Fix CNAME updates to use content as target host

internal/dynuclient/client.go

@@ -343,7 +343,7 @@ func buildDNSRecordUpsertPayload(recordType string, nodeName string, content *st
 			payload.IPv6Address = *normalizedContent
 		}
 	case "CNAME":
-		if payload.Host == "" && normalizedContent != nil {
+		if normalizedContent != nil {
 			payload.Host = *normalizedContent
 		}
 	default:

internal/dynuclient/client_test.go

@@ -290,6 +290,34 @@ func TestClientCreateDNSRecordSendsHostForCNAMERecord(t *testing.T) {
 	}
 }
 
+func TestClientUpdateDNSRecordCNAMEContentOverridesHost(t *testing.T) {
+	var captured map[string]any
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost || r.URL.Path != "/dns/1001/record/11" {
+			t.Fatalf("unexpected request %s %s", r.Method, r.URL.Path)
+		}
+		if err := json.NewDecoder(r.Body).Decode(&captured); err != nil {
+			t.Fatalf("failed to decode payload: %v", err)
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{"statusCode": 200, "id": 11, "domainId": 1001, "recordType": "CNAME", "host": "example.co"})
+	}))
+	defer server.Close()
+
+	client := dynuclient.New("test-key", dynuclient.WithBaseURL(server.URL), dynuclient.WithHTTPClient(server.Client()))
+	_, err := client.UpdateDNSRecord(context.Background(), 1001, 11, dynuclient.UpdateDNSRecordRequest{
+		NodeName:   "alias",
+		RecordType: "CNAME",
+		Content:    stringPointer("example.co"),
+		Host:       "example.com",
+	})
+	if err != nil {
+		t.Fatalf("UpdateDNSRecord() error = %v", err)
+	}
+	if captured["host"] != "example.co" {
+		t.Fatalf("expected host to be overridden by content, got %#v", captured["host"])
+	}
+}
+
 func TestClientCreateDNSRecordSendsContentForTXTRecord(t *testing.T) {
 	var captured map[string]any
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

internal/provider/resource_dns_record.go

@@ -146,6 +146,7 @@ func (r *dnsRecordResource) Create(ctx context.Context, req resource.CreateReque
 		Group:      stringFromOptional(plan.Group),
 		Host:       stringFromOptional(plan.Host),
 	}
+	createReq = normalizeDNSRecordCreateRequestForType(createReq)
 	if !validateDNSRecordContentForType(createReq.RecordType, createReq.Content, dynamicIntent, &resp.Diagnostics) {
 		return
 	}
@@ -242,6 +243,7 @@ func (r *dnsRecordResource) Update(ctx context.Context, req resource.UpdateReque
 		Group:      stringFromOptional(preferKnownString(plan.Group, state.Group)),
 		Host:       stringFromOptional(preferKnownString(plan.Host, state.Host)),
 	}
+	updateReq = normalizeDNSRecordUpdateRequestForType(updateReq)
 	if !validateDNSRecordContentForType(updateReq.RecordType, updateReq.Content, dynamicIntent, &resp.Diagnostics) {
 		return
 	}
@@ -315,7 +317,7 @@ func (r *dnsRecordResource) ImportState(ctx context.Context, req resource.Import
 }
 
 func mapDNSRecordToState(record dynuclient.DNSRecord, dynamicIntent bool) dnsRecordResourceModel {
-	content := normalizeRecordContentForState(record.RecordType, record.Content, dynamicIntent)
+	content := normalizeRecordContentForState(record.RecordType, record.Content, dynamicIntent, record.Host)
 	return dnsRecordResourceModel{
 		Hostname:   mapString(record.Hostname),
 		RecordType: mapString(record.RecordType),
@@ -442,6 +444,35 @@ func stringPointer(value string) *string {
 	return &value
 }
 
