feat: improved HTTP errors for REST API (denoland#444)

This change adds middleware for the REST API that catches HTTP errors,
as defined in the Standard Library, and returns non-HTML responses. This
will make future REST API development cleaner.

Currently, responses are still responding with HTML. Perhaps, the
middleware is set up incorrectly.

e2e_test.ts

@@ -35,7 +35,6 @@ const handler = await createHandler(manifest, options);
 
 function assertResponseNotFound(resp: Response) {
   assertFalse(resp.ok);
-  assertEquals(resp.body, null);
   assertEquals(resp.status, Status.NotFound);
 }
 
@@ -204,7 +203,9 @@ Deno.test("[e2e]", async (test) => {
     const req = new Request("http://localhost/api/items/" + item.id);
 
     const resp1 = await handler(req);
-    assertResponseNotFound(resp1);
+    assertFalse(resp1.ok);
+    assertEquals(await resp1.text(), "Item not found");
+    assertEquals(resp1.status, Status.NotFound);
 
     await createItem(item);
     const resp2 = await handler(req);
@@ -221,7 +222,9 @@ Deno.test("[e2e]", async (test) => {
     const req = new Request(`http://localhost/api/items/${item.id}/comments`);
 
     const resp1 = await handler(req);
-    assertResponseNotFound(resp1);
+    assertFalse(resp1.ok);
+    assertEquals(await resp1.text(), "Item not found");
+    assertEquals(resp1.status, Status.NotFound);
 
     await createItem(item);
     await createComment(comment);
@@ -250,7 +253,9 @@ Deno.test("[e2e]", async (test) => {
     const req = new Request("http://localhost/api/users/" + user.login);
 
     const resp1 = await handler(req);
-    assertResponseNotFound(resp1);
+    assertFalse(resp1.ok);
+    assertEquals(await resp1.text(), "User not found");
+    assertEquals(resp1.status, Status.NotFound);
 
     await createUser(user);
     const resp2 = await handler(req);
@@ -288,7 +293,6 @@ Deno.test("[e2e]", async (test) => {
 
     const resp1 = await handler(new Request(url));
     assertFalse(resp1.ok);
-    assertEquals(resp1.body, null);
     assertEquals(resp1.status, Status.Unauthorized);
 
     await createUser(user);

