Allow canvas extension placements in LTI registration

fixes INTEROP-8301

flag = lti_dynamic_registration

test plan:
- specs pass

Change-Id: I7639e8bd92bdf8e37ed9f1c4e30b4a75d724044e
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/332641
Reviewed-by: Evan Battaglia <ebattaglia@instructure.com>
QA-Review: Tucker Mcknight <tmcknight@instructure.com>
Product-Review: Tucker Mcknight <tmcknight@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>

app/models/lti/ims/registration.rb

@@ -121,7 +121,7 @@ class Lti::IMS::Registration < ApplicationRecord
       else
         message["placements"].map do |placement|
           {
-            placement:,
+            placement: canvas_placement_name(placement),
             enabled: true,
             message_type: message["type"],
             target_link_uri: message["target_link_uri"],
@@ -207,4 +207,14 @@ class Lti::IMS::Registration < ApplicationRecord
       config_errors.is_a?(Hash) ? config_errors.to_json : config_errors
     )
   end
+
+  def canvas_placement_name(placement)
+    # IMS placement names that have different names in Canvas
+    return "link_selection" if placement == "ContentArea"
+    return "editor_button" if placement == "RichTextEditor"
+
+    # Otherwise, remove our URL prefix from the Canvas-specific placements
+    canvas_extension = "https://#{CANVAS_EXTENSION_LABEL}/lti/"
+    placement.start_with?(canvas_extension) ? placement.sub(canvas_extension, "") : placement
+  end
 end

spec/models/lti/ims/registration_spec.rb

@@ -281,7 +281,13 @@ module Lti::IMS
               "foo" => "bar"
             },
             icon_uri: "http://example.com/icon.png",
-            placements: ["global_navigation", "course_navigation"],
+            placements: [
+              "https://canvas.instructure.com/lti/assignment_edit",
+              "global_navigation",
+              "course_navigation",
+              "ContentArea",
+              "RichTextEditor",
+            ],
           }],
           claims: []
         }
@@ -290,26 +296,28 @@ module Lti::IMS
       subject { registration.placements }
 
       context "convert messages to placements" do
-        it do
+        it "accepts valid placements" do
+          canvas_placement_hash = {
+            custom_fields: { "foo" => "bar" },
+            enabled: true,
+            icon_url: "http://example.com/icon.png",
+            message_type: "LtiResourceLinkRequest",
+            target_link_uri: "http://example.com/launch"
+          }
           expect(subject).to eq [
-            {
-              custom_fields: { "foo" => "bar" },
-              enabled: true,
-              icon_url: "http://example.com/icon.png",
-              message_type: "LtiResourceLinkRequest",
-              placement: "global_navigation",
-              target_link_uri: "http://example.com/launch"
-            },
-            {
-              custom_fields: { "foo" => "bar" },
-              enabled: true,
-              icon_url: "http://example.com/icon.png",
-              message_type: "LtiResourceLinkRequest",
-              placement: "course_navigation",
-              target_link_uri: "http://example.com/launch"
-            }
+            canvas_placement_hash.merge(placement: "assignment_edit"),
+            canvas_placement_hash.merge(placement: "global_navigation"),
+            canvas_placement_hash.merge(placement: "course_navigation"),
+            canvas_placement_hash.merge(placement: "link_selection"),
+            canvas_placement_hash.merge(placement: "editor_button"),
           ]
         end
+
+        it "rejects invalid placements" do
+          bad_placement_name = "course_navigationhttps://canvas.instructure.com/lti/"
+          registration.lti_tool_configuration["messages"].first["placements"] << bad_placement_name
+          expect { registration.save! }.to raise_error(ActiveRecord::RecordInvalid)
+        end
       end
     end