Don't route /rails/info request to Ember

Closes [#449].

> When mounting an Ember CLI app via `mount_ember_app`, the catch-all
> routes defined by Ember CLI Rails also catch requests to two of Rails'
> magic routes:
>
> 1. `/rails/info/routes` (which is also redirected to from `/rails/info`)
> 2. `/rails/info/properties`
>
> This adds another constraint to the mounted Ember app that will ignore
> requests with a path starting with `/rails/info`.
>
> @stevenharman

[#449]: #449

Author: seanpdoyle

CHANGELOG.md

@@ -1,6 +1,8 @@
 master
 ------
 
+* Don't route requests to `/rails/info` through the mounted Ember application.
+
 0.7.4
 -----
 

lib/ember_cli/ember_constraint.rb

@@ -0,0 +1,19 @@
+module EmberCli
+  class EmberConstraint
+    def matches?(request)
+      html_request?(request) && !rails_info_request?(request)
+    end
+
+    private
+
+    def rails_info_request?(request)
+      request.fullpath.start_with?("/rails/info")
+    end
+
+    def html_request?(request)
+      index = request.format.to_s =~ /html/ || -1
+
+      index > -1
+    end
+  end
+end

lib/ember_cli/html_constraint.rb

@@ -1,4 +1,4 @@
-require "ember_cli/html_constraint"
+require "ember_cli/ember_constraint"
 
 module ActionDispatch
   module Routing
@@ -14,7 +14,7 @@ def mount_ember_app(app_name, to:, **options)
           format: :html,
         )
 
-        scope constraints: ::EmberCli::HtmlConstraint.new do
+        scope constraints: ::EmberCli::EmberConstraint.new do
           get("#{to}(*rest)", routing_options)
         end
 

lib/ember_cli/route_helpers.rb

@@ -0,0 +1,57 @@
+require "ember_cli/ember_constraint"
+
+describe EmberCli::EmberConstraint do
+  describe "#matches?" do
+    context %{when the format is "html"} do
+      context "when the request path is for a Rails info page" do
+        it "returns false" do
+          constraint = EmberCli::EmberConstraint.new
+          request = build_html_request("/rails/info")
+
+          expect(constraint.matches?(request)).to be false
+        end
+      end
+
+      context "when the request path is not for a Rails info page" do
+        it "returns true" do
+          constraint = EmberCli::EmberConstraint.new
+          request = build_html_request("/foo")
+
+          expect(constraint.matches?(request)).to be true
+        end
+      end
+    end
+
+    context %{when the format isn't "html"} do
+      it "return false" do
+        constraint = EmberCli::EmberConstraint.new
+        request = build_json_request
+
+        expect(constraint.matches?(request)).to be false
+      end
+    end
+
+    context %"when the format is empty or nil" do
+      it "return false" do
+        constraint = EmberCli::EmberConstraint.new
+        nil_request = build_request(format: nil)
+        empty_request = build_request(format: "")
+
+        expect(constraint.matches?(nil_request)).to be false
+        expect(constraint.matches?(empty_request)).to be false
+      end
+    end
+  end
+
+  def build_request(format:, fullpath: :ignored)
+    double(format: format, fullpath: fullpath)
+  end
+
+  def build_html_request(fullpath)
+    build_request(format: :html, fullpath: fullpath)
+  end
+
+  def build_json_request
+    build_request(format: :json)
+  end
+end