fresh.gen.ts

@@ -10,32 +10,33 @@ import * as $4 from "./routes/account/_middleware.ts";
 import * as $5 from "./routes/account/index.tsx";
 import * as $6 from "./routes/account/manage.ts";
 import * as $7 from "./routes/account/upgrade.ts";
-import * as $8 from "./routes/api/items/[id]/comments.ts";
-import * as $9 from "./routes/api/items/[id]/index.ts";
-import * as $10 from "./routes/api/items/[id]/vote.ts";
-import * as $11 from "./routes/api/items/index.ts";
-import * as $12 from "./routes/api/me/notifications.ts";
-import * as $13 from "./routes/api/me/votes.ts";
-import * as $14 from "./routes/api/stripe-webhooks.ts";
-import * as $15 from "./routes/api/users/[login]/index.ts";
-import * as $16 from "./routes/api/users/[login]/items.ts";
-import * as $17 from "./routes/api/users/index.ts";
-import * as $18 from "./routes/blog/[slug].tsx";
-import * as $19 from "./routes/blog/index.tsx";
-import * as $20 from "./routes/dashboard/_middleware.ts";
-import * as $21 from "./routes/dashboard/index.tsx";
-import * as $22 from "./routes/dashboard/stats.tsx";
-import * as $23 from "./routes/dashboard/users.tsx";
-import * as $24 from "./routes/feed.ts";
-import * as $25 from "./routes/index.tsx";
-import * as $26 from "./routes/items/[id].tsx";
-import * as $27 from "./routes/notifications/[id].ts";
-import * as $28 from "./routes/notifications/_middleware.ts";
-import * as $29 from "./routes/notifications/index.tsx";
-import * as $30 from "./routes/pricing.tsx";
-import * as $31 from "./routes/submit/_middleware.tsx";
-import * as $32 from "./routes/submit/index.tsx";
-import * as $33 from "./routes/users/[login].tsx";
+import * as $8 from "./routes/api/_middleware.ts";
+import * as $9 from "./routes/api/items/[id]/comments.ts";
+import * as $10 from "./routes/api/items/[id]/index.ts";
+import * as $11 from "./routes/api/items/[id]/vote.ts";
+import * as $12 from "./routes/api/items/index.ts";
+import * as $13 from "./routes/api/me/notifications.ts";
+import * as $14 from "./routes/api/me/votes.ts";
+import * as $15 from "./routes/api/stripe-webhooks.ts";
+import * as $16 from "./routes/api/users/[login]/index.ts";
+import * as $17 from "./routes/api/users/[login]/items.ts";
+import * as $18 from "./routes/api/users/index.ts";
+import * as $19 from "./routes/blog/[slug].tsx";
+import * as $20 from "./routes/blog/index.tsx";
+import * as $21 from "./routes/dashboard/_middleware.ts";
+import * as $22 from "./routes/dashboard/index.tsx";
+import * as $23 from "./routes/dashboard/stats.tsx";
+import * as $24 from "./routes/dashboard/users.tsx";
+import * as $25 from "./routes/feed.ts";
+import * as $26 from "./routes/index.tsx";
+import * as $27 from "./routes/items/[id].tsx";
+import * as $28 from "./routes/notifications/[id].ts";
+import * as $29 from "./routes/notifications/_middleware.ts";
+import * as $30 from "./routes/notifications/index.tsx";
+import * as $31 from "./routes/pricing.tsx";
+import * as $32 from "./routes/submit/_middleware.tsx";
+import * as $33 from "./routes/submit/index.tsx";
+import * as $34 from "./routes/users/[login].tsx";
 import * as $$0 from "./islands/Chart.tsx";
 import * as $$1 from "./islands/CommentsList.tsx";
 import * as $$2 from "./islands/ItemsList.tsx";
@@ -53,32 +54,33 @@ const manifest = {
     "./routes/account/index.tsx": $5,
     "./routes/account/manage.ts": $6,
     "./routes/account/upgrade.ts": $7,
-    "./routes/api/items/[id]/comments.ts": $8,
-    "./routes/api/items/[id]/index.ts": $9,
-    "./routes/api/items/[id]/vote.ts": $10,
-    "./routes/api/items/index.ts": $11,
-    "./routes/api/me/notifications.ts": $12,
-    "./routes/api/me/votes.ts": $13,
-    "./routes/api/stripe-webhooks.ts": $14,
-    "./routes/api/users/[login]/index.ts": $15,
-    "./routes/api/users/[login]/items.ts": $16,
-    "./routes/api/users/index.ts": $17,
-    "./routes/blog/[slug].tsx": $18,
-    "./routes/blog/index.tsx": $19,
-    "./routes/dashboard/_middleware.ts": $20,
-    "./routes/dashboard/index.tsx": $21,
-    "./routes/dashboard/stats.tsx": $22,
-    "./routes/dashboard/users.tsx": $23,
-    "./routes/feed.ts": $24,
-    "./routes/index.tsx": $25,
-    "./routes/items/[id].tsx": $26,
-    "./routes/notifications/[id].ts": $27,
-    "./routes/notifications/_middleware.ts": $28,
-    "./routes/notifications/index.tsx": $29,
-    "./routes/pricing.tsx": $30,
-    "./routes/submit/_middleware.tsx": $31,
-    "./routes/submit/index.tsx": $32,
-    "./routes/users/[login].tsx": $33,
+    "./routes/api/_middleware.ts": $8,
+    "./routes/api/items/[id]/comments.ts": $9,
+    "./routes/api/items/[id]/index.ts": $10,
+    "./routes/api/items/[id]/vote.ts": $11,
+    "./routes/api/items/index.ts": $12,
+    "./routes/api/me/notifications.ts": $13,
+    "./routes/api/me/votes.ts": $14,
+    "./routes/api/stripe-webhooks.ts": $15,
+    "./routes/api/users/[login]/index.ts": $16,
+    "./routes/api/users/[login]/items.ts": $17,
+    "./routes/api/users/index.ts": $18,
+    "./routes/blog/[slug].tsx": $19,
+    "./routes/blog/index.tsx": $20,
+    "./routes/dashboard/_middleware.ts": $21,
+    "./routes/dashboard/index.tsx": $22,
+    "./routes/dashboard/stats.tsx": $23,
+    "./routes/dashboard/users.tsx": $24,
+    "./routes/feed.ts": $25,
+    "./routes/index.tsx": $26,
+    "./routes/items/[id].tsx": $27,
+    "./routes/notifications/[id].ts": $28,
+    "./routes/notifications/_middleware.ts": $29,
+    "./routes/notifications/index.tsx": $30,
+    "./routes/pricing.tsx": $31,
+    "./routes/submit/_middleware.tsx": $32,
+    "./routes/submit/index.tsx": $33,
+    "./routes/users/[login].tsx": $34,
   },
   islands: {
     "./islands/Chart.tsx": $$0,