+func normalizeDNSRecordCreateRequestForType(req dynuclient.CreateDNSRecordRequest) dynuclient.CreateDNSRecordRequest {
+	if strings.EqualFold(strings.TrimSpace(req.RecordType), "CNAME") {
+		if normalizedContent := normalizeOptionalContentString(req.Content); normalizedContent != nil {
+			req.Host = *normalizedContent
+		}
+	}
+	return req
+}
+
+func normalizeDNSRecordUpdateRequestForType(req dynuclient.UpdateDNSRecordRequest) dynuclient.UpdateDNSRecordRequest {
+	if strings.EqualFold(strings.TrimSpace(req.RecordType), "CNAME") {
+		if normalizedContent := normalizeOptionalContentString(req.Content); normalizedContent != nil {
+			req.Host = *normalizedContent
+		}
+	}
+	return req
+}
+
+func normalizeOptionalContentString(content *string) *string {
+	if content == nil {
+		return nil
+	}
+	trimmed := strings.TrimSpace(*content)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}
+
 func validateDNSRecordContentForType(recordType string, content *string, dynamicIntent bool, diagnostics *diag.Diagnostics) bool {
 	return validateDNSRecordContentForTypeWithKnowledge(recordType, content, true, dynamicIntent, diagnostics)
 }
@@ -548,7 +579,7 @@ func inferDynamicIntentFromState(recordType types.String, content types.String,
 	return content.IsNull() || (content.IsUnknown())
 }
 
-func normalizeRecordContentForState(recordType string, content string, dynamicIntent bool) types.String {
+func normalizeRecordContentForState(recordType string, content string, dynamicIntent bool, host string) types.String {
 	if dynamicIntent {
 		return types.StringNull()
 	}
@@ -569,6 +600,9 @@ func normalizeRecordContentForState(recordType string, content string, dynamicIn
 			return types.StringValue(addr.String())
 		}
 	case "CNAME":
+		if trimmedHost := strings.TrimSpace(host); trimmedHost != "" {
+			return types.StringValue(strings.TrimSuffix(trimmedHost, "."))
+		}
 		return types.StringValue(strings.TrimSuffix(trimmed, "."))
 	}
 

internal/provider/resource_dns_record_test.go

@@ -146,17 +146,33 @@ func TestStringPointerFromOptionalContentForValidation(t *testing.T) {
 }
 
 func TestNormalizeRecordContentForState(t *testing.T) {
-	if got := normalizeRecordContentForState("AAAA", "2001:0db8:0000:0000:0000:0000:0000:0123", false); got.ValueString() != "2001:db8::123" {
+	if got := normalizeRecordContentForState("AAAA", "2001:0db8:0000:0000:0000:0000:0000:0123", false, ""); got.ValueString() != "2001:db8::123" {
 		t.Fatalf("expected canonical IPv6, got %q", got.ValueString())
 	}
-	if got := normalizeRecordContentForState("CNAME", "Example.COM.", false); got.ValueString() != "Example.COM" {
+	if got := normalizeRecordContentForState("CNAME", "Example.COM.", false, ""); got.ValueString() != "Example.COM" {
 		t.Fatalf("expected trailing dot removed, got %q", got.ValueString())
 	}
-	if got := normalizeRecordContentForState("A", "(167.179.167.166)", true); !got.IsNull() {
+	if got := normalizeRecordContentForState("CNAME", "old.example.com", false, "new.example.co."); got.ValueString() != "new.example.co" {
+		t.Fatalf("expected CNAME content to come from host, got %q", got.ValueString())
+	}
+	if got := normalizeRecordContentForState("A", "(167.179.167.166)", true, ""); !got.IsNull() {
 		t.Fatalf("expected dynamic content to remain null, got %q", got.ValueString())
 	}
 }
 
+func TestNormalizeDNSRecordUpdateRequestForType(t *testing.T) {
+	oldHost := "example.com"
+	newContent := "example.co"
+	req := normalizeDNSRecordUpdateRequestForType(dynuclient.UpdateDNSRecordRequest{
+		RecordType: "CNAME",
+		Content:    &newContent,
+		Host:       oldHost,
+	})
+	if req.Host != "example.co" {
+		t.Fatalf("expected CNAME host to be normalized from content, got %q", req.Host)
+	}
+}
+
 func TestInferDynamicIntentFromState(t *testing.T) {
 	tests := []struct {
 		name       string