WeChat Mini Program Dev MCP

Instructions

Implementation Reference

• src/tools/element.ts:355-384 (handler)

  The execute handler for the element_getSize tool. It resolves the element using the provided selector(s), calls element.size() to get dimensions, and formats the result as JSON text.

  execute: async (rawArgs, context: ToolContext) => {
    const args = getElementSizeParameters.parse(rawArgs ?? {});
    return manager.withPage(
      context.log,
      { overrides: args.connection },
      async (page) => {
        const element = await resolveElement(
          page,
          args.selector,
          args.innerSelector
        );
  
        if (typeof element.size !== "function") {
          throw new UserError(
            `元素 "${args.selector}" 不支持获取大小。`
          );
        }
  
        const size = await element.size();
        return toTextResult(
          formatJson({
            selector: args.selector,
            innerSelector: args.innerSelector ?? null,
            width: toSerializableValue(size.width),
            height: toSerializableValue(size.height),
          })
        );
      }
    );
  },

• src/tools/element.ts:59-62 (schema)

  Zod schema for input validation of the element_getSize tool parameters: selector and optional innerSelector, extending connection schema.

  const getElementSizeParameters = connectionContainerSchema.extend({
    selector: z.string().trim().min(1),
    innerSelector: z.string().trim().min(1).optional(),
  });

• src/tools/element.ts:350-386 (registration)

  Factory function that defines and returns the complete tool object for 'element_getSize', including name, description, schema, and handler.

  function createGetElementSizeTool(manager: WeappAutomatorManager): AnyTool {
    return {
      name: "element_getSize",
      description: "获取元素大小(宽度和高度)。如需获取自定义组件内部元素的大小，请使用 innerSelector 参数：selector 设为组件 ID 选择器(如 #my-component)，innerSelector 设为组件内部元素的选择器。",
      parameters: getElementSizeParameters,
      execute: async (rawArgs, context: ToolContext) => {
        const args = getElementSizeParameters.parse(rawArgs ?? {});
        return manager.withPage(
          context.log,
          { overrides: args.connection },
          async (page) => {
            const element = await resolveElement(
              page,
              args.selector,
              args.innerSelector
            );
  
            if (typeof element.size !== "function") {
              throw new UserError(
                `元素 "${args.selector}" 不支持获取大小。`
              );
            }
  
            const size = await element.size();
            return toTextResult(
              formatJson({
                selector: args.selector,
                innerSelector: args.innerSelector ?? null,
                width: toSerializableValue(size.width),
                height: toSerializableValue(size.height),
              })
            );
          }
        );
      },
    };
  }

• src/tools/element.ts:70-84 (registration)

  Registers element_getSize tool within the createElementTools function by including its factory in the tools array.

  export function createElementTools(
    manager: WeappAutomatorManager
  ): AnyTool[] {
    return [
      createTapElementTool(manager),
      createInputTextTool(manager),
      createCallElementMethodTool(manager),
      createGetElementDataTool(manager),
      createSetElementDataTool(manager),
      createGetInnerElementTool(manager),
      createGetInnerElementsTool(manager),
      createGetElementSizeTool(manager),
      createGetElementWxmlTool(manager),
    ];
  }

• src/tools.ts:7-13 (registration)

  Aggregates and registers all tools, including element tools (containing element_getSize), in the top-level createTools function.

  export function createTools(manager: WeappAutomatorManager): AnyTool[] {
    return [
      ...createApplicationTools(manager),
      ...createPageTools(manager),
      ...createElementTools(manager),
    ];
  }

• src/index.ts:17-17 (registration)

  Final registration of all tools, including element_getSize, to the FastMCP server.

  server.addTools(createTools(manager));