better errors / stats for Turnitin errors

This will help us what the story is with the sudden uptick in these
errors, and replace the "private method select for NilClass" errors with
a less-generic error

flag=none
refs INTEROP-7919

Test plan:
- add some debugging to the statsd code, e.g. add to
  initializers/inst_statsd.rb:
    class << InstStatsd::Statsd
      def increment(*args)
        puts "DEBUG STATSD increment: #{args.to_json}"
      end
    end
- get the contents of a failed job from prod from an employee sandbox.
  puts the `job.handler`. From this you will need:
  - get the referenced tool and copy the key and secret
  - copy the outcomes_response_json
- In a rails console you can then run
    Turnitin::OutcomeResponseProcessor.new(
      ContextExternalTool.new(key: KEY, secret: SECRET),
      Assignment.find(ANY_EXISTING_ASSIGNMENT), # Assignment.new might also work
      User.find(ANY_EXISTING_USER),
      OUTCOMES_RESPONSE_JSON_HASH
    ).update_originality_data(
      ANY_EXISTING_SUBMISSION, # Submission.new might also work
      "attachment_1234"
    )
- run the job and watch it increment the correct statsd counter and
  check /error_reports to check that the error is accurate. Both the
  stastsd counter and the error in error_reports identifies the message
  body as one of the known error messages

Change-Id: Ic73cd590de7ae0c304d6c4cc12b707692e9685dc
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/309945
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
QA-Review: Evan Battaglia <ebattaglia@instructure.com>
Build-Review: Jacob Burroughs <jburroughs@instructure.com>
Reviewed-by: Paul Gray <paul.gray@instructure.com>
Product-Review: Paul Gray <paul.gray@instructure.com>

Gemfile.rails61.lock.partial

@@ -321,8 +321,10 @@ PATH
       railties
     stringify_ids (1.0.0)
     turnitin_api (0.1.0)
+      activesupport
       faraday (~> 0.17.3)
       faraday_middleware (~> 0.8)
+      inst_statsd
       simple_oauth (~> 0.3)
     twitter (1.0.0)
       html_text_helper

Gemfile.rails70.lock.partial

@@ -321,8 +321,10 @@ PATH
       railties
     stringify_ids (1.0.0)
     turnitin_api (0.1.0)
+      activesupport
       faraday (~> 0.17.3)
       faraday_middleware (~> 0.8)
+      inst_statsd
       simple_oauth (~> 0.3)
     twitter (1.0.0)
       html_text_helper

gems/turnitin_api/lib/turnitin_api/outcomes_response_transformer.rb

@@ -18,6 +18,8 @@
 # with this program. If not, see <http://www.gnu.org/licenses/>.
 
 require "simple_oauth"
+require "inst_statsd"
+require "active_support/core_ext/string/filters"
 
 module TurnitinApi
   class OutcomesResponseTransformer
@@ -27,6 +29,16 @@ module TurnitinApi
 
     attr_accessor :outcomes_response_json, :key, :lti_params
 
+    class InvalidResponse < StandardError; end
+
+    KNOWN_ERROR_MESSAGES = {
+      api_login_failed: 'API Login failed: "oauth_signature" incorrect credentials and/or signature calculation',
+      api_product_inactive: "API product inactive or expired",
+      oauth_consumer_key: '"oauth_consumer_key" value is missing or not valid.',
+      not_enabled: "This integration is not currently enabled. Contact your account administrator.",
+      not_found: "The requested Object Result could not be found."
+    }.freeze
+
     def initialize(key, secret, lti_params, outcomes_response_json)
       @key = key
       @secret = secret
@@ -35,7 +47,21 @@ module TurnitinApi
     end
 
     def response
-      @response ||= make_call(outcomes_response_json["outcomes_tool_placement_url"])
+      @response ||= make_call(outcomes_response_json["outcomes_tool_placement_url"]).tap do |resp|
+        if (200..299).cover?(resp.status)
+          resp
+        else
+          error_msg = KNOWN_ERROR_MESSAGES.find { |_name, text| resp.body&.include?(text) }&.first
+          error_msg ||= :unknown
+
+          stats_tags = { status: resp.status, message: error_msg }
+          InstStatsd::Statsd.increment("lti.tii.outcomes_response_bad", tags: stats_tags)
+
+          raise InvalidResponse,
+                "TII returned #{resp.status} code, content length=#{resp.body&.length}, " \
+                "message #{error_msg}, body #{resp.body&.truncate(100).inspect}"
+        end
+      end
     end
 
     # download original

gems/turnitin_api/spec/outcomes_response_transformer_spec.rb

@@ -42,14 +42,65 @@ describe TurnitinApi::OutcomesResponseTransformer do
   end
 
   describe "response" do
+    let(:stubbed_response) do
+      {
+        status: 200,
+        body: fixture("outcome_detailed_response.json"),
+        headers: { "Content-Type" => "application/json" }
+      }
+    end
+
     before do
       stub_request(:post, "http://turnitin.com/api/lti/1p0/outcome_tool_data/4321")
-        .to_return(status: 200, body: fixture("outcome_detailed_response.json"), headers: { "Content-Type" => "application/json" })
+        .to_return(stubbed_response)
     end
 
     it "returns expected json response" do
       expect(subject.response.body["outcome_originalfile"]["launch_url"]).to eq "https://turnitin.com/api/lti/1p0/dow...72874634?lang="
     end
+
+    context "when TII returns a non-2xx response" do
+      let(:stubbed_body) { "TII errored out oh no " * 10 }
+      let(:stubbed_response) { { status: 403, body: stubbed_body } }
+      let(:truncated_body) { stubbed_body.truncate(100).inspect }
+
+      it "raises an InvalidResponse error with the status code and content length" do
+        expect { subject.response }.to raise_error(
+          described_class::InvalidResponse,
+          "TII returned 403 code, content length=#{stubbed_body.length}, message unknown, body #{truncated_body}"
+        )
+      end
+
+      it "increments a statsd counter which includes the status code" do
+        allow(InstStatsd::Statsd).to receive(:increment)
+        expect { subject.response }.to raise_error(described_class::InvalidResponse)
+        expect(InstStatsd::Statsd).to have_received(:increment).with(
+          "lti.tii.outcomes_response_bad",
+          tags: { status: 403, message: :unknown }
+        )
+      end
+
+      context "when the response body is one of the known recognized ones" do
+        let(:stubbed_body) { "bla bla API product inactive or expired bla bla" }
+        let(:stubbed_response) { { status: 401, body: stubbed_body } }
+
+        it "identifies known responses in the InvalidResponse error" do
+          expect { subject.response }.to raise_error(
+            described_class::InvalidResponse,
+            "TII returned 401 code, content length=47, message api_product_inactive, body #{truncated_body}"
+          )
+        end
+
+        it "identifies known responses in the statsd counter" do
+          allow(InstStatsd::Statsd).to receive(:increment)
+          expect { subject.response }.to raise_error(described_class::InvalidResponse)
+          expect(InstStatsd::Statsd).to have_received(:increment).with(
+            "lti.tii.outcomes_response_bad",
+            tags: { status: 401, message: :api_product_inactive }
+          )
+        end
+      end
+    end
   end
 
   describe "original_submission" do

gems/turnitin_api/turnitin_api.gemspec

@@ -15,8 +15,10 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.add_dependency "activesupport"
   spec.add_dependency "faraday", "~> 0.17.3"
   spec.add_dependency "faraday_middleware", "~> 0.8"
+  spec.add_dependency "inst_statsd"
   spec.add_dependency "simple_oauth", "~> 0.3"
 
   spec.add_development_dependency "bundler", "~> 2.2"