Fix segfault on passing undefined to bun.build (#2902)

2 files changed, 15 insertions, 0 deletions

diff --git a/src/bun.js/api/JSBundler.zig b/src/bun.js/api/JSBundler.zig
index c95c359f1..741d956bf 100644
--- a/src/bun.js/api/JSBundler.zig
+++ b/src/bun.js/api/JSBundler.zig
@@ -494,6 +494,11 @@ pub const JSBundler = struct {
         globalThis: *JSC.JSGlobalObject,
         arguments: []const JSC.JSValue,
     ) JSC.JSValue {
+        if (arguments.len == 0 or !arguments[0].isObject()) {
+            globalThis.throwInvalidArguments("Expected a config object to be passed to Bun.build", .{});
+            return JSC.JSValue.jsUndefined();
+        }
+
         var plugins: ?*Plugin = null;
         const config = Config.fromJS(globalThis, arguments[0], &plugins, globalThis.allocator()) catch {
             return JSC.JSValue.jsUndefined();
diff --git a/test/bundler/build.test.ts b/test/bundler/build.test.ts
index 054f24bc3..921481a4b 100644
--- a/test/bundler/build.test.ts
+++ b/test/bundler/build.test.ts
@@ -4,6 +4,16 @@ import { bunEnv, bunExe } from "harness";
 import { join } from "path";
 
 describe("Bun.build", () => {
+  test("passing undefined doesnt segfault", () => {
+    try {
+      // @ts-ignore
+      Bun.build();
+    } catch (error) {
+      return;
+    }
+    throw new Error("should have thrown");
+  });
+
   test("invalid options throws", async () => {
     expect(() => Bun.build({} as any)).toThrow();
     expect(() =>