fix(common-openapi): resolve full servers[] precedence in OpenapiOperationView

runtime/common-openapi/src/main/java/io/aklivity/zilla/runtime/common/openapi/view/OpenapiOperationView.java

@@ -20,9 +20,11 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import io.aklivity.zilla.runtime.common.openapi.config.OpenapiServerConfig;
 import io.aklivity.zilla.runtime.common.openapi.model.OpenapiOperation;
+import io.aklivity.zilla.runtime.common.openapi.model.OpenapiServer;
 import io.aklivity.zilla.runtime.common.openapi.model.resolver.OpenapiResolver;
 
 public final class OpenapiOperationView
@@ -50,6 +52,7 @@ public final class OpenapiOperationView
         OpenapiResolver resolver,
         String method,
         String path,
+        List<OpenapiServer> pathServers,
         OpenapiOperation model)
     {
         this.specification = specification;
@@ -83,9 +86,13 @@ public final class OpenapiOperationView
                     .toList()
                 : specification.security;
 
-        this.servers = model.servers != null
-                ? model.servers.stream()
-                    .flatMap(s -> configs.stream().map(c -> new OpenapiServerView(resolver, s, c)))
+        List<OpenapiServer> effectiveServers = model.servers != null ? model.servers : pathServers;
+
+        this.servers = effectiveServers != null
+                ? effectiveServers.stream()
+                    .flatMap(s -> configs.isEmpty()
+                        ? Stream.of(new OpenapiServerView(resolver, s, null))
+                        : configs.stream().map(c -> new OpenapiServerView(resolver, s, c)))
                     .toList()
                 : specification.servers;
 

runtime/common-openapi/src/main/java/io/aklivity/zilla/runtime/common/openapi/view/OpenapiPathView.java

@@ -80,7 +80,7 @@ public final class OpenapiPathView
             .filter(e -> e.getValue().apply(model) != null)
             .collect(Collectors.toMap(Map.Entry::getKey, e ->
                 new OpenapiOperationView(specification, supplyCompositeId.getAsLong(),
-                        configs, resolver, e.getKey(), path, e.getValue().apply(model))));
+                        configs, resolver, e.getKey(), path, model.servers, e.getValue().apply(model))));
         this.extensions = model.extensions;
     }
 

runtime/common-openapi/src/test/java/io/aklivity/zilla/runtime/common/openapi/view/OpenapiViewTest.java

@@ -39,6 +39,7 @@
 import io.aklivity.zilla.runtime.common.openapi.model.OpenapiSchema;
 import io.aklivity.zilla.runtime.common.openapi.model.OpenapiSecurityScheme;
 import io.aklivity.zilla.runtime.common.openapi.model.OpenapiServer;
+import io.aklivity.zilla.runtime.common.openapi.model.OpenapiServerVariable;
 
 public class OpenapiViewTest
 {
@@ -305,6 +306,154 @@ public void shouldNotResolveScopesWithoutFlows() throws Exception
         assertEquals(List.of(), schemeView.scopes);
     }
 
