internal/testutil: Describe no longer panics on private struct fields

internal/testutil/testutil.go

@@ -2,8 +2,9 @@ package testutil
 
 import "fmt"
 import "slices"
-import "strings"
 import "reflect"
+import "strings"
+import "unicode"
 
 // Snake lets you compare blocks of data where the ordering of certain parts may
 // be swapped every which way. It is designed for comparing the encoding of
@@ -141,8 +142,16 @@ func (this *describer) describe(value reflect.Value) {
 		typ := value.Type()
 		for index := range typ.NumField() {
 			indexBuffer := [1]int { index }
-			this.iprintf("%s: ", typ.Field(index).Name)
-			this.describe(value.FieldByIndex(indexBuffer[:]))
+			field := typ.Field(index)
+			this.iprintf("%s: ", field.Name)
+			for _, char := range field.Name {
+				if unicode.IsUpper(char) {
+					this.describe(value.FieldByIndex(indexBuffer[:]))
+				} else {
+					this.printf("<private>")
+				}
+				break
+			}
 			this.iprintf("\n")
 		}
 		this.indent -= 1