routes/api/_middleware.ts

@@ -0,0 +1,20 @@
+// Copyright 2023 the Deno authors. All rights reserved. MIT license.
+
+import { type MiddlewareHandlerContext, Status } from "$fresh/server.ts";
+import { isHttpError } from "std/http/http_errors.ts";
+
+export async function handler(
+  _req: Request,
+  ctx: MiddlewareHandlerContext,
+) {
+  try {
+    return await ctx.next();
+  } catch (error) {
+    return isHttpError(error)
+      ? new Response(error.message, {
+        status: error.status,
+        headers: error.headers,
+      })
+      : new Response(error.message, { status: Status.InternalServerError });
+  }
+}

routes/api/items/[id]/comments.ts

@@ -1,13 +1,14 @@
-import { Handlers, Status } from "$fresh/server.ts";
+import type { Handlers } from "$fresh/server.ts";
 import { collectValues, getItem, listCommentsByItem } from "@/utils/db.ts";
+import { errors } from "std/http/http_errors.ts";
 import { getCursor } from "@/utils/http.ts";
 
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
 export const handler: Handlers = {
   async GET(req, ctx) {
     const itemId = ctx.params.id;
     const item = await getItem(itemId);
-    if (item === null) return new Response(null, { status: Status.NotFound });
+    if (item === null) throw new errors.NotFound("Item not found");
 
     const url = new URL(req.url);
     const iter = listCommentsByItem(itemId, {

routes/api/items/[id]/index.ts

@@ -1,12 +1,12 @@
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
-import { type Handlers, Status } from "$fresh/server.ts";
+import type { Handlers } from "$fresh/server.ts";
 import { getItem } from "@/utils/db.ts";
+import { errors } from "std/http/http_errors.ts";
 
 export const handler: Handlers = {
   async GET(_req, ctx) {
     const item = await getItem(ctx.params.id);
-    return item === null
-      ? new Response(null, { status: Status.NotFound })
-      : Response.json(item);
+    if (item === null) throw new errors.NotFound("Item not found");
+    return Response.json(item);
   },
 };

routes/api/items/[id]/vote.ts

@@ -10,18 +10,19 @@ import {
   newNotificationProps,
   newVoteProps,
 } from "@/utils/db.ts";
+import { errors } from "std/http/http_errors.ts";
 
 export const handler: Handlers<undefined, State> = {
   async POST(_req, ctx) {
     const itemId = ctx.params.id;
     const item = await getItem(itemId);
-    if (item === null) return new Response(null, { status: Status.NotFound });
+    if (item === null) throw new errors.NotFound("Item not found");
 
     if (ctx.state.sessionId === undefined) {
-      return new Response(null, { status: Status.Unauthorized });
+      throw new errors.Unauthorized("User must be signed in");
     }
     const user = await getUserBySession(ctx.state.sessionId);
-    if (user === null) return new Response(null, { status: Status.NotFound });
+    if (user === null) throw new errors.NotFound("User not found");
 
     await createVote({
       itemId,
@@ -44,13 +45,13 @@ export const handler: Handlers<undefined, State> = {
   async DELETE(_req, ctx) {
     const itemId = ctx.params.id;
     const item = await getItem(itemId);
-    if (item === null) return new Response(null, { status: Status.NotFound });
+    if (item === null) throw new errors.NotFound("Item not found");
 
     if (ctx.state.sessionId === undefined) {
-      return new Response(null, { status: Status.Unauthorized });
+      throw new errors.Unauthorized("User must be signed in");
     }
     const user = await getUserBySession(ctx.state.sessionId);
-    if (user === null) return new Response(null, { status: Status.NotFound });
+    if (user === null) throw new errors.NotFound("User not found");
 
     await deleteVote({ itemId, userLogin: user.login });
 

routes/api/me/notifications.ts

@@ -1,21 +1,22 @@
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
-import { type Handlers, Status } from "$fresh/server.ts";
+import type { Handlers } from "$fresh/server.ts";
 import {
   collectValues,
   getUserBySession,
   listNotificationsByUser,
 } from "@/utils/db.ts";
 import { getCursor } from "@/utils/http.ts";
 import { State } from "@/routes/_middleware.ts";
+import { errors } from "std/http/http_errors.ts";
 
 export const handler: Handlers<undefined, State> = {
   async GET(req, ctx) {
     if (ctx.state.sessionId === undefined) {
-      return new Response(null, { status: Status.Unauthorized });
+      throw new errors.Unauthorized("User must be signed in");
     }
 
     const user = await getUserBySession(ctx.state.sessionId);
-    if (user === null) return new Response(null, { status: Status.NotFound });
+    if (user === null) throw new errors.NotFound("User not found");
 
