Add WebSocket support and launcher

Author: haydenbaker

README.md

@@ -4,6 +4,36 @@
 A [Language Server Protocol](https://microsoft.github.io/language-server-protocol/)
 implementation for the [Smithy IDL](https://awslabs.github.io/smithy/).
 
+
+### Running the LSP
+
+There are three ways to launch the LSP, and which you choose depends on your use case.
+
+In all cases, the communication protocol is JSON-RPC, the transport channels can are:
+
+#### Stdio
+
+Run `./gradlew run --args="0"`
+
+The LSP will use stdio (stdin, stdout) to communicate.
+
+#### Sockets
+
+Run `./gradlew run --args="12423"`
+
+The LSP will try to connect to the given port using a TCP socket - if it can't, it will fail.
+
+This is used by the VSCode extension to establish a connection between it and the LSP (which is launched
+as a local process)
+
+#### WebSockets
+
+Run `./gradlew run --args="3000 --ws"`
+
+The LSP will start a WebSocket server, which listens on given port.
+
+This can be used to connect to a remote server running the LSP (more specifically from, but not limited to, the browser).  
+
 ## Security
 
 See [CONTRIBUTING](CONTRIBUTING.md#security-issue-notifications) for more information.

build.gradle

@@ -157,6 +157,10 @@ publishing {
 
 dependencies {
     implementation "org.eclipse.lsp4j:org.eclipse.lsp4j:0.14.0"
+    implementation 'org.eclipse.lsp4j:org.eclipse.lsp4j.websocket:0.14.0'
+    implementation 'org.eclipse.lsp4j:org.eclipse.lsp4j.websocket.jakarta:0.14.0'
+    implementation 'org.glassfish.tyrus:tyrus-server:2.0.1'
+    implementation 'org.glassfish.tyrus:tyrus-container-grizzly-server:2.0.1'
     implementation "software.amazon.smithy:smithy-model:[1.31.0, 2.0["
     implementation 'io.get-coursier:interface:1.0.4'
     implementation 'com.disneystreaming.smithy:smithytranslate-formatter-jvm-java-api:0.3.4'
@@ -218,6 +222,10 @@ jar {
         exclude "META-INF/*.DSA"
         exclude "META-INF/*.RSA"
         exclude "reflect.properties"
+        exclude "META-INF/LICENSE.md"
+        exclude "META-INF/LICENSE.txt"
+        exclude "META-INF/NOTICE.md"
+        exclude "module-info.class"
     }
     manifest {
         attributes("Main-Class": "software.amazon.smithy.lsp.Main")

src/main/java/software/amazon/smithy/lsp/Main.java

@@ -18,10 +18,14 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.Socket;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
 import java.util.Optional;
 import org.eclipse.lsp4j.jsonrpc.Launcher;
 import org.eclipse.lsp4j.launch.LSPLauncher;
 import org.eclipse.lsp4j.services.LanguageClient;
+import software.amazon.smithy.lsp.websocket.WebSocketRunner;
 
 /**
  * Main launcher for the Language server, started by the editor.
@@ -61,9 +65,21 @@ public static void main(String[] args) {
         Socket socket = null;
         InputStream in;
         OutputStream out;
-
+        List<String> argList = Arrays.asList(args);
         try {
-            String port = args[0];
+            Optional<Exception> launchFailure;
+            String port = getOrDefault(argList, 0, "0");
+            String type = getOrDefault(argList, 1, null);
+
+            // Check if websocket option is present
+            if ("--ws".equals(type)) {
+                WebSocketRunner webSocketRunner = new WebSocketRunner();
+                String hostname = "localhost";
+                String contextPath = "/";
+                webSocketRunner.run(hostname, Integer.parseInt(port), contextPath);
+                return;
+            }
+
             // If port is set to "0", use System.in/System.out.
             if (port.equals("0")) {
                 in = System.in;
@@ -73,9 +89,7 @@ public static void main(String[] args) {
                 in = socket.getInputStream();
                 out = socket.getOutputStream();
             }
-
-            Optional<Exception> launchFailure = launch(in, out);
-
+            launchFailure = launch(in, out);
             if (launchFailure.isPresent()) {
                 throw launchFailure.get();
             } else {
@@ -86,7 +100,7 @@ public static void main(String[] args) {
         } catch (NumberFormatException e) {
             System.out.println("Port number must be a valid integer");
         } catch (Exception e) {
-            System.out.println(e);
+            System.out.println("Failed to start: " + e);
 
