├── .gitattributes
├── .github
    └── workflows
    │   └── ci.yml
├── .gitignore
├── .vscode
    └── settings.json
├── README.md
├── deno.json
└── main.ts


/.gitattributes:
--------------------------------------------------------------------------------
1 | *  text=auto  eol=lf
2 | 


--------------------------------------------------------------------------------
/.github/workflows/ci.yml:
--------------------------------------------------------------------------------
 1 | name: ci
 2 | 
 3 | on: [push, pull_request]
 4 | 
 5 | jobs:
 6 |   build:
 7 |     name: ${{ matrix.kind }} ${{ matrix.os }}
 8 |     runs-on: ${{ matrix.os }}
 9 |     strategy:
10 |       matrix:
11 |         os: [macOS-latest, ubuntu-latest, windows-latest]
12 | 
13 |     steps:
14 |       - uses: actions/checkout@v3
15 |       - name: Setup Deno
16 |         uses: denoland/setup-deno@v1
17 | 
18 |       - name: Format
19 |         run: deno fmt --check
20 | 
21 |       - name: Check
22 |         run: deno check --remote main.ts
23 | 
24 |       - name: Lint
25 |         run: deno lint
26 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
1 | *.swp
2 | *.tmp
3 | *.log
4 | 


--------------------------------------------------------------------------------
/.vscode/settings.json:
--------------------------------------------------------------------------------
1 | {
2 |   "deno.enable": true,
3 |   "deno.lint": true,
4 |   "deno.unstable": false
5 | }
6 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # Deno Deploy CORS Proxy
 2 | 
 3 | https://cors.deno.dev
 4 | 
 5 | ## Usage
 6 | 
 7 | Before:
 8 | 
 9 | ```js
10 | const response = await fetch("https://xxxx.com/api");
11 | // Uncaught TypeError: Failed to fetch
12 | // Access to fetch at 'https://xxxx.com/api' from origin 'http://localhost'
13 | // has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is
14 | // present on the requested resource.
15 | // If an opaque response serves your needs, set the request's mode to 'no-cors'
16 | // to fetch the resource with CORS disabled.
17 | ```
18 | 
19 | After:
20 | 
21 | ```js
22 | const response = await fetch("https://cors.deno.dev/https://xxxx.com/api");
23 | const json = await response.json();
24 | ```
25 | 


--------------------------------------------------------------------------------
/deno.json:
--------------------------------------------------------------------------------
1 | {
2 |   "tasks": {
3 |     "start": "deno run -A --watch main.ts"
4 |   }
5 | }
6 | 


--------------------------------------------------------------------------------
/main.ts:
--------------------------------------------------------------------------------
 1 | import { serve } from "https://deno.land/std@0.181.0/http/server.ts";
 2 | import { CSS, render } from "https://deno.land/x/gfm@0.1.22/mod.ts";
 3 | 
 4 | function addCorsIfNeeded(response: Response) {
 5 |   const headers = new Headers(response.headers);
 6 | 
 7 |   if (!headers.has("access-control-allow-origin")) {
 8 |     headers.set("access-control-allow-origin", "*");
 9 |   }
10 | 
11 |   return headers;
12 | }
13 | 
14 | function isUrl(url: string) {
15 |   if (!url.startsWith("http://") && !url.startsWith("https://")) {
16 |     return false;
17 |   }
18 | 
19 |   try {
20 |     new URL(url);
21 |     return true;
22 |   } catch {
23 |     return false;
24 |   }
25 | }
26 | 
27 | async function handleRequest(request: Request) {
28 |   const { pathname, search } = new URL(request.url);
29 |   const url = pathname.substring(1) + search;
30 | 
31 |   if (isUrl(url)) {
32 |     console.log("proxy to %s", url);
33 |     const corsHeaders = addCorsIfNeeded(new Response());
34 |     if (request.method.toUpperCase() === "OPTIONS") {
35 |       return new Response(null, { headers: corsHeaders });
36 |     }
37 | 
38 |     const response = await fetch(url, request);
39 |     const headers = addCorsIfNeeded(response);
40 |     return new Response(response.body, {
41 |       status: response.status,
42 |       statusText: response.statusText,
43 |       headers,
44 |     });
45 |   }
46 | 
47 |   const readme = await Deno.readTextFile("./README.md");
48 |   const body = render(readme);
49 |   const html = `<!DOCTYPE html>
50 |     <html lang="en">
51 |       <head>
52 |         <meta charset="UTF-8">
53 |         <meta name="viewport" content="width=device-width, initial-scale=1.0">
54 |         <title>CORS Proxy</title>
55 |         <style>
56 |           body {
57 |             margin: 0;
58 |             background-color: var(--color-canvas-default);
59 |             color: var(--color-fg-default);
60 |           }
61 |           main {
62 |             max-width: 800px;
63 |             margin: 0 auto;
64 |             padding: 2rem 1rem;
65 |           }
66 |           ${CSS}
67 |         </style>
68 |       </head>
69 |       <body data-color-mode="auto" data-light-theme="light" data-dark-theme="dark">
70 |         <main class="markdown-body">
71 |           ${body}
72 |         </main>
73 |       </body>
74 |     </html>`;
75 |   return new Response(html, {
76 |     headers: {
77 |       "content-type": "text/html;charset=utf-8",
78 |     },
79 |   });
80 | }
81 | 
82 | const port = Deno.env.get("PORT") ?? "8000";
83 | 
84 | serve(handleRequest, { port: Number(port) });
85 | 


--------------------------------------------------------------------------------