From ee93eab2f77a484ceb6c81e0f2d18f90dfde036c Mon Sep 17 00:00:00 2001
From: Alex Moinet <Alex.moinet@yahoo.co.uk>
Date: Mon, 2 Oct 2017 19:13:47 +0100
Subject: [PATCH] Add 'did you mean' suggestions to metadata (#372)

---
 lib/bugsnag/configuration.rb              |  2 ++
 lib/bugsnag/middleware/suggestion_data.rb | 30 +++++++++++++++++++
 spec/middleware_spec.rb                   | 36 ++++++++++++++++++++++-
 spec/spec_helper.rb                       |  8 +++++
 4 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 lib/bugsnag/middleware/suggestion_data.rb

diff --git a/lib/bugsnag/configuration.rb b/lib/bugsnag/configuration.rb
index cb922a356..633da956b 100644
--- a/lib/bugsnag/configuration.rb
+++ b/lib/bugsnag/configuration.rb
@@ -5,6 +5,7 @@
 require "bugsnag/middleware/callbacks"
 require "bugsnag/middleware/exception_meta_data"
 require "bugsnag/middleware/ignore_error_class"
+require "bugsnag/middleware/suggestion_data"
 require "bugsnag/middleware/classify_error"
 
 module Bugsnag
@@ -74,6 +75,7 @@ def initialize
       self.internal_middleware = Bugsnag::MiddlewareStack.new
       self.internal_middleware.use Bugsnag::Middleware::ExceptionMetaData
       self.internal_middleware.use Bugsnag::Middleware::IgnoreErrorClass
+      self.internal_middleware.use Bugsnag::Middleware::SuggestionData
       self.internal_middleware.use Bugsnag::Middleware::ClassifyError
 
       self.middleware = Bugsnag::MiddlewareStack.new
diff --git a/lib/bugsnag/middleware/suggestion_data.rb b/lib/bugsnag/middleware/suggestion_data.rb
new file mode 100644
index 000000000..696af1171
--- /dev/null
+++ b/lib/bugsnag/middleware/suggestion_data.rb
@@ -0,0 +1,30 @@
+module Bugsnag::Middleware
+  class SuggestionData
+
+    CAPTURE_REGEX = /Did you mean\?([\s\S]+)$/
+    DELIMITER = "\n"
+
+    def initialize(bugsnag)
+      @bugsnag = bugsnag
+    end
+
+    def call(report)
+      matches = []
+      report.raw_exceptions.each do |exception|
+        match = CAPTURE_REGEX.match(exception.message)
+        next unless match
+
+        suggestions = match.captures[0].split(DELIMITER)
+        matches.concat suggestions.map{ |suggestion| suggestion.strip }
+      end
+
+      if matches.size == 1
+        report.add_tab(:error, {:suggestion => matches.first})
+      elsif matches.size > 1
+        report.add_tab(:error, {:suggestions => matches})
+      end
+
+      @bugsnag.call(report)
+    end
+  end
+end
diff --git a/spec/middleware_spec.rb b/spec/middleware_spec.rb
index 267669e4f..7f8d23aa7 100644
--- a/spec/middleware_spec.rb
+++ b/spec/middleware_spec.rb
@@ -178,6 +178,41 @@ def call(report)
     }
   end
 
+  if ruby_version_greater_equal?("2.3.0")
+    context "with a ruby version >= 2.3.0" do
+      it "attaches did you mean metadata when necessary" do
+        begin
+          "Test".starts_with? "T"
+        rescue Exception => e
+          Bugsnag.notify(e)
+        end
+
+        expect(Bugsnag).to have_sent_notification{ |payload|
+          event = get_event_from_payload(payload)
+          expect(event["metaData"]["error"]).to_not be_nil
+          expect(event["metaData"]["error"]).to eq({"suggestion" => "start_with?"})
+        }
+      end
+    end
+  end
+
+  context "with a ruby version < 2.3.0" do
+    if !ruby_version_greater_equal?("2.3.0")
+      it "doesn't attach did you mean metadata" do
+        begin
+          "Test".starts_with? "T"
+        rescue Exception => e
+          Bugsnag.notify(e)
+        end
+
+        expect(Bugsnag).to have_sent_notification{ |payload|
+          event = get_event_from_payload(payload)
+          expect(event["metaData"]["error"]).to be_nil
+        }
+      end
+    end
+  end
+
   it "doesn't allow handledState properties to be changed in middleware" do
     HandledStateChanger = Class.new do
       def initialize(bugsnag)
@@ -216,5 +251,4 @@ def call(report)
       })
     }
   end
-
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 549e8e605..7e91198fb 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -30,6 +30,14 @@ def notify_test_exception(*args)
   Bugsnag.notify(RuntimeError.new("test message"), *args)
 end
 
+def ruby_version_greater_equal?(version)
+  current_version = RUBY_VERSION.split "."
+  target_version = version.split "."
+  (Integer(current_version[0]) >= Integer(target_version[0])) &&
+    (Integer(current_version[1]) >= Integer(target_version[1])) &&
+    (Integer(current_version[2]) >= Integer(target_version[2]))
+end
+
 RSpec.configure do |config|
   config.order = "random"