[PATCH] Tests for stale responses from upstream that may be cached.

[Thorvaldur Thorvaldsson]

# HG changeset patch
# User Thorvaldur Thorvaldsson <thorvaldur.thorvaldsson at gmail.com>
# Date 1450275691 -3600
#      Wed Dec 16 15:21:31 2015 +0100
# Node ID 692075b59d386ffcbf1aff8e560488fd110d04f7
# Parent  dba758c045edbe010de380176235bea6b700367e
Tests for stale responses from upstream that may be cached.

The tests correspond to a patch that's been submitted to nginx-devel.

The test cases verify the caching and revalidation behaviour when:
  1) "proxy_cache_revalidate" directive is "on";
  2) the upstream response includes a "Cache-Control: max-age=0" header
     along with various combinations of ETag/Last-Modified headers.

There's also test for the case where there's no "proxy_cache_valid"
directive and also no "Cache-Control: max-age=0" header, or
X-Accel-Expires, or Expired header but still where the
"proxy_cache_revalidate" is on and the response includes an ETag header.

diff -r dba758c045ed -r 692075b59d38 proxy_cache_revalidate.t
--- a/proxy_cache_revalidate.t Thu Dec 17 17:18:07 2015 +0300
+++ b/proxy_cache_revalidate.t Wed Dec 16 15:21:31 2015 +0100
@@ -21,7 +21,7 @@
 select STDERR; $| = 1;
 select STDOUT; $| = 1;

-my $t = Test::Nginx->new()->has(qw/http proxy cache rewrite shmem/)->plan(23)
+my $t = Test::Nginx->new()->has(qw/http proxy cache rewrite shmem/)->plan(33)
  ->write_file_expand('nginx.conf', <<'EOF');

 %%TEST_GLOBALS%%
@@ -51,6 +51,11 @@

             add_header X-Cache-Status $upstream_cache_status;
         }
+        location /no-valid-directive/ {
+            proxy_pass    http://127.0.0.1:8081/etag-no-max-age/;
+            proxy_cache   one;
+            add_header X-Cache-Status $upstream_cache_status;
+        }
     }

     server {
@@ -68,6 +73,33 @@
             add_header X-If-Modified-Since $http_if_modified_since;
             return 201;
         }
+        location /stale-etag/ {
+            proxy_pass http://127.0.0.1:8081/;
+            proxy_hide_header Last-Modified;
+            add_header Cache-Control "max-age=0";
+        }
+        location /etag-no-max-age/ {
+            proxy_pass http://127.0.0.1:8081/;
+            proxy_hide_header Last-Modified;
+        }
+        location /stale-last-modified/ {
+            proxy_pass http://127.0.0.1:8081/;
+            proxy_hide_header ETag;
+            add_header Cache-Control "max-age=0";
+        }
+        location /stale-cannot-revalidate/ {
+            proxy_pass http://127.0.0.1:8081/;
+            proxy_hide_header ETag;
+            proxy_hide_header Last-Modified;
+            add_header Cache-Control "max-age=0";
+        }
+        location /stale-invalid-last-modified/ {
+            proxy_pass http://127.0.0.1:8081/;
+            proxy_hide_header ETag;
+            proxy_hide_header Last-Modified;
+            add_header Cache-Control "max-age=0";
+            add_header Last-Modified "invalid";
+        }
     }
 }

@@ -94,6 +126,31 @@
 like(http_get('/etag/t'), qr/X-Cache-Status: MISS.*SEE/ms, 'etag');
 like(http_get('/etag/t'), qr/X-Cache-Status: HIT.*SEE/ms, 'etag cached');

+my $CACHE_MISS = qr/X-Cache-Status: MISS.*?SEE/ms;
+my $CACHE_REVALIDATED = qr/X-Cache-Status: REVALIDATED.*?SEE/ms;
+
+like(http_get('/stale-etag/t'), $CACHE_MISS, 'stale etag');
+like(http_get('/stale-etag/t'), $CACHE_REVALIDATED, 'stale etag revalidated');
+
+like(http_get('/stale-last-modified/t'), $CACHE_MISS, 'stale last-modified');
+like(http_get('/stale-last-modified/t'), $CACHE_REVALIDATED,
+     'stale last-modified revalidated');
+
+like(http_get('/stale-cannot-revalidate/t'), $CACHE_MISS,
+     'stale cannot revalidate');
+like(http_get('/stale-cannot-revalidate/t'), $CACHE_MISS,
+     'stale cannot revalidate not cached');
+
+like(http_get('/stale-invalid-last-modified/t'), $CACHE_MISS,
+     'stale invalid last-modified');
+like(http_get('/stale-invalid-last-modified/t'), $CACHE_MISS,
+     'stale invalid last-modified not cached');
+
+like(http_get('/no-valid-directive/etag-no-max-age/t'), $CACHE_MISS,
+     'no cache-valid no max-age');
+like(http_get('/no-valid-directive/etag-no-max-age/t'), $CACHE_MISS,
+     'no cache-valid no max-age not cached');
+
 like(http_get('/etag/t2'), qr/X-Cache-Status: MISS.*SEE/ms, 'etag2');
 like(http_get('/etag/t2'), qr/X-Cache-Status: HIT.*SEE/ms, 'etag2 cached');