+    @Test
+    public void shouldResolveOperationLevelServersOverPathAndRoot() throws Exception
+    {
+        OpenapiServer rootServer = new OpenapiServer();
+        rootServer.url = "http://root.example.com";
+
+        OpenapiServer pathServer = new OpenapiServer();
+        pathServer.url = "http://path.example.com";
+
+        OpenapiServer operationServer = new OpenapiServer();
+        operationServer.url = "http://operation.example.com";
+
+        OpenapiOperation operation = new OpenapiOperation();
+        operation.operationId = "ReadItems";
+        operation.servers = List.of(operationServer);
+
+        OpenapiPath path = new OpenapiPath();
+        path.get = operation;
+        path.servers = List.of(pathServer);
+
+        Openapi model = new Openapi();
+        model.servers = List.of(rootServer);
+        model.paths = Map.of("/items", path);
+
+        OpenapiServerConfig config = OpenapiServerConfig.builder().build();
+        OpenapiView view = OpenapiView.of(model, List.of(config));
+        OpenapiOperationView operationView = view.paths.get("/items").methods.get("GET");
+
+        assertEquals(1, operationView.servers.size());
+        assertEquals(URI.create("http://operation.example.com:80"), operationView.servers.get(0).url);
+    }
+
+    @Test
+    public void shouldResolvePathLevelServersOverRootWhenOperationHasNone() throws Exception
+    {
+        OpenapiServer rootServer = new OpenapiServer();
+        rootServer.url = "http://root.example.com";
+
+        OpenapiServer pathServer = new OpenapiServer();
+        pathServer.url = "http://path.example.com";
+
+        OpenapiOperation operation = new OpenapiOperation();
+        operation.operationId = "ReadItems";
+
+        OpenapiPath path = new OpenapiPath();
+        path.get = operation;
+        path.servers = List.of(pathServer);
+
+        Openapi model = new Openapi();
+        model.servers = List.of(rootServer);
+        model.paths = Map.of("/items", path);
+
+        OpenapiServerConfig config = OpenapiServerConfig.builder().build();
+        OpenapiView view = OpenapiView.of(model, List.of(config));
+        OpenapiOperationView operationView = view.paths.get("/items").methods.get("GET");
+
+        assertEquals(1, operationView.servers.size());
+        assertEquals(URI.create("http://path.example.com:80"), operationView.servers.get(0).url);
+    }
+
+    @Test
+    public void shouldResolveRootLevelServersWhenNoOperationOrPathServers() throws Exception
+    {
+        OpenapiServer rootServer = new OpenapiServer();
+        rootServer.url = "http://root.example.com";
+
+        OpenapiOperation operation = new OpenapiOperation();
+        operation.operationId = "ReadItems";
+
+        OpenapiPath path = new OpenapiPath();
+        path.get = operation;
+
+        Openapi model = new Openapi();
+        model.servers = List.of(rootServer);
+        model.paths = Map.of("/items", path);
+
+        OpenapiServerConfig config = OpenapiServerConfig.builder().build();
+        OpenapiView view = OpenapiView.of(model, List.of(config));
+        OpenapiOperationView operationView = view.paths.get("/items").methods.get("GET");
+
+        assertEquals(1, operationView.servers.size());
+        assertEquals(URI.create("http://root.example.com:80"), operationView.servers.get(0).url);
+    }
+
+    @Test
+    public void shouldResolveServerUrlVariableDefaultWhenNoOverride() throws Exception
+    {
+        OpenapiServerVariable variable = new OpenapiServerVariable();
+        variable.values = List.of("prod", "staging");
+        variable.defaultValue = "prod";
+
+        OpenapiServer server = new OpenapiServer();
+        server.url = "http://{env}.example.com";
+        server.variables = Map.of("env", variable);
+
+        Openapi model = new Openapi();
+        model.servers = List.of(server);
+
+        OpenapiServerConfig config = OpenapiServerConfig.builder().build();
+        OpenapiView view = OpenapiView.of(model, List.of(config));
+
+        assertEquals(URI.create("http://prod.example.com:80"), view.servers.get(0).url);
+    }
+
+    @Test
+    public void shouldResolveServerUrlVariableOverrideMatchingPattern() throws Exception
+    {
+        OpenapiServerVariable variable = new OpenapiServerVariable();
+        variable.values = List.of("prod", "staging");
+        variable.defaultValue = "prod";
+
+        OpenapiServer server = new OpenapiServer();
+        server.url = "http://{env}.example.com";
+        server.variables = Map.of("env", variable);
+
+        Openapi model = new Openapi();
+        model.servers = List.of(server);
+
+        OpenapiServerConfig config = OpenapiServerConfig.builder()
+            .url("http://staging.example.com")
+            .build();
+        OpenapiView view = OpenapiView.of(model, List.of(config));
+
+        assertEquals(URI.create("http://staging.example.com:80"), view.servers.get(0).url);
+    }
+
+    @Test
+    public void shouldDefaultServerUrlVariableWhenOverrideDoesNotMatchPattern() throws Exception
+    {
+        OpenapiServerVariable variable = new OpenapiServerVariable();
+        variable.values = List.of("prod", "staging");
+        variable.defaultValue = "prod";
+
+        OpenapiServer server = new OpenapiServer();
+        server.url = "http://{env}.example.com";
+        server.variables = Map.of("env", variable);
+
+        Openapi model = new Openapi();
+        model.servers = List.of(server);
+
+        OpenapiServerConfig config = OpenapiServerConfig.builder()
+            .url("http://dev.example.com")
+            .build();
+        OpenapiView view = OpenapiView.of(model, List.of(config));
+
+        assertEquals(URI.create("http://prod.example.com:80"), view.servers.get(0).url);
+    }
+
     public static final class SampleExtension
     {
         public String key;