test: add validation for 'strict bind on' in BGP rendering tests. Enhance BGP test cases to ensure 'strict bind on' is included in the rendered output, improving test coverage for BGP template configurations.

internal/birdfmt/bgp.go

@@ -73,7 +73,8 @@ type BGPPeerFromTemplateOptions struct {
 	OverrideLocalASN uint32
 }
 
-// RenderProtocolBGPFromTemplate renders protocol bgp … from TEMPLATE { neighbor; multihop; source address; passive; }.
+// RenderProtocolBGPFromTemplate renders protocol bgp … from TEMPLATE { neighbor; multihop; source address; strict bind; passive; }.
+// strict bind дублируется и в шаблоне, и в каждом пире — явная фиксация на сессию.
 func RenderProtocolBGPFromTemplate(opts BGPPeerFromTemplateOptions) (string, error) {
 	if strings.TrimSpace(opts.ProtocolName) == "" {
 		return "", fmt.Errorf("birdfmt: protocol name is required")
@@ -109,6 +110,7 @@ func RenderProtocolBGPFromTemplate(opts BGPPeerFromTemplateOptions) (string, err
 	b.WriteString("    source address ")
 	b.WriteString(strings.TrimSpace(opts.SourceAddress))
 	b.WriteString(";\n")
+	b.WriteString("    strict bind on;\n")
 	b.WriteString("    passive;\n")
 	b.WriteString("}\n")
 	return b.String(), nil

internal/birdfmt/bgp_test.go

@@ -55,6 +55,9 @@ func TestRenderProtocolBGPFromTemplate_MultihopPassive(t *testing.T) {
 	if !strings.Contains(got, "source address 77.232.38.173;") {
 		t.Fatal(got)
 	}
+	if !strings.Contains(got, "strict bind on;") {
+		t.Fatal(got)
+	}
 }
 
 func TestRenderProtocolBGPFromTemplate_OverrideLocal(t *testing.T) {

internal/birdfmt/testdata/scenarios/standard_layout/bird.d/evobgp_peers.conf

@@ -2,5 +2,6 @@ protocol bgp evobgp_peer_ci from bgp_template {
     neighbor 192.0.2.2 as 65002;
     multihop;
     source address 192.0.2.1;
+    strict bind on;
     passive;
 }