Rename server->core (#638)

packages/core/src/tools/tool-registry.ts

@@ -0,0 +1,187 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { FunctionDeclaration } from '@google/genai';
+import { Tool, ToolResult, BaseTool } from './tools.js';
+import { Config } from '../config/config.js';
+import { spawn, execSync } from 'node:child_process';
+import { discoverMcpTools } from './mcp-client.js';
+import { DiscoveredMCPTool } from './mcp-tool.js';
+
+type ToolParams = Record<string, unknown>;
+
+export class DiscoveredTool extends BaseTool<ToolParams, ToolResult> {
+  constructor(
+    private readonly config: Config,
+    readonly name: string,
+    readonly description: string,
+    readonly parameterSchema: Record<string, unknown>,
+  ) {
+    const discoveryCmd = config.getToolDiscoveryCommand()!;
+    const callCommand = config.getToolCallCommand()!;
+    description += `
+
+This tool was discovered from the project by executing the command \`${discoveryCmd}\` on project root.
+When called, this tool will execute the command \`${callCommand} ${name}\` on project root.
+Tool discovery and call commands can be configured in project or user settings.
+
+When called, the tool call command is executed as a subprocess.
+On success, tool output is returned as a json string.
+Otherwise, the following information is returned:
+
+Stdout: Output on stdout stream. Can be \`(empty)\` or partial.
+Stderr: Output on stderr stream. Can be \`(empty)\` or partial.
+Error: Error or \`(none)\` if no error was reported for the subprocess.
+Exit Code: Exit code or \`(none)\` if terminated by signal.
+Signal: Signal number or \`(none)\` if no signal was received.
+`;
+    super(
+      name,
+      name,
+      description,
+      parameterSchema,
+      false, // isOutputMarkdown
+      false, // canUpdateOutput
+    );
+  }
+
+  async execute(params: ToolParams): Promise<ToolResult> {
+    const callCommand = this.config.getToolCallCommand()!;
+    const child = spawn(callCommand, [this.name]);
+    child.stdin.write(JSON.stringify(params));
+    child.stdin.end();
+    let stdout = '';
+    let stderr = '';
+    child.stdout.on('data', (data) => {
+      stdout += data.toString();
+    });
+    child.stderr.on('data', (data) => {
+      stderr += data.toString();
+    });
+    let error: Error | null = null;
+    child.on('error', (err: Error) => {
+      error = err;
+    });
+    let code: number | null = null;
+    let signal: NodeJS.Signals | null = null;
+    child.on(
+      'close',
+      (_code: number | null, _signal: NodeJS.Signals | null) => {
+        code = _code;
+        signal = _signal;
+      },
+    );
+    await new Promise((resolve) => child.on('close', resolve));
+
+    // if there is any error, non-zero exit code, signal, or stderr, return error details instead of stdout
+    if (error || code !== 0 || signal || stderr) {
+      const llmContent = [
+        `Stdout: ${stdout || '(empty)'}`,
+        `Stderr: ${stderr || '(empty)'}`,
+        `Error: ${error ?? '(none)'}`,
+        `Exit Code: ${code ?? '(none)'}`,
+        `Signal: ${signal ?? '(none)'}`,
+      ].join('\n');
+      return {
+        llmContent,
+        returnDisplay: llmContent,
+      };
+    }
+
+    return {
+      llmContent: stdout,
+      returnDisplay: stdout,
+    };
+  }
+}
+
+export class ToolRegistry {
+  private tools: Map<string, Tool> = new Map();
+  private config: Config;
+
+  constructor(config: Config) {
+    this.config = config;
+  }
+
+  /**
+   * Registers a tool definition.
+   * @param tool - The tool object containing schema and execution logic.
+   */
+  registerTool(tool: Tool): void {
+    if (this.tools.has(tool.name)) {
+      // Decide on behavior: throw error, log warning, or allow overwrite
+      console.warn(
+        `Tool with name "${tool.name}" is already registered. Overwriting.`,
+      );
+    }
+    this.tools.set(tool.name, tool);
+  }
+
+  /**
+   * Discovers tools from project, if a discovery command is configured.
+   * Can be called multiple times to update discovered tools.
+   */
+  async discoverTools(): Promise<void> {
+    // remove any previously discovered tools
+    for (const tool of this.tools.values()) {
+      if (tool instanceof DiscoveredTool || tool instanceof DiscoveredMCPTool) {
+        this.tools.delete(tool.name);
+      } else {
+        // Keep manually registered tools
+      }
+    }
+    // discover tools using discovery command, if configured
+    const discoveryCmd = this.config.getToolDiscoveryCommand();
+    if (discoveryCmd) {
+      // execute discovery command and extract function declarations
+      const functions: FunctionDeclaration[] = [];
+      for (const tool of JSON.parse(execSync(discoveryCmd).toString().trim())) {
+        functions.push(...tool['function_declarations']);
+      }
+      // register each function as a tool
+      for (const func of functions) {
+        this.registerTool(
+          new DiscoveredTool(
+            this.config,
+            func.name!,
+            func.description!,
+            func.parameters! as Record<string, unknown>,
+          ),
+        );
+      }
+    }
+    // discover tools using MCP servers, if configured
+    await discoverMcpTools(this.config, this);
+  }
+
+  /**
+   * Retrieves the list of tool schemas (FunctionDeclaration array).
+   * Extracts the declarations from the ToolListUnion structure.
+   * Includes discovered (vs registered) tools if configured.
+   * @returns An array of FunctionDeclarations.
+   */
+  getFunctionDeclarations(): FunctionDeclaration[] {
+    const declarations: FunctionDeclaration[] = [];
+    this.tools.forEach((tool) => {
+      declarations.push(tool.schema);
+    });
+    return declarations;
+  }
+
+  /**
+   * Returns an array of all registered and discovered tool instances.
+   */
+  getAllTools(): Tool[] {
+    return Array.from(this.tools.values());
+  }
+
+  /**
+   * Get the definition of a specific tool.
+   */
+  getTool(name: string): Tool | undefined {
+    return this.tools.get(name);
+  }
+}