     const url = new URL(req.url);
     const iter = listNotificationsByUser(user.login, {

routes/api/me/votes.ts

@@ -1,20 +1,21 @@
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
-import { type Handlers, Status } from "$fresh/server.ts";
+import type { Handlers } from "$fresh/server.ts";
 import type { State } from "@/routes/_middleware.ts";
 import {
   collectValues,
   getUserBySession,
   listItemsVotedByUser,
 } from "@/utils/db.ts";
+import { errors } from "std/http/http_errors.ts";
 
 export const handler: Handlers<undefined, State> = {
   async GET(_req, ctx) {
     if (ctx.state.sessionId === undefined) {
-      return new Response(null, { status: Status.Unauthorized });
+      throw new errors.Unauthorized("User must be signed in");
     }
 
     const user = await getUserBySession(ctx.state.sessionId);
-    if (user === null) return new Response(null, { status: Status.NotFound });
+    if (user === null) throw new errors.NotFound("User not found");
 
     const iter = listItemsVotedByUser(user.login);
     const items = await collectValues(iter);

routes/api/stripe-webhooks.ts

@@ -1,8 +1,9 @@
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
-import type { Handlers } from "$fresh/server.ts";
+import { type Handlers, Status } from "$fresh/server.ts";
 import { stripe } from "@/utils/payments.ts";
 import Stripe from "stripe";
 import { getUserByStripeCustomer, updateUser } from "@/utils/db.ts";
+import { errors } from "std/http/http_errors.ts";
 
 const cryptoProvider = Stripe.createSubtleCryptoProvider();
 
@@ -12,8 +13,8 @@ export const handler: Handlers = {
    * 1. customer.subscription.created (when a user subscribes to the premium plan)
    * 2. customer.subscription.deleted (when a user cancels the premium plan)
    */
-  async POST(req, ctx) {
-    if (stripe === undefined) return await ctx.renderNotFound();
+  async POST(req) {
+    if (stripe === undefined) throw new errors.NotFound();
 
     const body = await req.text();
     const signature = req.headers.get("stripe-signature")!;
@@ -39,20 +40,18 @@ export const handler: Handlers = {
     switch (event.type) {
       case "customer.subscription.created": {
         const user = await getUserByStripeCustomer(customer);
-        if (!user) return new Response(null, { status: 400 });
+        if (user === null) throw new errors.NotFound("User not found");
         await updateUser({ ...user, isSubscribed: true });
-        return new Response(null, { status: 201 });
+        return new Response(null, { status: Status.Created });
       }
       case "customer.subscription.deleted": {
         const user = await getUserByStripeCustomer(customer);
-        if (!user) return new Response(null, { status: 400 });
+        if (user === null) throw new errors.NotFound("User not found");
         await updateUser({ ...user, isSubscribed: false });
-        return new Response(null, { status: 202 });
+        return new Response(null, { status: Status.Accepted });
       }
       default: {
-        const message = `Event type not supported: ${event.type}`;
-        console.error(message);
-        return new Response(message, { status: 400 });
+        throw new errors.BadRequest("Event type not supported");
       }
     }
   },

routes/api/users/[login]/index.ts

@@ -1,12 +1,12 @@
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
-import { Handlers, Status } from "$fresh/server.ts";
+import type { Handlers } from "$fresh/server.ts";
 import { getUser } from "@/utils/db.ts";
+import { errors } from "std/http/http_errors.ts";
 
 export const handler: Handlers = {
   async GET(_req, ctx) {
     const user = await getUser(ctx.params.login);
-    return user === null
-      ? new Response(null, { status: Status.NotFound })
-      : Response.json(user);
+    if (user === null) throw new errors.NotFound("User not found");
+    return Response.json(user);
   },
 };

routes/api/users/[login]/items.ts

@@ -1,12 +1,13 @@
 // Copyright 2023 the Deno authors. All rights reserved. MIT license.
-import { Handlers, Status } from "$fresh/server.ts";
+import type { Handlers } from "$fresh/server.ts";
 import { collectValues, getUser, listItemsByUser } from "@/utils/db.ts";
 import { getCursor } from "@/utils/http.ts";
+import { errors } from "std/http/http_errors.ts";
 
 export const handler: Handlers = {
   async GET(req, ctx) {
     const user = await getUser(ctx.params.login);
-    if (user === null) return new Response(null, { status: Status.NotFound });
+    if (user === null) throw new errors.NotFound("User not found");
 
     const url = new URL(req.url);
     const iter = listItemsByUser(ctx.params.login, {