feat: implement file: protocol support for fetch (#55)

* feat: export native fetch on the web

* chore: add file protocol support

* fix: cjs adapter

* feat: allow fetching file:// URLs

Author: Gozala

packages/fetch/package.json

@@ -100,6 +100,7 @@
     "@web-std/blob": "^3.0.3",
     "@web-std/form-data": "^3.0.2",
     "data-uri-to-buffer": "^3.0.1",
+    "mrmime": "^1.0.0",
     "@web3-storage/multipart-parser": "^1.0.0"
   },
   "esm": {

packages/fetch/src/fetch.js

@@ -9,6 +9,8 @@
 import http from 'http';
 import https from 'https';
 import zlib from 'zlib';
+import fs from 'fs';
+import * as mime from 'mrmime'
 import dataUriToBuffer from 'data-uri-to-buffer';
 
 import {writeToStream, fromAsyncIterable} from './body.js';
@@ -25,7 +27,7 @@ import { ReadableStream, Blob, FormData  } from './package.js';
 
 export {Headers, Request, Response, ReadableStream, Blob, FormData};
 
-const supportedSchemas = new Set(['data:', 'http:', 'https:']);
+const supportedSchemas = new Set(['data:', 'http:', 'https:', 'file:']);
 
 /**
  * Fetch function
@@ -50,6 +52,14 @@ async function fetch(url, options_ = {}) {
 			return;
 		}
 
+		if (options.protocol === 'file:') {
+			const stream = fs.createReadStream(new URL(request.url))
+			const type = mime.lookup(request.url) || 'application/octet-stream'
+			const response = new Response(stream, {headers: {'Content-Type': type }});
+			resolve(response);
+			return;
+		}
+
 		// Wrap http.request into fetch
 		const send = (options.protocol === 'https:' ? https : http).request;
 		const {signal} = request;

packages/fetch/test/file.js

@@ -0,0 +1,13 @@
+import fetch from '@web-std/fetch'
+import { assert } from "chai"
+describe("can fetch local files", () => {
+  it("can fetch local file", async () => {
+    const response = await fetch(import.meta.url)
+    assert.equal(response.headers.get('content-type'), "application/javascript")
+    const code = await response.text()
+
+    assert.ok(code.includes('it("can fetch local file"'))
+  })
+})
+
+

yarn.lock

@@ -324,7 +324,21 @@
   dependencies:
     defer-to-connect "^1.0.1"
 
-"@types/chai@^4.3.0":
+"@types/chai-as-promised@^7.1.5":
+  version "7.1.5"
+  resolved "https://registry.yarnpkg.com/@types/chai-as-promised/-/chai-as-promised-7.1.5.tgz#6e016811f6c7a64f2eed823191c3a6955094e255"
+  integrity sha512-jStwss93SITGBwt/niYrkf2C+/1KTeZCZl1LaeezTlqppAKeoQC7jxyqYuP72sxBGKCIbw7oHgbYssIRzT5FCQ==
+  dependencies:
+    "@types/chai" "*"
+
+"@types/chai-string@^1.4.2":
+  version "1.4.2"
+  resolved "https://registry.yarnpkg.com/@types/chai-string/-/chai-string-1.4.2.tgz#0f116504a666b6c6a3c42becf86634316c9a19ac"
+  integrity sha512-ld/1hV5qcPRGuwlPdvRfvM3Ka/iofOk2pH4VkasK4b1JJP1LjNmWWn0LsISf6RRzyhVOvs93rb9tM09e+UuF8Q==
+  dependencies:
+    "@types/chai" "*"
+
+"@types/chai@*", "@types/chai@^4.3.0":
   version "4.3.0"
   resolved "https://registry.yarnpkg.com/@types/chai/-/chai-4.3.0.tgz#23509ebc1fa32f1b4d50d6a66c4032d5b8eaabdc"
   integrity sha512-/ceqdqeRraGolFTcfoXNiqjyQhZzbINDngeoAq9GoHa8PPK1yNzTaxWjA6BFWp5Ua9JpXEMSS4s5i9tS0hOJtw==
@@ -4207,6 +4221,11 @@ mri@^1.1.0:
   resolved "https://registry.yarnpkg.com/mri/-/mri-1.2.0.tgz#6721480fec2a11a4889861115a48b6cbe7cc8f0b"
   integrity sha512-tzzskb3bG8LvYGFF/mDTpq3jpI6Q9wc3LEmBaghu+DdCssd1FakN7Bc0hVNmEyGq1bq3RgfkCb3cmQLpNPOroA==
 
+mrmime@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/mrmime/-/mrmime-1.0.0.tgz#14d387f0585a5233d291baba339b063752a2398b"
+  integrity sha512-a70zx7zFfVO7XpnQ2IX1Myh9yY4UYvfld/dikWRnsXxbyvMcfz+u6UfgNAtH+k2QqtJuzVpv6eLTx1G2+WKZbQ==
+
 ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"