Fix validations, don't hide database errors.

Fixes OUT-2525

Test Plan:
- Import a CSV with a long (>255 character) vendor_guid.
- Verify that on import, you get an email with an error referencing
  the specific line that failed.

Change-Id: I9b71e937666e404ac70d9ff0014d0f81ce541657
Reviewed-on: https://gerrit.instructure.com/168903
Tested-by: Jenkins
Reviewed-by: Neil Gupta <ngupta@instructure.com>
Reviewed-by: Augusto Callejas <acallejas@instructure.com>
QA-Review: Dariusz Dzien <ddzien@instructure.com>
Product-Review: Neil Gupta <ngupta@instructure.com>

app/models/learning_outcome.rb

@@ -47,6 +47,7 @@ class LearningOutcome < ActiveRecord::Base
 
   validates :description, length: { maximum: maximum_text_length, allow_nil: true, allow_blank: true }
   validates :short_description, length: { maximum: maximum_string_length }
+  validates :vendor_guid, length: { maximum: maximum_string_length, allow_nil: true }
   validates :display_name, length: { maximum: maximum_string_length, allow_nil: true, allow_blank: true }
   validates :calculation_method, inclusion: { in: CALCULATION_METHODS.keys,
     message: -> { t(

app/models/learning_outcome_group.rb

@@ -28,6 +28,7 @@ class LearningOutcomeGroup < ActiveRecord::Base
   belongs_to :context, polymorphic: [:account, :course]
 
   before_save :infer_defaults
+  validates :vendor_guid, length: { maximum: maximum_string_length, allow_nil: true }
   validates_length_of :description, :maximum => maximum_text_length, :allow_nil => true, :allow_blank => true
   validates_length_of :title, :maximum => maximum_string_length, :allow_nil => true, :allow_blank => true
   validates_presence_of :title, :workflow_state

lib/outcomes/csv_importer.rb

@@ -61,6 +61,8 @@ module Outcomes
         raise DataFormatError, I18n.t("Invalid CSV File")
       rescue ParseError => e
         raise DataFormatError, e.message
+      rescue ActiveRecord::StatementInvalid => e
+        raise DataFormatError, I18n.t("Database error (%{err})", err: e.message)
       end
       status = {
         errors: file_errors,

spec/lib/outcomes/csv_importer_spec.rb

@@ -428,6 +428,18 @@ describe Outcomes::CsvImporter do
       )
     end
 
+    it 'raises a line error when vendor_guid is too long' do
+      expect_import_error(
+        [
+          headers,
+          outcome_row(vendor_guid: 'long-' * 200),
+        ],
+        [
+          [2, "Vendor guid is too long (maximum is 255 characters)"],
+        ]
+      )
+    end
+
     it 'if a group receives invalid fields' do
       expect_import_error(
         [