Make sure all responses from the API are hashes or arrays

lib/her/errors.rb

@@ -2,5 +2,6 @@ module Her
   module Errors
     class PathError < StandardError; end;
     class AssociationUnknownError < StandardError; end;
+    class ParseError < StandardError; end;
   end
 end

lib/her/middleware/first_level_parse_json.rb

@@ -8,6 +8,8 @@ class FirstLevelParseJSON < Faraday::Response::Middleware
       # @return [Mixed] the parsed response
       def parse(body)
         json = MultiJson.load(body, :symbolize_keys => true)
+        raise Her::Errors::ParseError, "Response from the API must behave like a Hash or an Array (last was: #{json.inspect})" unless json.is_a?(Hash) or json.is_a?(Array)
+
         errors = json.delete(:errors) || {}
         metadata = json.delete(:metadata) || []
         {

lib/her/middleware/second_level_parse_json.rb

@@ -9,6 +9,8 @@ class SecondLevelParseJSON < Faraday::Response::Middleware
       # @return [Mixed] the parsed response
       def parse(body)
         json = MultiJson.load(body, :symbolize_keys => true)
+        raise Her::Errors::ParseError, "Response from the API must behave like a Hash or an Array (last was: #{json.inspect})" unless json.is_a?(Hash) or json.is_a?(Array)
+
         {
           :data => json[:data],
           :errors => json[:errors],

spec/middleware/first_level_parse_json_spec.rb

@@ -6,6 +6,7 @@
   let(:body_without_errors) { "{\"id\": 1, \"name\": \"Tobias Fünke\", \"metadata\": 3}" }
   let(:body_with_errors) { "{\"id\": 1, \"name\": \"Tobias Fünke\", \"errors\": { \"name\": [ \"not_valid\", \"should_be_present\" ] }, \"metadata\": 3}" }
   let(:body_with_malformed_json) { "wut." }
+  let(:body_with_invalid_json) { "true" }
 
   it "parses body as json" do
     subject.parse(body_without_errors).tap do |json|
@@ -35,6 +36,10 @@
     expect { subject.parse(body_with_malformed_json) }.to raise_error(MultiJson::LoadError)
   end
 
+  it 'ensures that invalid JSON throws an exception' do
+    expect { subject.parse(body_with_invalid_json) }.to raise_error(Her::Errors::ParseError, "Response from the API must behave like a Hash or an Array (last was: true)")
+  end
+
   context 'with status code 204' do
     it 'returns an empty body' do
       env = { :status => 204 }

spec/middleware/second_level_parse_json_spec.rb

@@ -3,23 +3,33 @@
 
 describe Her::Middleware::SecondLevelParseJSON do
   subject { described_class.new }
-  let(:body) { "{\"data\": 1, \"errors\": 2, \"metadata\": 3}" }
 
-  it "parses body as json" do
-    subject.parse(body).tap do |json|
-      json[:data].should == 1
-      json[:errors].should == 2
-      json[:metadata].should == 3
+  context "with valid JSON body" do
+    let(:body) { "{\"data\": 1, \"errors\": 2, \"metadata\": 3}" }
+    it "parses body as json" do
+      subject.parse(body).tap do |json|
+        json[:data].should == 1
+        json[:errors].should == 2
+        json[:metadata].should == 3
+      end
+    end
+
+    it "parses :body key as json in the env hash" do
+      env = { :body => body }
+      subject.on_complete(env)
+      env[:body].tap do |json|
+        json[:data].should == 1
+        json[:errors].should == 2
+        json[:metadata].should == 3
+      end
     end
   end
 
-  it "parses :body key as json in the env hash" do
-    env = { :body => body }
-    subject.on_complete(env)
-    env[:body].tap do |json|
-      json[:data].should == 1
-      json[:errors].should == 2
-      json[:metadata].should == 3
+  context "with invalid JSON body" do
+    let(:body) { '"foo"' }
+    it 'ensures that invalid JSON throws an exception' do
+      expect { subject.parse(body) }.to raise_error(Her::Errors::ParseError, "Response from the API must behave like a Hash or an Array (last was: \"foo\")")
     end
   end
+
 end