From 29bc107c97c584e628e349c084fb7a4eba7add15 Mon Sep 17 00:00:00 2001
From: Osama Ansar <osama.ansar.pk@gmail.com>
Date: Fri, 4 Sep 2026 13:21:41 +0500
Subject: [PATCH] fix(uri): keep a trailing slash on the base URL so proxied
 sub-paths survive

`encodeBaseUrl` returned a base URL whose path had no trailing slash
(e.g. `https://host/db/prod`). The Hrana client resolves endpoint paths
against it with `new URL("v2/pipeline", baseUrl)`, and per the WHATWG URL
resolver that replaces the last path segment when the base does not end
in `/`. So a client pointed at a libSQL server behind a reverse proxy on
a sub-path sent every request one segment short
(`https://host/db/v2/pipeline` instead of `https://host/db/prod/v2/pipeline`),
which is why appending a `/` to the URL was the known workaround.

Append a trailing slash to a non-empty path in `encodeBaseUrl` so the
base URL is safe for relative resolution. The root case (`""` / `"/"`)
is unchanged. The `wss:`/`ws:` clients get the same normalized URL; the
Hrana WebSocket handshake is not sensitive to the trailing slash.

Closes #296
---
 .../libsql-client/src/__tests__/uri.test.ts   | 30 +++++++++++++++++--
 packages/libsql-core/src/uri.ts               |  7 +++++
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/packages/libsql-client/src/__tests__/uri.test.ts b/packages/libsql-client/src/__tests__/uri.test.ts
index 6ea18b62..71dc2f91 100644
--- a/packages/libsql-client/src/__tests__/uri.test.ts
+++ b/packages/libsql-client/src/__tests__/uri.test.ts
@@ -216,13 +216,13 @@ test("encodeBaseUrl()", () => {
             scheme: "http",
             host: "localhost",
             path: "/foo/bar",
-            url: "http://localhost/foo/bar",
+            url: "http://localhost/foo/bar/",
         },
         {
             scheme: "http",
             host: "localhost",
             path: "foo/bar",
-            url: "http://localhost/foo/bar",
+            url: "http://localhost/foo/bar/",
         },
         {
             scheme: "http",
@@ -262,7 +262,7 @@ test("encodeBaseUrl()", () => {
             userinfo: { username: "alice", password: "secret" },
             port: 8080,
             path: "/some/path",
-            url: "https://alice:secret@localhost:8080/some/path",
+            url: "https://alice:secret@localhost:8080/some/path/",
         },
     ];
 
@@ -272,3 +272,27 @@ test("encodeBaseUrl()", () => {
         ).toStrictEqual(new URL(url));
     }
 });
+
+test("encodeBaseUrl() keeps the full path when the Hrana client resolves an endpoint against it", () => {
+    // Regression for #296: a deployment proxied under a sub-path lost its last
+    // path segment because `new URL("v2/pipeline", base)` drops it unless the
+    // base path ends with "/".
+    const authority = {
+        host: "example.com",
+        port: undefined,
+        userinfo: undefined,
+    };
+
+    const base = encodeBaseUrl("https", authority, "/some/sub/path");
+    expect(new URL("v2/pipeline", base).href).toBe(
+        "https://example.com/some/sub/path/v2/pipeline",
+    );
+    expect(new URL("v3-protobuf/pipeline", base).href).toBe(
+        "https://example.com/some/sub/path/v3-protobuf/pipeline",
+    );
+
+    const root = encodeBaseUrl("https", authority, "");
+    expect(new URL("v2/pipeline", root).href).toBe(
+        "https://example.com/v2/pipeline",
+    );
+});
diff --git a/packages/libsql-core/src/uri.ts b/packages/libsql-core/src/uri.ts
index 470df4ef..203ee5dd 100644
--- a/packages/libsql-core/src/uri.ts
+++ b/packages/libsql-core/src/uri.ts
@@ -176,6 +176,13 @@ export function encodeBaseUrl(
     if (pathText !== "" && !pathText.startsWith("/")) {
         pathText = "/" + pathText;
     }
+    // The Hrana client resolves endpoint paths ("v2/pipeline", ...) against this
+    // URL with `new URL(endpointPath, baseUrl)`, which replaces the last path
+    // segment unless the base path ends with "/". Keep the trailing slash so a
+    // deployment served under a proxied sub-path does not lose that segment.
+    if (pathText !== "" && !pathText.endsWith("/")) {
+        pathText += "/";
+    }
 
     return new URL(`${schemeText}${authorityText}${pathText}`);
 }