Ensure the 'Cache-Control: max-age' is validated

Author: aw

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+#  0.1.18 (2015-05-01)
+
+  * Ensure the 'Cache-Control: max-age' is validated
+  * Add regression tests
+  * Update documentation
+
 ## 0.1.17 (2015-04-30)
 
   * Return the proper 'Age' header and ignore the 'public' control directive

README.md

@@ -49,7 +49,7 @@ HTTP Caching request.
 | :------------------------| :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
 | **Are the headers cached?** | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
 | **Must revalidate?** | - | - | - | - | 0 | 0 | 0 | 1 | - |
-| **No-cache or max-age 0?** | - | - | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
+| **No-cache or max-age reached?** | - | - | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
 | **Do Etags/If-None-Match match?** | - | - | 0 | 1 | 0 | 1 | - | - | - |
 | **Is the cached data expired?** | - | - | 0 | 0 | 1 | 1 | 1 | 1 | - |
 | **Is there an if-only-cached header?** | 0 | 1 | - | - | - | - | - | - | - |
@@ -125,6 +125,7 @@ To run the tests, type:
 
 ## TODO
 
+  * Validation of `s-maxage` [response header](https://tools.ietf.org/html/rfc7234#section-5.2.2.9)
   * Handling `Vary` header and different representations for the same resource
   * Handling `206 (Partial)` and `Range` headers for resuming downloads
   * Handling `Cache-Control: private` headers

cache_rules.gemspec

@@ -6,7 +6,7 @@ require 'date'
 
 Gem::Specification.new do |s|
   s.name        = 'cache_rules'
-  s.version     = '0.1.17'
+  s.version     = '0.1.18'
 
   s.date        = Date.today.to_s
 

lib/validations.rb

@@ -47,7 +47,11 @@ def validate_expired?(headers)
 
     response_is_fresh = freshness_lifetime.to_i > current_age
 
-    to_bit { response_is_fresh != true }
+    return 1 if headers[:cached]['Cache-Control'] &&
+                  headers[:cached]['Cache-Control']['max-age'] &&
+                    current_age > headers[:cached]['Cache-Control']['max-age']['token'].to_i
+
+    to_bit { (response_is_fresh != true) }
   end
 
   def validate_only_if_cached?(headers)
@@ -85,8 +89,16 @@ def validate_no_cache?(headers)
 
     # Must revalidate if this request header exists
     # source: https://tools.ietf.org/html/rfc7234#section-5.2.1.4
-    return 1 if (( request = request_headers['Cache-Control'] )) &&
-      request_headers['Cache-Control']['no-cache']
+    if request_headers['Cache-Control']
+      _, current_age = helper_freshness_lifetime.call cached_headers
+
+      # If max-age is 0 or if the current age is above the max-age and max-stale isn't set
+      # source: https://tools.ietf.org/html/rfc7234#section-5.2.1.1
+      return 1 if (( request = request_headers['Cache-Control'] )) &&
+        request['no-cache'] ||
+        (!request['max-stale'] && request['max-age'] &&
+          (request['max-age']['token'].to_s == "0" || current_age > request['max-age']['token'].to_i))
+    end
 
     # source: https://tools.ietf.org/html/rfc7234#section-5.2.2.2
     # source: https://tools.ietf.org/html/rfc7234#section-3.2

test/test_regressions.rb

@@ -8,9 +8,11 @@ class TestRegressions < MiniTest::Test
   def setup
     @cached_headers = {
       :cached => {
+        "Age"               => "99999",
         "Date"              => {"httpdate"=>"Thu, 01 Jan 2015 07:03:45 GMT", "timestamp"=>1420095825},
         "Cache-Control"     => {
-          "public"          => {"token"=>nil, "quoted_string"=>nil}
+          "public"          => {"token"=>nil, "quoted_string"=>nil},
+          "max-age"         => {"token"=>"10", "quoted_string"=>nil}
         },
         "X-Cache-Req-Date"  => {"httpdate"=>"Sat, 03 Jan 2015 07:03:45 GMT", "timestamp"=>1420268625},
         "X-Cache-Res-Date"  => {"httpdate"=>"Sat, 03 Jan 2015 07:03:45 GMT", "timestamp"=>1420268625}
@@ -44,4 +46,24 @@ def test_bugfix_8_errors_caused_by_empty_http_headers
     assert_equal isnil,   []
     assert_equal isempty, []
   end
+
+  # https://github.com/aw/CacheRules/issues/10
+  def test_bugfix_10_request_header_max_age_is_checked
+    request_maxage = CacheRules.validate_no_cache?({
+      :cached   => @cached_headers[:cached],
+      :request  => {"Cache-Control" => {"max-age" => {"token"=>0, "quoted_string"=>nil} } }
+    })
+    current = CacheRules.validate_no_cache?({
+      :cached   => @cached_headers[:cached],
+      :request  => {"Cache-Control" => {"max-age" => {"token"=>1000, "quoted_string"=>nil} } }
+    })
+    cached_max_age = CacheRules.validate_expired?({
+      :cached   => @cached_headers[:cached],
+      :request  => {}
+    })
+
+    assert_equal 1, request_maxage
+    assert_equal 1, current
+    assert_equal 1, cached_max_age
+  end
 end

test/test_validations.rb

@@ -164,7 +164,7 @@ def test_must_revalidate
   def test_no_cache
     headers1 = {
       :request => {'Cache-Control' => {'no-cache'=>{'token'=>nil}}},
-      :cached => {'Cache-Control' => {}}
+      :cached => {}
     }
     headers2 = {
       :request => {},