add message diff for doc linter (#25814)

internal/tools/document-lint/check/check_iface.go

@@ -62,3 +62,29 @@ func newCheckBase(line int, key string, mdField *model.Field) checkBase {
 		mdField: mdField,
 	}
 }
+
+// for some special diff, we need to show message instead of diff
+type diffWithMessage struct {
+	checkBase
+	msg  string
+	skip bool
+}
+
+func (i diffWithMessage) Fix(line string) (string, error) {
+	return line, nil
+}
+
+func (i diffWithMessage) String() string {
+	return i.msg
+}
+func (i diffWithMessage) ShouldSkip() bool {
+	return i.skip
+}
+
+func newDiffWithMessage(msg string, skip bool) Checker {
+	return diffWithMessage{
+		checkBase: newCheckBase(0, msg, nil),
+		msg:       msg,
+		skip:      skip,
+	}
+}

internal/tools/document-lint/check/check_resource.go

@@ -75,6 +75,10 @@ func NewResourceDiff(tf *schema.Resource) *ResourceDiff {
 
 func (r *ResourceDiff) DiffAll() {
 	if r.md == nil {
+		if r.MDFile == "" {
+			r.Diff = append(r.Diff, newDiffWithMessage(fmt.Sprintf("%s has no document", r.tf.ResourceType), r.tf.IsDeprecated()))
+			return
+		}
 		mark := md.MustNewMarkFromFile(r.MDFile)
 		r.md = mark.BuildResourceDoc()
 	}

internal/tools/document-lint/check/document_fixer.go

@@ -96,6 +96,10 @@ func (f *Fixer) TryFix() (err error) {
 	if len(f.Diff) == 0 {
 		return
 	}
+	if d, ok := f.Diff[0].(diffWithMessage); ok {
+		log.Printf("%s: %s", f.ResourceType, d.msg)
+		return
+	}
 	content, err := os.ReadFile(f.MDFile)
 	if err != nil {
 		log.Printf("open %s: %v", f.MDFile, err)

internal/tools/document-lint/schema/resource_schema.go

@@ -105,3 +105,13 @@ func (r *Resource) HasPathFor(path []string) bool {
 	}
 	return true
 }
+
+func (r *Resource) IsDeprecated() bool {
+	if r.Schema != nil {
+		return r.Schema.DeprecationMessage != ""
+	} else if _, ok := r.SDKResource.(sdk.ResourceWithDeprecationReplacedBy); ok {
+		return true
+	}
+
+	return false
+}