Fix error importing Widget on Custom Report page

https://bugzilla.redhat.com/show_bug.cgi?id=1442728

app/models/miq_policy/import_export.rb

@@ -1,6 +1,8 @@
 module MiqPolicy::ImportExport
   extend ActiveSupport::Concern
 
+  IMPORT_CLASS_NAMES = %w(MiqPolicy MiqPolicySet MiqAlert).freeze
+
   module ClassMethods
     def import_from_hash(policy, options = {})
       raise _("No Policy to Import") if policy.nil?

app/models/miq_report.rb

@@ -52,6 +52,7 @@ class MiqReport < ApplicationRecord
 
   GROUPINGS = [[:min, "Minimum"], [:avg, "Average"], [:max, "Maximum"], [:total, "Total"]]
   PIVOTS    = [[:min, "Minimum"], [:avg, "Average"], [:max, "Maximum"], [:total, "Total"]]
+  IMPORT_CLASS_NAMES = %w(MiqReport).freeze
 
   scope :for_user, lambda { |user|
     if user.admin_user?

app/models/miq_widget.rb

@@ -7,6 +7,7 @@ class MiqWidget < ApplicationRecord
   default_value_for :read_only, false
 
   DEFAULT_ROW_COUNT = 5
+  IMPORT_CLASS_NAMES = %w(MiqWidget).freeze
 
   belongs_to :resource, :polymorphic => true
   belongs_to :miq_schedule

app/models/mixins/yaml_import_export_mixin.rb

@@ -32,6 +32,7 @@ def import(fd, options = {})
       fd.rewind   # ensure to be at the beginning as the file is read multiple times
       begin
         reps = YAML.load(fd.read)
+        validate_import_data_class(reps)
       rescue Psych::SyntaxError => err
         _log.error("Failed to load from #{fd}: #{err}")
         raise "Invalid YAML file"
@@ -40,6 +41,14 @@ def import(fd, options = {})
       return reps, import_from_array(reps, options)
     end
 
+    def validate_import_data_class(data)
+      data_class_name = data.first.keys.first
+
+      unless self::IMPORT_CLASS_NAMES.include?(data_class_name)
+        raise _("Incorrect format: Expected #{self::IMPORT_CLASS_NAMES.join(", ")} and received #{data_class_name}.")
+      end
+    end
+
     # Import from an array of hash of the objects
     #
     # @param input [Array] The objects to be imported.

spec/models/mixins/yaml_import_export_mixin_spec.rb

@@ -42,10 +42,10 @@
   end
 
   context ".import" do
-    subject { test_class }
+    subject { MiqReport }
 
     it "valid YAML file" do
-      @fd = StringIO.new("---\na:")
+      @fd = StringIO.new("---\n- MiqReport:\n")
       # if it gets to import_from_array, then it did not choke on yml
       expect(subject).to receive(:import_from_array)
       subject.import(@fd)
@@ -56,4 +56,18 @@
       expect { subject.import(@fd) }.to raise_error("Invalid YAML file")
     end
   end
+
+  context ".validate_import_data_class" do
+    subject { MiqReport }
+
+    it "confirms valid class" do
+      @data = YAML.safe_load(StringIO.new("---\n- MiqReport:\n").read)
+      expect { subject.validate_import_data_class(@data) }.not_to raise_error
+    end
+
+    it "raises exception on invalid class" do
+      @data = YAML.safe_load(StringIO.new("---\n- MiqWidget:\n").read)
+      expect { subject.validate_import_data_class(@data) }.to raise_error("Incorrect format: Expected MiqReport and received MiqWidget.")
+    end
+  end
 end