From 70fe76209b79b5280fd6c5641ef5814e8fa5ee0d Mon Sep 17 00:00:00 2001
From: robobun <robobun@oven.sh>
Date: Sat, 24 Jan 2026 15:37:29 -0800
Subject: [PATCH] fix(readline): use symbol key for _refreshLine in tab
 completer (#26412)

---
 src/js/node/readline.ts             |  2 +-
 test/regression/issue/26411.test.ts | 40 +++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 test/regression/issue/26411.test.ts

diff --git a/src/js/node/readline.ts b/src/js/node/readline.ts
index 81328b378f..a66af032e6 100644
--- a/src/js/node/readline.ts
+++ b/src/js/node/readline.ts
@@ -1534,7 +1534,7 @@ var _Interface = class Interface extends InterfaceConstructor {
         prefix +
         StringPrototypeSlice.$call(this.line, this.cursor, this.line.length);
       this.cursor = this.cursor - completeOn.length + prefix.length;
-      this._refreshLine();
+      this[kRefreshLine]();
       return;
     }
 
diff --git a/test/regression/issue/26411.test.ts b/test/regression/issue/26411.test.ts
new file mode 100644
index 0000000000..37388ebb81
--- /dev/null
+++ b/test/regression/issue/26411.test.ts
@@ -0,0 +1,40 @@
+import { expect, test } from "bun:test";
+import { bunEnv, bunExe } from "harness";
+
+// https://github.com/oven-sh/bun/issues/26411
+// Tab completion with node:readline/promises threw
+// "TypeError: this._refreshLine is not a function"
+test("tab completion works with node:readline/promises", async () => {
+  await using proc = Bun.spawn({
+    cmd: [
+      bunExe(),
+      "-e",
+      `
+import readline from "node:readline/promises";
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout,
+  terminal: true,
+  completer: (line) => [["FOO", "FOOBAR"], line]
+});
+rl.line = "foo";
+rl.cursor = 3;
+setTimeout(() => {
+  rl.close();
+  console.log("OK");
+  process.exit(0);
+}, 100);
+rl.write("", { name: "tab" });
+`,
+    ],
+    env: bunEnv,
+    stdout: "pipe",
+    stderr: "pipe",
+  });
+
+  const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+  expect(stderr).not.toContain("this._refreshLine is not a function");
+  expect(stdout).toContain("OK");
+  expect(exitCode).toBe(0);
+});