Update TruncateDescription

- Implement word boundary handling
- Add ellipsis

Signed-off-by: Dale Haiducek <[email protected]>

pkg/crd/desc_visitor.go

@@ -33,7 +33,7 @@ func TruncateDescription(schema *apiext.JSONSchemaProps, maxLen int) {
 // descVisitor recursively visits all fields in the schema and truncates the
 // description of the fields to specified maxLen.
 type descVisitor struct {
-	// maxLen is the maximum allowed length for decription of a field
+	// maxLen is the maximum allowed length for description of a field
 	maxLen int
 }
 
@@ -60,19 +60,31 @@ func (v descVisitor) Visit(schema *apiext.JSONSchemaProps) SchemaVisitor {
 // exceeds maxLen because it tries to chop off the desc at the closest sentence
 // boundary to avoid incomplete sentences.
 func truncateString(desc string, maxLen int) string {
+	if len(desc) <= maxLen {
+		return desc
+	}
+
 	desc = desc[0:maxLen]
 
 	// Trying to chop off at closest sentence boundary.
 	if n := strings.LastIndexFunc(desc, isSentenceTerminal); n > 0 {
 		return desc[0 : n+1]
 	}
-	// TODO(droot): Improve the logic to chop off at closest word boundary
-	// or add elipses (...) to indicate that it's chopped incase no closest
-	// sentence found within maxLen.
-	return desc
+
+	// Trying to chop off at closest word boundary (i.e. whitespace).
+	if n := strings.LastIndexFunc(desc, isWhiteSpace); n > 0 {
+		return desc[0 : n] + "..."
+	}
+
+	return desc[0:maxLen] + "..."
 }
 
 // helper function to determine if given rune is a sentence terminal or not.
 func isSentenceTerminal(r rune) bool {
 	return unicode.Is(unicode.STerm, r)
 }
+
+// helper function to determine if given rune is whitespace or not.
+func isWhiteSpace(r rune) bool {
+	return unicode.Is(unicode.White_Space, r)
+}

pkg/crd/desc_visitor_test.go

@@ -75,7 +75,7 @@ var _ = Describe("TruncateDescription", func() {
 		}
 		crd.TruncateDescription(schema, len(schema.Description)-2)
 		Expect(schema).To(Equal(&apiext.JSONSchemaProps{
-			Description: `This is top level description of the root obje`,
+			Description: `This is top level description of the root...`,
 		}))
 	})
 })

pkg/crd/gen.go

@@ -93,7 +93,7 @@ type Generator struct {
 	// This value can only be specified for CustomResourceDefinitions that were created with
 	// `apiextensions.k8s.io/v1beta1`.
 	//
-	// The field can be set for compatiblity reasons, although strongly discouraged, resource
+	// The field can be set for compatibility reasons, although strongly discouraged, resource
 	// authors should move to a structural OpenAPI schema instead.
 	//
 	// See https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#field-pruning