Allow empty array to be used as a params in get requests.

Fixes #469

lib/httparty/hash_conversions.rb

@@ -26,7 +26,11 @@ def self.normalize_param(key, value)
       stack = []
 
       if value.respond_to?(:to_ary)
-        param << value.to_ary.map { |element| normalize_param("#{key}[]", element) }.join
+        param << if value.empty?
+                   "#{key}[]=&"
+                 else
+                   value.to_ary.map { |element| normalize_param("#{key}[]", element) }.join
+                 end
       elsif value.respond_to?(:to_hash)
         stack << [key, value.to_hash]
       else

lib/httparty/request.rb

@@ -78,7 +78,11 @@ def uri
 
       # avoid double query string on redirects [#12]
       unless redirect
-        new_uri.query = query_string(new_uri)
+        possible_query_string = query_string(new_uri)
+
+        if possible_query_string != nil && possible_query_string != ""
+          new_uri.query = query_string(new_uri)
+        end
       end
 
       unless SupportedURISchemes.include? new_uri.scheme
@@ -201,7 +205,9 @@ def query_string(uri)
         query_string_parts << options[:query] unless options[:query].nil?
       end
 
-      query_string_parts.reject!(&:empty?) unless query_string_parts == [""]
+      query_string_parts.reject! { |part|
+        part.is_a?(Array) || part.empty?
+      } unless query_string_parts == [""]
       query_string_parts.size > 0 ? query_string_parts.join('&') : nil
     end
 

spec/httparty/hash_conversions_spec.rb

@@ -22,6 +22,14 @@
       end
     end
 
+    context "value is an empty array" do
+      it "creates a params string" do
+        expect(
+          HTTParty::HashConversions.normalize_param(:people, [])
+        ).to eq("people[]=&")
+      end
+    end
+
     context "value is hash" do
       it "creates a params string" do
         expect(

spec/httparty/request_spec.rb

@@ -56,6 +56,24 @@
       expect(request.connection_adapter).to eq(my_adapter)
     end
 
+    context "when using a query string" do
+      context "and it has an empty array" do
+        it "sets correct query string" do
+          request = HTTParty::Request.new(Net::HTTP::Get, 'http://google.com', query: { fake_array: [] })
+
+          expect(request.uri).to eq(URI.parse("http://google.com/?fake_array[]="))
+        end
+      end
+
+      context "when sending an array with only one element" do
+        it "sets correct query" do
+          request = HTTParty::Request.new(Net::HTTP::Get, 'http://google.com', query: { fake_array: [1] })
+
+          expect(request.uri).to eq(URI.parse("http://google.com/?fake_array[]=1"))
+        end
+      end
+    end
+
     context "when basic authentication credentials provided in uri" do
       context "when basic auth options wasn't set explicitly" do
         it "sets basic auth from uri" do
@@ -221,10 +239,10 @@
       end
 
       it "respects the query string normalization proc" do
-        empty_proc = lambda {|qs| ""}
+        empty_proc = lambda {|qs| "I"}
         @request.options[:query_string_normalizer] = empty_proc
         @request.options[:query] = {foo: :bar}
-        expect(CGI.unescape(@request.uri.query)).to eq("")
+        expect(CGI.unescape(@request.uri.query)).to eq("I")
       end
 
       it "does not append an ampersand when queries are embedded in paths" do