             e.printStackTrace();
         } finally {
@@ -95,9 +109,22 @@ public static void main(String[] args) {
                     socket.close();
                 }
             } catch (Exception e) {
-                System.out.println("Failed to close the socket");
-                System.out.println(e);
+                System.out.println("Failed to close the socket: " + e);
             }
         }
     }
+
+    private static boolean isEmpty(Collection<?> c) {
+        return c == null || c.isEmpty();
+    }
+
+    private static <T> T getOrDefault(List<T> list, int index, T t) {
+        if (isEmpty(list)) {
+            return t;
+        }
+        if (index < 0 || index >= list.size()) {
+            return t;
+        }
+        return list.get(index);
+    }
 }

src/main/java/software/amazon/smithy/lsp/websocket/SmithyWebSocketEndpoint.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.lsp.websocket;
+
+import java.util.Collection;
+import org.eclipse.lsp4j.jsonrpc.Launcher.Builder;
+import org.eclipse.lsp4j.services.LanguageClient;
+import org.eclipse.lsp4j.services.LanguageClientAware;
+import org.eclipse.lsp4j.websocket.jakarta.WebSocketEndpoint;
+import software.amazon.smithy.lsp.SmithyLanguageServer;
+
+public class SmithyWebSocketEndpoint extends WebSocketEndpoint<LanguageClient> {
+
+    @Override
+    protected void configure(Builder<LanguageClient> builder) {
+        builder.setLocalService(new SmithyLanguageServer());
+        builder.setRemoteInterface(LanguageClient.class);
+    }
+
+    @Override
+    protected void connect(Collection<Object> localServices, LanguageClient remoteProxy) {
+        localServices.stream()
+                .filter(LanguageClientAware.class::isInstance)
+                .forEach(languageClientAware -> ((LanguageClientAware) languageClientAware).connect(remoteProxy));
+    }
+
+}

src/main/java/software/amazon/smithy/lsp/websocket/SmithyWebSocketServerConfigProvider.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.lsp.websocket;
+
+import jakarta.websocket.Endpoint;
+import jakarta.websocket.server.ServerApplicationConfig;
+import jakarta.websocket.server.ServerEndpointConfig;
+import java.util.Collections;
+import java.util.Set;
+
+public class SmithyWebSocketServerConfigProvider implements ServerApplicationConfig {
+
+    private static final String LSP_PATH = "/";
+
+    @Override
+    public Set<ServerEndpointConfig> getEndpointConfigs(Set<Class<? extends Endpoint>> endpointClasses) {
+        ServerEndpointConfig conf =
+                ServerEndpointConfig.Builder.create(SmithyWebSocketEndpoint.class,
+                        LSP_PATH).build();
+        return Collections.singleton(conf);
+    }
+
+    @Override
+    public Set<Class<?>> getAnnotatedEndpointClasses(Set<Class<?>> scanned) {
+        return scanned;
+    }
+
+}

src/main/java/software/amazon/smithy/lsp/websocket/WebSocketRunner.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.lsp.websocket;
+
+import jakarta.websocket.DeploymentException;
+import org.glassfish.tyrus.server.Server;
+import software.amazon.smithy.lsp.ext.LspLog;
+
+public class WebSocketRunner {
+    private static final String DEFAULT_HOSTNAME = "localhost";
+    private static final int DEFAULT_PORT = 3000;
+    private static final String DEFAULT_CONTEXT_PATH = "/";
+
+    /**
+     * Run the websocket server on port of given host and path.
+     * @param hostname hostname for server
+     * @param port port server will listen on
+     * @param contextPath path which routes to the lsp
+     */
+    public void run(String hostname, int port, String contextPath) {
+        Server server = new Server(
+                hostname != null ? hostname : DEFAULT_HOSTNAME,
+                port > 0 ? port : DEFAULT_PORT,
+                contextPath != null ? contextPath : DEFAULT_CONTEXT_PATH,
+                null,
+                SmithyWebSocketServerConfigProvider.class
+        );
+        Runtime.getRuntime().addShutdownHook(new Thread(server::stop, "smithy-lsp-websocket-server-shutdown-hook"));
+
+        try {
+            server.start();
+            Thread.currentThread().join();
+        } catch (InterruptedException e) {
+            LspLog.println("Smithy LSP Websocket server has been interrupted.");
+            Thread.currentThread().interrupt();
+        } catch (DeploymentException e) {
+            LspLog.println("Could not start Smithy LSP Websocket server.");
+        } finally {
+            server.stop();
+        }
+    }
+}