chore: get rid of connection factory (#362)

Drive-by User-Agent sniffing and disabling of image type in Cursor.

src/connection.ts

@@ -0,0 +1,105 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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.
+ */
+
+import { Server } from '@modelcontextprotocol/sdk/server/index.js';
+import { CallToolRequestSchema, ListToolsRequestSchema, Tool as McpTool } from '@modelcontextprotocol/sdk/types.js';
+import { zodToJsonSchema } from 'zod-to-json-schema';
+
+import { Context } from './context.js';
+import { snapshotTools, screenshotTools } from './tools.js';
+
+import type { Config } from '../config.js';
+import type { Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
+
+import packageJSON from '../package.json' with { type: 'json' };
+
+export async function createConnection(config: Config): Promise<Connection> {
+  const allTools = config.vision ? screenshotTools : snapshotTools;
+  const tools = allTools.filter(tool => !config.capabilities || tool.capability === 'core' || config.capabilities.includes(tool.capability));
+
+  const context = new Context(tools, config);
+  const server = new Server({ name: 'Playwright', version: packageJSON.version }, {
+    capabilities: {
+      tools: {},
+    }
+  });
+
+  server.setRequestHandler(ListToolsRequestSchema, async () => {
+    return {
+      tools: tools.map(tool => ({
+        name: tool.schema.name,
+        description: tool.schema.description,
+        inputSchema: zodToJsonSchema(tool.schema.inputSchema),
+        annotations: {
+          title: tool.schema.title,
+          readOnlyHint: tool.schema.type === 'readOnly',
+          destructiveHint: tool.schema.type === 'destructive',
+          openWorldHint: true,
+        },
+      })) as McpTool[],
+    };
+  });
+
+  server.setRequestHandler(CallToolRequestSchema, async request => {
+    const errorResult = (...messages: string[]) => ({
+      content: [{ type: 'text', text: messages.join('\n') }],
+      isError: true,
+    });
+    const tool = tools.find(tool => tool.schema.name === request.params.name);
+    if (!tool)
+      return errorResult(`Tool "${request.params.name}" not found`);
+
+
+    const modalStates = context.modalStates().map(state => state.type);
+    if (tool.clearsModalState && !modalStates.includes(tool.clearsModalState))
+      return errorResult(`The tool "${request.params.name}" can only be used when there is related modal state present.`, ...context.modalStatesMarkdown());
+    if (!tool.clearsModalState && modalStates.length)
+      return errorResult(`Tool "${request.params.name}" does not handle the modal state.`, ...context.modalStatesMarkdown());
+
+    try {
+      return await context.run(tool, request.params.arguments);
+    } catch (error) {
+      return errorResult(String(error));
+    }
+  });
+
+  const connection = new Connection(server, context);
+  return connection;
+}
+
+export class Connection {
+  readonly server: Server;
+  readonly context: Context;
+
+  constructor(server: Server, context: Context) {
+    this.server = server;
+    this.context = context;
+  }
+
+  async connect(transport: Transport) {
+    await this.server.connect(transport);
+    await new Promise<void>(resolve => {
+      this.server.oninitialized = () => resolve();
+    });
+    if (this.server.getClientVersion()?.name.includes('cursor'))
+      this.context.config.noImageResponses = true;
+  }
+
+  async close() {
+    await this.server.close();
+    await this.context.close();
+  }
+}