feat(fetch): add programmatic proxy (#10907)

This commit adds new options to unstable "Deno.createHttpClient" API.

"proxy" and "basicAuth" options were added that allow to use custom proxy
when client instance is passed to "fetch" API.

4 files changed, 59 insertions, 1 deletions

diff --git a/cli/dts/lib.deno.unstable.d.ts b/cli/dts/lib.deno.unstable.d.ts
index 828211c5b..1d01a748e 100644
--- a/cli/dts/lib.deno.unstable.d.ts
+++ b/cli/dts/lib.deno.unstable.d.ts
@@ -1089,6 +1089,17 @@ declare namespace Deno {
     /** A certificate authority to use when validating TLS certificates. Certificate data must be PEM encoded.
      */
     caData?: string;
+    proxy?: Proxy;
+  }
+
+  export interface Proxy {
+    url: string;
+    basicAuth?: BasicAuth;
+  }
+
+  export interface BasicAuth {
+    username: string;
+    password: string;
   }
 
   /** **UNSTABLE**: New API, yet to be vetted.
@@ -1096,7 +1107,12 @@ declare namespace Deno {
    *
    * ```ts
    * const client = Deno.createHttpClient({ caData: await Deno.readTextFile("./ca.pem") });
-   * const req = await fetch("https://myserver.com", { client });
+   * const response = await fetch("https://myserver.com", { client });
+   * ```
+   *
+   * ```ts
+   * const client = Deno.createHttpClient({ proxy: { url: "http://myproxy.com:8080" } });
+   * const response = await fetch("https://myserver.com", { client });
    * ```
    */
   export function createHttpClient(
diff --git a/cli/tests/045_programmatic_proxy_client.ts b/cli/tests/045_programmatic_proxy_client.ts
new file mode 100644
index 000000000..50884407d
--- /dev/null
+++ b/cli/tests/045_programmatic_proxy_client.ts
@@ -0,0 +1,16 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+const client = Deno.createHttpClient({
+  proxy: {
+    url: "http://localhost:4555",
+    basicAuth: { username: "username", password: "password" },
+  },
+});
+
+const res = await fetch(
+  "http://localhost:4545/test_util/std/examples/colors.ts",
+  { client },
+);
+console.log(`Response http: ${await res.text()}`);
+
+client.close();
diff --git a/cli/tests/045_proxy_test.ts b/cli/tests/045_proxy_test.ts
index c7ba5e967..6e338f4fc 100644
--- a/cli/tests/045_proxy_test.ts
+++ b/cli/tests/045_proxy_test.ts
@@ -15,6 +15,11 @@ async function proxyServer(): Promise<void> {
 
 async function proxyRequest(req: ServerRequest): Promise<void> {
   console.log(`Proxy request to: ${req.url}`);
+  const proxyAuthorization = req.headers.get("proxy-authorization");
+  if (proxyAuthorization) {
+    console.log(`proxy-authorization: ${proxyAuthorization}`);
+    req.headers.delete("proxy-authorization");
+  }
   const resp = await fetch(req.url, {
     method: req.method,
     headers: req.headers,
@@ -110,9 +115,28 @@ async function testModuleDownloadNoProxy(): Promise<void> {
   http.close();
 }
 
+async function testFetchProgrammaticProxy(): Promise<void> {
+  const c = Deno.run({
+    cmd: [
+      Deno.execPath(),
+      "run",
+      "--quiet",
+      "--reload",
+      "--allow-net=localhost:4545,localhost:4555",
+      "--unstable",
+      "045_programmatic_proxy_client.ts",
+    ],
+    stdout: "piped",
+  });
+  const status = await c.status();
+  assertEquals(status.code, 0);
+  c.close();
+}
+
 proxyServer();
 await testFetch();
 await testModuleDownload();
 await testFetchNoProxy();
 await testModuleDownloadNoProxy();
+await testFetchProgrammaticProxy();
 Deno.exit(0);
diff --git a/cli/tests/045_proxy_test.ts.out b/cli/tests/045_proxy_test.ts.out
index 4b07438ec..4957c9307 100644
--- a/cli/tests/045_proxy_test.ts.out
+++ b/cli/tests/045_proxy_test.ts.out
@@ -2,3 +2,5 @@ Proxy server listening on [WILDCARD]
 Proxy request to: http://localhost:4545/test_util/std/examples/colors.ts
 Proxy request to: http://localhost:4545/test_util/std/examples/colors.ts
 Proxy request to: http://localhost:4545/test_util/std/fmt/colors.ts
+Proxy request to: http://localhost:4545/test_util/std/examples/colors.ts
+proxy-authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ=