Merge pull request #1483 from jeremyevans/lint-response-array

Make Rack::Lint check response is array with 3 elements

2 files changed, 25 insertions, 1 deletions

diff --git a/lib/rack/lint.rb b/lib/rack/lint.rb
index 9b739f98..20491c36 100644
--- a/lib/rack/lint.rb
+++ b/lib/rack/lint.rb
@@ -48,7 +48,15 @@ module Rack
       env[RACK_ERRORS] = ErrorWrapper.new(env[RACK_ERRORS])
 
       ## and returns an Array of exactly three values:
-      status, headers, @body = @app.call(env)
+      ary = @app.call(env)
+      assert("response #{ary.inspect} is not an Array , but #{ary.class}") {
+        ary.kind_of? Array
+      }
+      assert("response array #{ary.inspect} has #{ary.size} elements instead of 3") {
+        ary.size == 3
+      }
+
+      status, headers, @body = ary
       ## The *status*,
       check_status status
       ## the *headers*,
diff --git a/test/spec_lint.rb b/test/spec_lint.rb
index 192f260f..82de1c1d 100644
--- a/test/spec_lint.rb
+++ b/test/spec_lint.rb
@@ -163,6 +163,22 @@ describe Rack::Lint do
       message.must_match(/does not respond to #puts/)
   end
 
+  it "notice response errors" do
+    lambda {
+      Rack::Lint.new(lambda { |env|
+                       ""
+                     }).call(env({}))
+    }.must_raise(Rack::Lint::LintError).
+      message.must_include('response "" is not an Array , but String')
+
+    lambda {
+      Rack::Lint.new(lambda { |env|
+                       [nil, nil, nil, nil]
+                     }).call(env({}))
+    }.must_raise(Rack::Lint::LintError).
+      message.must_include('response array [nil, nil, nil, nil] has 4 elements instead of 3')
+  end
+
   it "notice status errors" do
     lambda {
       Rack::Lint.new(lambda { |env|