
 
   def AddResultsForLoFi(self, tab, results):
-    lo_fi_count = 0
+    lo_fi_request_count = 0
+    lo_fi_response_count = 0
 
     for resp in self.IterResponses(tab):
-      if resp.HasChromeProxyLoFi():
-        lo_fi_count += 1
+      if resp.HasChromeProxyLoFiRequest():
+        lo_fi_request_count += 1
       else:
         raise ChromeProxyMetricException, (
             '%s: LoFi not in request header.' % (resp.response.url))
 
+      if resp.HasChromeProxyLoFiResponse():
+        lo_fi_response_count += 1
+      else:
+        raise ChromeProxyMetricException, (
+            '%s: LoFi not in response header.' % (resp.response.url))
+
       if resp.content_length > 100:
         raise ChromeProxyMetricException, (
             'Image %s is %d bytes. Expecting less than 100 bytes.' %
             (resp.response.url, resp.content_length))
 
-    if lo_fi_count == 0:
+    if lo_fi_request_count == 0:
+      raise ChromeProxyMetricException, (
+          'Expected at least one LoFi request, but zero such requests were '
+          'received.')

[sclittle, 2015/05/14 22:03:25]

nit: wording seems a bit strange, "requests were received". Maybe "requests were
sent" or something instead?

[megjablon, 2015/05/15 00:38:10]

Ah ya forgot to fix that part. Done.

+    if lo_fi_response_count == 0:
       raise ChromeProxyMetricException, (
           'Expected at least one LoFi response, but zero such responses were '
           'received.')
 
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'lo_fi', 'count', lo_fi_count))
+        results.current_page, 'lo_fi_request', 'count', lo_fi_request_count))
+    results.AddValue(scalar.ScalarValue(
+        results.current_page, 'lo_fi_response', 'count', lo_fi_response_count))
     super(ChromeProxyMetric, self).AddResults(tab, results)
 
   def AddResultsForBypass(self, tab, results):