Add unit test

variables/yaml_helpers.go

@@ -282,9 +282,7 @@ func ParseYamlString(str string) (interface{}, error) {
 		return nil, errors.WithStackTrace(err)
 	}
 
-	parsedValue = Convert(parsedValue)
-
-	return parsedValue, nil
+	return Convert(parsedValue), nil
 }
 
 // Parse a list of YAML files that define variables into a map from variable name to variable value. Along the way,
@@ -344,7 +342,7 @@ func ParseVars(varsList []string, varFileList []string) (map[string]interface{},
 	return util.MergeMaps(varsFromVarsList, varsFromVarFiles), nil
 }
 
-// Convert converts i of type map[interface{}]interface{} to a map[string]interface{} so that it may be properly
+// Convert updates i of type map[interface{}]interface{} to a map[string]interface{} so that it may be properly
 // marshalled in to JSON.
 // See: https://github.com/go-yaml/yaml/issues/139
 func Convert(i interface{}) interface{} {

variables/yaml_helpers_test.go

@@ -76,3 +76,44 @@ func TestParseVariablesFromKeyValuePairs(t *testing.T) {
 		}
 	}
 }
+
+func TestConvert(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		input        interface{}
+		expectedType interface{}
+	}{
+		{
+			input:        "",
+			expectedType: "string",
+		},
+		{
+			input: map[interface{}]interface{}{
+				"key1": "value1",
+				"key2": "value2",
+			},
+			expectedType: map[string]interface{}{},
+		},
+		{
+			input: map[string]interface{}{
+				"key1": "value1",
+			},
+			expectedType: map[string]interface{}{},
+		},
+		{
+			input: []interface{}{
+				map[interface{}]interface{}{
+					"key1": "value1",
+				},
+				"",
+			},
+			expectedType: []interface{}{},
+		},
+	}
+
+	for _, testCase := range testCases {
+		actual := Convert(testCase.input)
+		assert.IsType(t, testCase.expectedType, actual)
+	}
+}