Fix bundling not using ascii_only

src/js_printer.zig

@@ -6036,7 +6036,8 @@ pub fn printWithWriterAndPlatform(
  comptime generate_source_maps: bool,
 ) PrintResult {
  const PrinterType = NewPrinter(
- false,
+ // if it's bun, it is also ascii_only
+ is_bun_platform,
  Writer,
  false,
  is_bun_platform,

test/regression/issue/09559.test.ts

@@ -0,0 +1,22 @@
+import { $ } from "bun";
+import { expect, test } from "bun:test";
+import { bunEnv, bunExe, tempDirWithFiles } from "harness";
+import { readdirSync } from "node:fs";
+import { join } from "path";
+
+test("bun build --target bun should support non-ascii source", async () => {
+ const files = {"index.js": `
+ console.log(JSON.stringify({我: "a"}));
+
+ const 我 = "b";
+ console.log(JSON.stringify({我}));
+ `};
+ const filenames = Object.keys(files);
+ const source = tempDirWithFiles("source", files);
+
+ $.throws(true);
+ await $`${bunExe()} build --target bun ${join(source, "index.js")} --outfile ${join(source, "bundle.js")}`;
+ const result = await $`${bunExe()} ${join(source, "bundle.js")}`.text();
+
+ expect(result).toBe(`{"我":"a"}\n{"我":"b"}\n`);
+})