bug(ENG-21479): Fix Valkey URL Parsing (#24458)

### What does this PR do?

Fixes https://github.com/oven-sh/bun/issues/24385

### How did you verify your code works?

Confirmed that the test added in the first commit fails on mainline
`bun` and is fixed in this PR.

---------

Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>

src/valkey/js_valkey.zig

@@ -274,16 +274,45 @@ pub const JSValkeyClient = struct {
         else
             bun.String.static("valkey://localhost:6379");
         defer url_str.deref();
+        var fallback_url_buf: [2048]u8 = undefined;
 
         // Parse and validate the URL using URL.zig's fromString which returns null for invalid URLs
-        const parsed_url = URL.fromString(url_str) orelse {
-            if (url_str.tag != .StaticZigString) {
-                const url_utf8 = url_str.toUTF8WithoutRef(this_allocator);
-                defer url_utf8.deinit();
-                return globalObject.throwInvalidArguments("Invalid URL format: \"{s}\"", .{url_utf8.slice()});
-            }
-            // This should never happen since our default URL is valid
+        // TODO(markovejnovic): The following check for :// is a stop-gap. It is my expectation
+        // that URL.fromString returns null if the protocol is not specified. This is not, in-fact,
+        // the case right now and I do not understand why. It will take some work in JSC to
+        // understand why this is happening, but since I need to uncork valkey, I'm adding this as
+        // a stop-gap.
+        const parsed_url = get_url: {
+            const url_slice = url_str.toUTF8WithoutRef(this_allocator);
+            defer url_slice.deinit();
+
+            const url_byte_slice = url_slice.slice();
+
+            if (url_byte_slice.len == 0) {
                 return globalObject.throwInvalidArguments("Invalid URL format", .{});
+            }
+
+            if (bun.strings.contains(url_byte_slice, "://")) {
+                break :get_url URL.fromString(url_str) orelse {
+                    return globalObject.throwInvalidArguments("Invalid URL format", .{});
+                };
+            }
+
+            const corrected_url = get_url_slice: {
+                const written = std.fmt.bufPrintZ(
+                    &fallback_url_buf,
+                    "valkey://{s}",
+                    .{url_byte_slice},
+                ) catch {
+                    return globalObject.throwInvalidArguments("URL is too long.", .{});
+                };
+
+                break :get_url_slice fallback_url_buf[0..written.len];
+            };
+
+            break :get_url URL.fromUTF8(corrected_url) orelse {
+                return globalObject.throwInvalidArguments("Invalid URL format", .{});
+            };
         };
         defer parsed_url.deinit();
 

test/_util/collection.ts

@@ -0,0 +1,11 @@
+/**
+ * Computes the Cartesian product of multiple arrays.
+ *
+ * @param arrays An array of arrays for which to compute the Cartesian product.
+ * @returns An array containing all combinations of elements from the input arrays.
+ */
+export function cartesianProduct<T, U>(left: T[], right: U[]): [T, U][] {
+  return left.flatMap(leftItem =>
+    right.map(rightItem => [leftItem, rightItem] as [T, U])
+  );
+}

test/regression/issue/24385.test.ts

@@ -0,0 +1,37 @@
+// https://github.com/oven-sh/bun/issues/24385
+// Test for Redis client import regression
+
+import { cartesianProduct } from "_util/collection";
+import { expect, test } from "bun:test";
+import { bunEnv, bunExe } from "harness";
+
+test.concurrent.each(
+  cartesianProduct(
+    ["REDIS_URL", "VALKEY_URL"],
+    [
+      "localhost:6379",
+      "redis+tls+unix:///tmp/redis.sock",
+      "redis+tls://localhost:6379",
+      "redis+unix:///tmp/redis.sock",
+      "redis://localhost:6379",
+      "rediss://localhost:6379",
+      "valkey://localhost:6379",
+    ],
+  ).map(([k, v]) => ({ key: k, value: v })),
+)("Redis loads with $key=$value", async ({ key, value }) => {
+  const env = { ...bunEnv, [key]: value };
+
+  await using proc = Bun.spawn({
+    // We need to call redis.duplicate() since Bun lazily imports redis.
+    cmd: [bunExe(), "-e", 'import { redis } from "bun"; const d = redis.duplicate(); console.log("success");'],
+    env,
+    stderr: "pipe",
+    stdout: "pipe",
+  });
+
+  const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+  expect(stderr).not.toContain("Expected url protocol to be one of");
+  expect(stdout).toContain("success");
+  expect(exitCode).toBe(0);
+});