YAMLLoader: support Array for inherit

lib/review/yamlloader.rb

@@ -5,30 +5,42 @@ class YAMLLoader
     def initialize
     end
 
+    # load YAML files
+    #
+    # `inherit: [3.yml, 6.yml]` in 7.yml; `inherit: [1.yml, 2.yml]` in 3.yml; `inherit: [4.yml, 5.yml]` in 6.yml
+    #    => 7.yml > 6.yml > 5.yml > 4.yml > 3.yml > 2.yml > 1.yml
+    #
     def load_file(yamlfile)
-      current_file = yamlfile
+      file_queue = [File.expand_path(yamlfile)]
       loaded_files = {}
       yaml = {}
 
       loop do
-        current_yaml = YAML.load_file(current_file)
-        yaml = current_yaml.deep_merge(yaml)
-
         # Check exit condition
-        if !yaml.key?('inherit')
+        if file_queue.empty?
           return yaml
         end
 
-        inherit_file = File.expand_path(yaml['inherit'], File.dirname(yamlfile))
-
-        # Check loop
-        if loaded_files[inherit_file]
-          raise "Found circular YAML inheritance '#{inherit_file}' in #{yamlfile}."
+        current_file = file_queue.shift
+        current_yaml = YAML.load_file(current_file)
+        yaml = current_yaml.deep_merge(yaml)
+
+        if yaml.key?('inherit')
+          buf = []
+          yaml['inherit'].reverse_each do |item|
+            inherit_file = File.expand_path(item, File.dirname(yamlfile))
+
+            # Check loop
+            if loaded_files[inherit_file]
+              raise "Found circular YAML inheritance '#{inherit_file}' in #{yamlfile}."
+            end
+
+            loaded_files[inherit_file] = true
+            buf << inherit_file
+          end
+          yaml.delete('inherit')
+          file_queue = buf + file_queue
         end
-
-        loaded_files[inherit_file] = true
-        yaml.delete('inherit')
-        current_file = inherit_file
       end
     end
   end

test/test_yamlloader.rb

@@ -33,7 +33,7 @@ def test_load_file_inherit
 k1:
   name: "test"
   array: [{name: "N", val: "V"}]
-inherit: "test2.yml"
+inherit: ["test2.yml"]
 EOB
       end
       File.open(yaml_file2, "w") do |f|
@@ -53,4 +53,134 @@ def test_load_file_inherit
                    yaml)
     end
   end
+
+  def test_load_file_inherit2
+    Dir.mktmpdir do |dir|
+      yaml_file = File.join(dir, "test.yml")
+      yaml_file2 = File.join(dir, "test2.yml")
+      yaml_file3 = File.join(dir, "test3.yml")
+      File.open(yaml_file, "w") do |f|
+        f.write <<EOB
+k0: 2
+k1:
+  name1: "value1-1"
+inherit: ["test3.yml", "test2.yml"]
+EOB
+      end
+      File.open(yaml_file2, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "value1-2"
+  name2: "value2-2"
+k2: "B"
+EOB
+      end
+      File.open(yaml_file3, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "value1-3"
+  name2: "value2-3"
+  name3: "value3-3"
+k3: "C"
+EOB
+      end
+      yaml = @loader.load_file(yaml_file)
+      assert_equal({"k0" => 2,
+                    "k1" => {"name1"=>"value1-1", "name2"=>"value2-2", "name3"=>"value3-3"},
+                    "k2" => "B",
+                    "k3" => "C",
+                   },
+                   yaml)
+    end
+  end
+
+  def test_load_file_inherit3
+    Dir.mktmpdir do |dir|
+      yaml_file1 = File.join(dir, "test1.yml")
+      yaml_file2 = File.join(dir, "test2.yml")
+      yaml_file3 = File.join(dir, "test3.yml")
+      yaml_file4 = File.join(dir, "test4.yml")
+      yaml_file5 = File.join(dir, "test5.yml")
+      yaml_file6 = File.join(dir, "test6.yml")
+      yaml_file7 = File.join(dir, "test7.yml")
+      File.open(yaml_file7, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N7"
+inherit: ["test3.yml", "test6.yml"]
+EOB
+      end
+      File.open(yaml_file6, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N6"
+  name2: "N6"
+inherit: ["test4.yml", "test5.yml"]
+EOB
+      end
+      File.open(yaml_file5, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N5"
+  name2: "N5"
+  name3: "N5"
+EOB
+      end
+      File.open(yaml_file4, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N4"
+  name2: "N4"
+  name3: "N4"
+  name4: "N4"
+EOB
+      end
+      File.open(yaml_file3, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N3"
+  name2: "N3"
+  name3: "N3"
+  name4: "N3"
+  name5: "N3"
+inherit: ["test1.yml", "test2.yml"]
+EOB
+      end
+      File.open(yaml_file2, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N2"
+  name2: "N2"
+  name3: "N2"
+  name4: "N2"
+  name5: "N2"
+  name6: "N2"
+EOB
+      end
+      File.open(yaml_file1, "w") do |f|
+        f.write <<EOB
+k1:
+  name1: "N1"
+  name2: "N1"
+  name3: "N1"
+  name4: "N1"
+  name5: "N1"
+  name6: "N1"
+  name7: "N1"
+EOB
+      end
+
+      yaml = @loader.load_file(yaml_file7)
+      assert_equal({"k1" => {"name1"=>"N7",
+                             "name2"=>"N6",
+                             "name3"=>"N5",
+                             "name4"=>"N4",
+                             "name5"=>"N3",
+                             "name6"=>"N2",
+                             "name7"=>"N1",
+                            },
+                   },
+                   yaml)
+    end
+  end
 end