Added properties round trip test

acceptance_tests/basic.sh

@@ -1,8 +1,8 @@
 #!/bin/bash
 
 setUp() {
-  rm test*.yml || true
-  rm .xyz -f || true
+  rm test*.yml 2>/dev/null || true
+  rm .xyz 2>/dev/null || true
 }
 
 testBasicEvalRoundTrip() {

acceptance_tests/inputs-format.sh

@@ -1,7 +1,26 @@
 #!/bin/bash
 
 setUp() {
-  rm test*.yml || true
+  rm test*.yml 2>/dev/null || true
+  rm test*.properties 2>/dev/null || true
+  rm test*.xml 2>/dev/null || true
+}
+
+testInputProperties() {
+  cat >test.properties <<EOL
+mike.things = hello
+EOL
+
+  read -r -d '' expected << EOM
+mike:
+  things: hello
+EOM
+
+  X=$(./yq e -p=props test.properties)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=props test.properties)
+  assertEquals "$expected" "$X"
 }
 
 testInputXml() {

cmd/root.go

@@ -63,7 +63,7 @@ yq -i '.stuff = "foo"' myfile.yml # update myfile.yml inplace
 	}
 
 	rootCmd.PersistentFlags().StringVarP(&outputFormat, "output-format", "o", "yaml", "[yaml|y|json|j|props|p|xml|x] output format type.")
-	rootCmd.PersistentFlags().StringVarP(&inputFormat, "input-format", "p", "yaml", "[yaml|y|xml|x] parse format for input. Note that json is a subset of yaml.")
+	rootCmd.PersistentFlags().StringVarP(&inputFormat, "input-format", "p", "yaml", "[yaml|y|props|p|xml|x] parse format for input. Note that json is a subset of yaml.")
 
 	rootCmd.PersistentFlags().StringVar(&xmlAttributePrefix, "xml-attribute-prefix", "+", "prefix for xml attributes")
 	rootCmd.PersistentFlags().StringVar(&xmlContentName, "xml-content-name", "+content", "name for xml content (if no attribute name is present).")

pkg/yqlib/decoder_properties.go

@@ -39,6 +39,13 @@ func parsePropKey(key string) []interface{} {
 	return path
 }
 
+func (dec *propertiesDecoder) processComment(c string) string {
+	if c == "" {
+		return ""
+	}
+	return "# " + c
+}
+
 func (dec *propertiesDecoder) applyProperty(properties *properties.Properties, context Context, key string) error {
 	value, _ := properties.Get(key)
 	path := parsePropKey(key)
@@ -47,7 +54,7 @@ func (dec *propertiesDecoder) applyProperty(properties *properties.Properties, c
 		Value:       value,
 		Tag:         "!!str",
 		Kind:        yaml.ScalarNode,
-		LineComment: properties.GetComment(key),
+		LineComment: dec.processComment(properties.GetComment(key)),
 	}
 
 	rhsNode.Tag = guessTagFromCustomType(rhsNode)

pkg/yqlib/doc/usage/properties.md

@@ -119,3 +119,28 @@ person:
         - pizza
 ```
 
+## Roundtrip
+Given a sample.properties file of:
+```properties
+# comments on values appear
+person.name = Mike
+
+# comments on array values appear
+person.pets.0 = cat
+person.food.0 = pizza
+
+```
+then
+```bash
+yq -p=props -o=props '.person.pets.0 = "dog"' sample.properties
+```
+will output
+```properties
+# comments on values appear
+person.name = Mike
+
+# comments on array values appear
+person.pets.0 = dog
+person.food.0 = pizza
+```
+

pkg/yqlib/properties_test.go

@@ -26,6 +26,14 @@ person.pets.0 = cat
 person.food.0 = pizza
 `
 
+var expectedUpdatedProperties = `# comments on values appear
+person.name = Mike
+
+# comments on array values appear
+person.pets.0 = dog
+person.food.0 = pizza
+`
+
 var expectedDecodedYaml = `person:
   name: Mike # comments on values appear
   pets:
@@ -70,12 +78,18 @@ var propertyScenarios = []formatScenario{
 		expected:       expectedPropertiesWithEmptyMapsAndArrays,
 	},
 	{
-		skipDoc:      true,
 		description:  "Decode properties",
 		input:        expectedProperties,
 		expected:     expectedDecodedYaml,
 		scenarioType: "decode",
 	},
+	{
+		description:  "Roundtrip",
+		input:        expectedProperties,
+		expression:   `.person.pets.0 = "dog"`,
+		expected:     expectedUpdatedProperties,
+		scenarioType: "roundtrip",
+	},
 }
 
 func documentEncodePropertyScenario(w *bufio.Writer, s formatScenario) {
@@ -128,10 +142,37 @@ func documentDecodePropertyScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", processFormatScenario(s, NewYamlEncoder(s.indent, false, true, true), NewPropertiesDecoder())))
 }
 
+func documentRoundTripPropertyScenario(w *bufio.Writer, s formatScenario) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, "Given a sample.properties file of:\n")
+	writeOrPanic(w, fmt.Sprintf("```properties\n%v\n```\n", s.input))
+
+	writeOrPanic(w, "then\n")
+
+	expression := s.expression
+	if expression != "" {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -p=props -o=props '%v' sample.properties\n```\n", expression))
+	} else {
+		writeOrPanic(w, "```bash\nyq -p=props -o=props sample.properties\n```\n")
+	}
+
+	writeOrPanic(w, "will output\n")
+
+	writeOrPanic(w, fmt.Sprintf("```properties\n%v```\n\n", processFormatScenario(s, NewPropertiesEncoder(), NewPropertiesDecoder())))
+}
+
 func documentPropertyScenario(t *testing.T, w *bufio.Writer, i interface{}) {
 	s := i.(formatScenario)
 	if s.scenarioType == "decode" {
 		documentDecodePropertyScenario(w, s)
+	} else if s.scenarioType == "roundtrip" {
+		documentRoundTripPropertyScenario(w, s)
 	} else {
 		documentEncodePropertyScenario(w, s)
 	}
@@ -142,6 +183,8 @@ func TestPropertyScenarios(t *testing.T) {
 	for _, s := range propertyScenarios {
 		if s.scenarioType == "decode" {
 			test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewYamlEncoder(2, false, true, true), NewPropertiesDecoder()), s.description)
+		} else if s.scenarioType == "roundtrip" {
+			test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewPropertiesEncoder(), NewPropertiesDecoder()), s.description)
 		} else {
 			test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewPropertiesEncoder(), NewYamlDecoder()), s.description)
 		}