feat(api): collapse equivalent OpenAPI servers

Normalise server metadata so trailing-slash variants deduplicate to a single entry.

Adds a regression test covering both absolute and relative server URLs.

Co-Authored-By: Virgil <virgil@lethean.io>

openapi_test.go

@@ -1252,3 +1252,43 @@ func TestSpecBuilder_Good_Servers(t *testing.T) {
 		t.Fatalf("expected second server url=%q, got %v", "/", second["url"])
 	}
 }
+
+func TestSpecBuilder_Good_ServersCollapseTrailingSlashes(t *testing.T) {
+	sb := &api.SpecBuilder{
+		Title:   "Test",
+		Version: "1.0.0",
+		Servers: []string{
+			"https://api.example.com/",
+			"https://api.example.com",
+			"/api/",
+			"/api",
+		},
+	}
+
+	data, err := sb.Build(nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	var spec map[string]any
+	if err := json.Unmarshal(data, &spec); err != nil {
+		t.Fatalf("invalid JSON: %v", err)
+	}
+
+	servers, ok := spec["servers"].([]any)
+	if !ok {
+		t.Fatalf("expected servers array, got %T", spec["servers"])
+	}
+	if len(servers) != 2 {
+		t.Fatalf("expected 2 collapsed servers, got %d", len(servers))
+	}
+
+	first := servers[0].(map[string]any)
+	if first["url"] != "https://api.example.com" {
+		t.Fatalf("expected first server url=%q, got %v", "https://api.example.com", first["url"])
+	}
+	second := servers[1].(map[string]any)
+	if second["url"] != "/api" {
+		t.Fatalf("expected second server url=%q, got %v", "/api", second["url"])
+	}
+}

servers.go

@@ -15,7 +15,7 @@ func normaliseServers(servers []string) []string {
 	seen := make(map[string]struct{}, len(servers))
 
 	for _, server := range servers {
-		server = strings.TrimSpace(server)
+		server = normaliseServer(server)
 		if server == "" {
 			continue
 		}
@@ -32,3 +32,22 @@ func normaliseServers(servers []string) []string {
 
 	return cleaned
 }
+
+// normaliseServer trims surrounding whitespace and removes a trailing slash
+// from non-root server URLs so equivalent metadata collapses to one entry.
+func normaliseServer(server string) string {
+	server = strings.TrimSpace(server)
+	if server == "" {
+		return ""
+	}
+	if server == "/" {
+		return server
+	}
+
+	server = strings.TrimRight(server, "/")
+	if server == "" {
+		return "/"
+	}
+
+	return server
+}