Merge pull request #16 from Applura/problem-details

convert: every error to a problem details object

Author: gabesullice

index.js

@@ -1,28 +1,3 @@
 import Client, { bootstrap } from "./src/client.js";
-import {
-  ImplementationError,
-  LibraryError,
-  MissingContentTypeError,
-  RequestError,
-  ResponseError,
-  ServerError,
-  UnexpectedContentError,
-  UnexpectedContentTypeError,
-  UnprocessableResponseError,
-  UsageError,
-} from "./src/errors.js";
-
 export default Client;
 export { bootstrap };
-export {
-  ImplementationError,
-  LibraryError,
-  MissingContentTypeError,
-  RequestError,
-  ResponseError,
-  ServerError,
-  UnexpectedContentError,
-  UnexpectedContentTypeError,
-  UnprocessableResponseError,
-  UsageError,
-};

src/client.js

@@ -1,5 +1,6 @@
 import {
   ImplementationError,
+  LibraryError,
   MissingContentTypeError,
   RequestError,
   ServerError,
@@ -122,7 +123,7 @@ export default function Client(initialURL) {
       return;
     }
     lastResource = resource || lastResource;
-    lastProblem = problem;
+    lastProblem = problem instanceof LibraryError ? problem.detail : problem;
     lastURL = url || lastURL;
     send();
   };
@@ -200,7 +201,6 @@ export default function Client(initialURL) {
         mimeType.startsWith("application/problem+json"))
     ) {
       const problem = new UnexpectedContentTypeError(
-        response,
         `the server responded in with an unrecognizable media type: ${mimeType}`,
         { response },
       );
@@ -251,25 +251,31 @@ export default function Client(initialURL) {
       update(id, { resource, url });
       return true;
     }
-    const errorDetails = (doc.errors || []).filter((e) => e.detail).map((e) =>
-      `detail: ${e.detail}`
+    console.assert(
+      mimeType.startsWith("application/vnd.api+json") ||
+        mimeType.startsWith("application/problem+json"),
     );
+    const errorDetail = mimeType.startsWith("application/problem+json")
+      ? doc.detail
+      : (doc.errors || []).filter((e) => e.detail).map((e) =>
+        `detail: ${e.detail}`
+      ).join(", ");
     if (response.status >= 400 && response.status <= 499) {
       const problem = new RequestError(
         [
           "request error",
           `${response.status} ${response.statusText}`,
-          ...errorDetails,
+          errorDetail,
         ].join(": "),
-        { doc, response },
+        { response },
       );
       update(id, { problem, url });
     } else if (response.status >= 500 && response.status <= 599) {
       const problem = new ServerError(response, [
         "response error",
         `${response.status} ${response.statusText}`,
-        ...errorDetails,
-      ], { doc, response });
+        errorDetail,
+      ], { response });
       update(id, { problem, url });
     } else {
       throw new ImplementationError(

src/client_test.js

@@ -2,10 +2,8 @@ import Client, { isLocalURL } from "./client.js";
 import {
   assert,
   assertEquals,
-  assertInstanceOf,
 } from "https://deno.land/std@0.185.0/testing/asserts.ts";
 import TestServer from "./internal/testing/server.js";
-import { UnexpectedContentTypeError } from "./errors.js";
 
 Deno.test("Client", async (t) => {
   const serverOptions = { hostname: "0.0.0.0", port: 3003 };
@@ -135,7 +133,10 @@ Deno.test("Client", async (t) => {
       let { status } = client.response();
       assertEquals(status, 200);
       assertEquals(resource, undefined);
-      assertInstanceOf(problem, UnexpectedContentTypeError);
+      assertEquals(
+        problem.type,
+        "https://docs.applura.com/client/v2/errors#UnexpectedContentTypeError",
+      );
       // Get a good response.
       server.respondWith(
         new Response(
@@ -163,7 +164,10 @@ Deno.test("Client", async (t) => {
       ({ status } = client.response());
       assertEquals(status, 200);
       assertEquals(resource.id, "200 resource");
-      assertInstanceOf(problem, UnexpectedContentTypeError);
+      assertEquals(
+        problem.type,
+        "https://docs.applura.com/client/v2/errors#UnexpectedContentTypeError",
+      );
       client.stop();
     });
   });

src/errors.js

@@ -4,11 +4,18 @@ export class LibraryError extends Error {
     super(message, options);
     this.name = "LibraryError";
   }
+  get detail() {
+    return {
+      type: `https://docs.applura.com/client/v2/errors#${this.name}`,
+      title: this.name,
+      detail: this.message,
+    };
+  }
 }
 
 // Raised when the implementation of this library has caused an error. For example, when a known edge case has not been
 // handled.
-export class ImplementationError extends Error {
+export class ImplementationError extends LibraryError {
   constructor(message, options) {
     super(message, options);
     this.name = "ImplementationError";
@@ -23,22 +30,34 @@ export class UsageError extends LibraryError {
   }
 }
 
-// Raised when an HTTP request causes an HTTP client error, i.e. for HTTP status codes >=300 and <=399.
-export class RequestError extends LibraryError {
-  constructor(message, { doc, response, ...options }) {
+// Raised when an HTTP response is in error, i.e. for HTTP status codes >=400.
+export class HTTPError extends LibraryError {
+  constructor(message, { response, ...options }) {
     super(message, options);
     this.name = "RequestError";
-    Object.defineProperty(this, "doc", { value: doc });
     Object.defineProperty(this, "response", { value: response });
   }
+  get detail() {
+    return {
+      ...super.detail,
+      status: this.response.status,
+    };
+  }
+}
+
+// Raised when an HTTP request causes an HTTP client error, i.e. for HTTP status codes >=400 and <=499.
+export class RequestError extends HTTPError {
+  constructor(message, options) {
+    super(message, options);
+    this.name = "RequestError";
+  }
 }
 
 // Raised when an HTTP response causes an error.
-export class ResponseError extends LibraryError {
-  constructor(message, { doc, response, ...options }) {
-    super(message, { ...options, doc: { value: doc } });
+export class ResponseError extends HTTPError {
+  constructor(message, options) {
+    super(message, options);
     this.name = "ResponseError";
-    Object.defineProperty(this, "response", { value: response });
   }
 }