fix(proxy): allow empty string http_proxy env.

Close: #5380

Author: Hanaasagi

src/env_loader.zig

@@ -102,18 +102,24 @@ pub const Loader = struct {
 
         if (url.isHTTP()) {
             if (this.map.get("http_proxy") orelse this.map.get("HTTP_PROXY")) |proxy| {
-                if (proxy.len > 0) http_proxy = URL.parse(proxy);
+                if (proxy.len > 0 and !strings.eqlComptime(proxy, "\"\"") and !strings.eqlComptime(proxy, "''")) {
+                    http_proxy = URL.parse(proxy);
+                }
             }
         } else {
             if (this.map.get("https_proxy") orelse this.map.get("HTTPS_PROXY")) |proxy| {
-                if (proxy.len > 0) http_proxy = URL.parse(proxy);
+                if (proxy.len > 0 and !strings.eqlComptime(proxy, "\"\"") and !strings.eqlComptime(proxy, "''")) {
+                    http_proxy = URL.parse(proxy);
+                }
             }
         }
 
         // NO_PROXY filter
         if (http_proxy != null) {
             if (this.map.get("no_proxy") orelse this.map.get("NO_PROXY")) |no_proxy_text| {
-                if (no_proxy_text.len == 0) return http_proxy;
+                if (no_proxy_text.len == 0 or strings.eqlComptime(no_proxy_text, "\"\"") or strings.eqlComptime(no_proxy_text, "''")) {
+                    return http_proxy;
+                }
 
                 var no_proxy_list = std.mem.split(u8, no_proxy_text, ",");
                 var next = no_proxy_list.next();

test/js/bun/http/proxy.test.js

@@ -1,7 +1,9 @@
 import { afterAll, beforeAll, describe, expect, it } from "bun:test";
 import { gc } from "harness";
 import fs from "fs";
+import { tmpdir } from "os";
 import path from "path";
+import { bunExe } from "harness";
 
 let proxy, auth_proxy, server;
 
@@ -168,3 +170,30 @@ it("proxy non-TLS auth can fail", async () => {
     }
   }
 });
+
+it.each([
+  [undefined, undefined],
+  ["", ""],
+  ["''", "''"],
+  ['""', '""'],
+])("test proxy env, http_proxy=%s https_proxy=%s", async (http_proxy, https_proxy) => {
+  const path = `${tmpdir()}/bun-test-http-proxy-env-${Date.now()}.ts`;
+  fs.writeFileSync(path, 'await fetch("https://example.com");');
+
+  const { stdout, stderr, exitCode } = Bun.spawnSync({
+    cmd: [bunExe(), "run", path],
+    env: {
+      http_proxy: http_proxy,
+      https_proxy: https_proxy,
+    },
+    stdout: "pipe",
+    stderr: "pipe",
+  });
+
+  try {
+    expect(stderr.includes("FailedToOpenSocket: Was there a typo in the url or port?")).toBe(false);
+    expect(exitCode).toBe(0);
+  } finally {
+    fs.unlinkSync(path);
+  }
+});