feat: add type declaration file

README.md

@@ -204,16 +204,57 @@ reqJSON.use((context, next) => {
 
 Context contains these attributes:
 
-* `path`
-* `method`
-* `url`
-* `data`
-* `options`
-* `status` (response only)
-* `response` (response only)
-* `headers` (setting for request, getting for response)
-* `header` (alias to `headers`)
-* `xhr`
+```js
+/**
+ * The path to use for the request, with parameters defined.
+ */
+path: string
+
+/**
+ * The HTTP method to use for the request (e.g. "POST", "GET", "PUT",   "DELETE").
+ */
+method: string
+
+/**
+ * The URL to which the request is sent.
+ */
+url: string
+
+/**
+ * The data to be sent.
+ */
+data: any
+
+/**
+ * The options to use for the request.
+ */
+options: object
+
+/**
+ * The HTTP status of the response. Only available when the request   completes.
+ */
+status?: number
+
+/**
+ * The parsed response. Only available when the request completes.
+ */
+response?: string | object
+
+/**
+ * The request headers before the request is sent, the response   headers when the request completes.
+ */
+headers: object
+
+/**
+ * Alias to `headers`
+ */
+header: object
+
+/**
+ * The original XMLHttpRequest object.
+ */
+xhr: XMLHttpRequest
+```
 
 ### Reject when status 4xx or 5xx
 
@@ -235,7 +276,7 @@ reqJSON.use((context, next) => {
   return next()
     .then(() => {
       if (context.status >= 400) {
-        throw new Error(context.response);
+throw new Error(context.response);
       }
     });
 });

index.d.ts

@@ -0,0 +1,126 @@
+declare namespace ReqJSON {
+  interface HTTPMethod {
+    /**
+     * Send HTTP request.
+     *
+     * @param data The data to be sent.
+     * @param options The options to use for each requests to the resource.
+     */
+    (data?: any, options?: object): Promise<string | object>
+  }
+
+  interface ShortHandMethod {
+    /**
+     * Send HTTP request.
+     *
+     * @param path The path to use for the request, with parameters defined.
+     * @param data The data to be sent.
+     * @param options The options to use for each requests to the resource.
+     */
+    (path?: string, data?: any, options?: object): Promise<string | object>
+  }
+
+  interface RESTfulMethods {
+    get: HTTPMethod
+    post: HTTPMethod
+    put: HTTPMethod
+    delete: HTTPMethod
+  }
+
+  /**
+   * ReqJSON request context
+   */
+  interface Context {
+    /**
+     * The path to use for the request, with parameters defined.
+     */
+    path: string
+
+    /**
+     * The HTTP method to use for the request (e.g. "POST", "GET", "PUT", "DELETE").
+     */
+    method: string
+
+    /**
+     * The URL to which the request is sent.
+     */
+    url: string
+
+    /**
+     * The data to be sent.
+     */
+    data: any
+
+    /**
+     * The options to use for the request.
+     */
+    options: object
+
+    /**
+     * The HTTP status of the response. Only available when the request completes.
+     */
+    status?: number
+
+    /**
+     * The parsed response. Only available when the request completes.
+     */
+    response?: string | object
+
+    /**
+     * The request headers before the request is sent, the response headers when the request completes.
+     */
+    headers: object
+
+    /**
+     * Alias to `headers`
+     */
+    header: object
+
+    /**
+     * The original XMLHttpRequest object.
+     */
+    xhr: XMLHttpRequest
+  }
+
+  interface Middleware extends Function {
+    /**
+     * ReqJSON middleware, similar to Koa.js middleware.
+     * 
+     * @param context ReqJSON request context
+     * @param next ReqJSON Middleware
+     */
+    (context?: Context, next?: Middleware): any
+  }
+}
+
+declare class ReqJSON {
+  /**
+   * Create a new ReqJSON instance
+   */
+  constructor();
+
+  /**
+   * Define a RESTful resource.
+   * 
+   * @param path The path to use for the request, with parameters defined.
+   * @param options The options to use for each requests to the resource.
+   */
+  resource(
+    path: string,
+    options: object
+  ): ReqJSON.RESTfulMethods
+
+  /**
+   * Register a ReqJSON middleware
+   * 
+   * @param middleware A ReqJSON middleware
+   */
+  use(middleware: ReqJSON.Middleware): this
+
+  get: ReqJSON.ShortHandMethod
+  post: ReqJSON.ShortHandMethod
+  put: ReqJSON.ShortHandMethod
+  delete: ReqJSON.ShortHandMethod
+}
+
+export = ReqJSON