fix import of quiz durations with time units specified

durations may be specified with a single digit unit prefix
e.g. M# (minutes), H# (hours), D# (days)

if no unit is specified, seconds is assumed

fixes #CNVS-1283

test plan:
 * perform a Blackboard Vista/CE/WebCT course migration
   - the course should include an assessment with a time limit
 * verify that the imported quiz has the correct time limit

Change-Id: I02c9144540eadf5a43c623a4ffeb78e22c3786e5
Reviewed-on: https://gerrit.instructure.com/15944
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Bracken Mosbacker <bracken@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>

vendor/plugins/qti_exporter/lib/qti/assessment_test_converter.rb

@@ -87,9 +87,7 @@ class AssessmentTestConverter
     @quiz[:quiz_name] = @quiz[:title]
     @quiz[:migration_id] = get_node_att(doc, 'assessmentTest', 'identifier')
     if limit = doc.at_css('timeLimits')
-      limit = limit['maxTime'].to_i
-      #instructure uses minutes, QTI uses seconds
-      @quiz[:time_limit] = limit / 60
+      @quiz[:time_limit] = AssessmentTestConverter.parse_time_limit(limit['maxTime'])
     end
     if part = doc.at_css('testPart[identifier=BaseTestPart]')
       if control = part.at_css('itemSessionControl')
@@ -112,6 +110,23 @@ class AssessmentTestConverter
     end
   end
 
+  def self.parse_time_limit(time_limit)
+    limit = 0
+    time_indicator = time_limit[0..0].downcase if time_limit.length > 0
+    if time_indicator == 'd'
+      limit = 24 * 60 * time_limit[1..-1].to_i
+    elsif time_indicator == 'h'
+      limit = 60 * time_limit[1..-1].to_i
+    elsif time_indicator == 'm'
+      limit = time_limit[1..-1].to_i
+    else
+      #instructure uses minutes, QTI uses seconds
+      limit = time_limit.to_i / 60
+    end
+
+    limit
+  end
+
   def process_section(section)
     group = nil
     questions_list = @quiz[:questions]

vendor/plugins/qti_exporter/spec_canvas/lib/qti/assessment_test_converter_spec.rb

@@ -0,0 +1,21 @@
+require File.expand_path(File.dirname(__FILE__) + '/../../qti_helper')
+
+describe Qti::AssessmentTestConverter do
+  it "should interpret duration strings that include units" do
+    assess = Qti::AssessmentTestConverter
+
+    minutes_in_hour = 60
+    minutes_in_day = 24 * minutes_in_hour
+
+    assess.parse_time_limit("D1").should == minutes_in_day
+    assess.parse_time_limit("d2").should == 2 * minutes_in_day
+    assess.parse_time_limit("H4").should == 4 * minutes_in_hour
+    assess.parse_time_limit("h1").should == minutes_in_hour
+    assess.parse_time_limit("M120").should == 120
+    assess.parse_time_limit("m14").should == 14
+
+    #Canvas uses minutes, QTI uses seconds
+    assess.parse_time_limit("60").should == 1
+    assess.parse_time_limit("3600").should == 60
+  end
+end