Report all missing path parameters, not just the first

This makes it possible to take remedial action such as copying the
parameters from the parent.

Even without this change, it is no longer necessary to symbolize the
keys or duplicate the attributes in request_path.

lib/her/errors.rb

@@ -1,11 +1,11 @@
 module Her
   module Errors
     class PathError < StandardError
-      attr_reader :missing_parameter
+      attr_reader :missing_parameters
 
-      def initialize(message, missing_parameter=nil)
+      def initialize(message, missing_parameters=nil)
         super(message)
-        @missing_parameter = missing_parameter
+        @missing_parameters = missing_parameters
       end
     end
 

lib/her/model/introspection.rb

@@ -15,7 +15,8 @@ def inspect
         resource_path = begin
           request_path
         rescue Her::Errors::PathError => e
-          "<unknown path, missing `#{e.missing_parameter}`>"
+          joined = e.missing_parameters.map { |m| "`#{m}`" }.join(", ")
+          "<unknown path, missing #{joined}>"
         end
 
         "#<#{self.class}(#{resource_path}) #{attributes.keys.map { |k| "#{k}=#{attribute_for_inspect(send(k))}" }.join(" ")}>"

lib/her/model/paths.rb

@@ -15,7 +15,7 @@ module Paths
       # @param [Hash] params An optional set of additional parameters for
       #   path construction. These will not override attributes of the resource.
       def request_path(params = {})
-        self.class.build_request_path(params.merge(attributes.dup))
+        self.class.build_request_path(params.merge(attributes))
       end
 
       module ClassMethods
@@ -104,15 +104,19 @@ def build_request_path(path=nil, parameters={})
             path.gsub!(/(\A|\/):id(\Z|\/)/, "\\1:#{primary_key}\\2")
           end
 
-          path.gsub(/:([\w_]+)/) do
-            # Look for :key or :_key, otherwise raise an exception
-            key = $1.to_sym
-            value = parameters.delete(key) || parameters.delete(:"_#{key}")
-            if value
-              Faraday::Utils.escape value
-            else
-              raise(Her::Errors::PathError.new("Missing :_#{$1} parameter to build the request path. Path is `#{path}`. Parameters are `#{parameters.symbolize_keys.inspect}`.", $1))
-            end
+          missing = []
+
+          result = path.gsub(/:([\w_]+)/) do
+            # Look for "key" or "_key", otherwise add to the missing list and raise below
+            value = parameters[$1] || parameters["_#{$1}"] || (missing.push($1) && $1)
+            Faraday::Utils.escape value
+          end
+
+          if missing.empty?
+            result
+          else
+            joined = missing.map { |m| ":_#{m}" }.join(", ")
+            raise Her::Errors::PathError.new("Missing #{joined} parameters to build the request path. Path is `#{path}`. Parameters are `#{parameters.symbolize_keys.inspect}`.", missing)
           end
         end
 

spec/model/paths_spec.rb

@@ -60,8 +60,8 @@
         end
 
         it "raises exceptions when building a path without required custom variables" do
-          Foo::User.collection_path "/organizations/:organization_id/utilisateurs"
-          expect { Foo::User.new(:id => "foo").request_path }.to raise_error(Her::Errors::PathError, "Missing :_organization_id parameter to build the request path. Path is `/organizations/:organization_id/utilisateurs/:id`. Parameters are `{:id=>\"foo\"}`.")
+          Foo::User.collection_path "/organizations/:organization_id/departments/:department_id/utilisateurs"
+          expect { Foo::User.new(:id => "foo").request_path }.to raise_error(Her::Errors::PathError, "Missing :_organization_id, :_department_id parameters to build the request path. Path is `/organizations/:organization_id/departments/:department_id/utilisateurs/:id`. Parameters are `{:id=>\"foo\"}`.")
         end
 
         it "escapes the variable values" do
@@ -121,12 +121,12 @@
 
         it "raises exceptions when building a path without required custom variables" do
           Foo::AdminUser.collection_path "/organizations/:organization_id/users"
-          expect { Foo::AdminUser.new(:id => "foo").request_path }.to raise_error(Her::Errors::PathError, "Missing :_organization_id parameter to build the request path. Path is `/organizations/:organization_id/users/:id`. Parameters are `{:id=>\"foo\"}`.")
+          expect { Foo::AdminUser.new(:id => "foo").request_path }.to raise_error(Her::Errors::PathError, "Missing :_organization_id parameters to build the request path. Path is `/organizations/:organization_id/users/:id`. Parameters are `{:id=>\"foo\"}`.")
         end
 
         it "raises exceptions when building a relative path without required custom variables" do
           Foo::AdminUser.collection_path "organizations/:organization_id/users"
-          expect { Foo::AdminUser.new(:id => "foo").request_path }.to raise_error(Her::Errors::PathError, "Missing :_organization_id parameter to build the request path. Path is `organizations/:organization_id/users/:id`. Parameters are `{:id=>\"foo\"}`.")
+          expect { Foo::AdminUser.new(:id => "foo").request_path }.to raise_error(Her::Errors::PathError, "Missing :_organization_id parameters to build the request path. Path is `organizations/:organization_id/users/:id`. Parameters are `{:id=>\"foo\"}`.")
         end
       end
     end