Implemented http-fetch's own exception. (#727)

- User can handle HTTP response body and headers.

Ref. #723

Author: tokuhirom

lib/exceptions.ts

@@ -42,3 +42,14 @@ export class HTTPError extends Error {
     super(message);
   }
 }
+
+export class HTTPFetchError extends Error {
+  constructor(
+    public statusCode: number,
+    public statusMessage: string,
+    public headers: Headers,
+    public body: string,
+  ) {
+    super(`${statusCode} - ${statusMessage}`);
+  }
+}

lib/http-fetch.ts

@@ -1,5 +1,5 @@
 import { Readable } from "stream";
-import { HTTPError } from "./exceptions";
+import { HTTPError, HTTPFetchError } from "./exceptions";
 import * as qs from "querystring";
 
 const pkg = require("../package.json");
@@ -35,7 +35,7 @@ export default class HTTPFetchClient {
     const response = await fetch(requestUrl, {
       headers: this.defaultHeaders,
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return response.json();
   }
 
@@ -75,7 +75,7 @@ export default class HTTPFetchClient {
       },
       body: JSON.stringify(body),
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return this.responseParse(response);
   }
 
@@ -99,7 +99,7 @@ export default class HTTPFetchClient {
       },
       body: JSON.stringify(body),
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return this.responseParse(response);
   }
 
@@ -113,7 +113,7 @@ export default class HTTPFetchClient {
       },
       body: qs.stringify(body),
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return response.json();
   }
 
@@ -126,7 +126,7 @@ export default class HTTPFetchClient {
       },
       body: form,
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return response.json();
   }
 
@@ -144,7 +144,7 @@ export default class HTTPFetchClient {
       },
       body: form,
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return response.json();
   }
   public async postBinaryContent<T>(url: string, body: Blob): Promise<T> {
@@ -157,7 +157,7 @@ export default class HTTPFetchClient {
       },
       body: body,
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return response.json();
   }
 
@@ -172,17 +172,17 @@ export default class HTTPFetchClient {
         ...this.defaultHeaders,
       },
     });
-    this.checkResponseStatus(response);
+    await this.checkResponseStatus(response);
     return response.json();
   }
 
-  private checkResponseStatus(response: Response) {
+  private async checkResponseStatus(response: Response) {
     if (!response.ok) {
-      throw new HTTPError(
-        "HTTP request failed",
+      throw new HTTPFetchError(
         response.status,
         response.statusText,
-        undefined,
+        response.headers,
+        await response.text()
       );
     }
   }

test/http-fetch.spec.ts

@@ -1,5 +1,5 @@
 import { deepEqual, equal, ok } from "assert";
-import { HTTPError } from "../lib";
+import { HTTPError, HTTPFetchError } from "../lib";
 import HTTPFetchClient from "../lib/http-fetch";
 import { getStreamData } from "./helpers/stream";
 import { http, HttpResponse } from "msw";
@@ -211,17 +211,19 @@ describe("http(fetch)", () => {
       http.get(baseURL + "/404", async ({ request, params, cookies }) => {
         scope.done();
         equal(request.headers.get("user-agent"), `${pkg.name}/${pkg.version}`);
-        return HttpResponse.json(404, { status: 404 });
+        return HttpResponse.json({reason: "not found"}, { status: 404 });
       }),
     );
 
     try {
       await client.get(`/404`);
       ok(false);
     } catch (err) {
-      ok(err instanceof HTTPError);
+      ok(err instanceof HTTPFetchError);
       equal(scope.isDone(), true);
       equal(err.statusCode, 404);
+      equal(err.headers.get('content-type'), "application/json");
+      equal(err.body, "{\"reason\":\"not found\"}");
     }
   });