Improved property conversion docs

pkg/yqlib/properties_test.go

@@ -0,0 +1,104 @@
+package yqlib
+
+import (
+	"bufio"
+	"fmt"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+var samplePropertiesYaml = `# block comments don't come through
+person: # neither do comments on maps
+    name: Mike # comments on values appear
+    pets: 
+    - cat # comments on array values appear
+    food: [pizza] # comments on arrays do not
+emptyArray: []
+emptyMap: []
+`
+
+var expectedProperties = `# comments on values appear
+person.name = Mike
+
+# comments on array values appear
+person.pets.0 = cat
+person.food.0 = pizza
+`
+
+var expectedPropertiesNoComments = `person.name = Mike
+person.pets.0 = cat
+person.food.0 = pizza
+`
+
+var expectedPropertiesWithEmptyMapsAndArrays = `# comments on values appear
+person.name = Mike
+
+# comments on array values appear
+person.pets.0 = cat
+person.food.0 = pizza
+emptyArray = 
+emptyMap = 
+`
+
+var propertyScenarios = []formatScenario{
+	{
+		description:    "Encode properties",
+		subdescription: "Note that empty arrays and maps are not encoded by default.",
+		input:          samplePropertiesYaml,
+		expected:       expectedProperties,
+	},
+	{
+		description: "Encode properties: no comments",
+		input:       samplePropertiesYaml,
+		expected:    expectedPropertiesNoComments,
+		expression:  `... comments = ""`,
+	},
+	{
+		description:    "Encode properties: include empty maps and arrays",
+		subdescription: "Use a yq expression to set the empty maps and sequences to your desired value.",
+		expression:     `(.. | select( (tag == "!!map" or tag =="!!seq") and length == 0)) = ""`,
+		input:          samplePropertiesYaml,
+		expected:       expectedPropertiesWithEmptyMapsAndArrays,
+	},
+}
+
+func documentPropertyScenario(t *testing.T, w *bufio.Writer, i interface{}) {
+	s := i.(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.yml file of:\n")
+	writeOrPanic(w, fmt.Sprintf("```yaml\n%v\n```\n", s.input))
+
+	writeOrPanic(w, "then\n")
+
+	expression := s.expression
+	if expression == "" {
+		expression = "."
+	}
+
+	if s.indent == 2 {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -o=props '%v' sample.yml\n```\n", expression))
+	} else {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -o=props -I=%v '%v' sample.yml\n```\n", s.indent, expression))
+	}
+	writeOrPanic(w, "will output\n")
+
+	writeOrPanic(w, fmt.Sprintf("```properties\n%v```\n\n", processFormatScenario(s, NewPropertiesEncoder())))
+}
+
+func TestPropertyScenarios(t *testing.T) {
+	for _, s := range propertyScenarios {
+		test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewPropertiesEncoder()), s.description)
+	}
+	genericScenarios := make([]interface{}, len(propertyScenarios))
+	for i, s := range propertyScenarios {
+		genericScenarios[i] = s
+	}
+	documentScenarios(t, "usage", "properties", genericScenarios, documentPropertyScenario)
+}