On Windows, the console code page is shared by every process attached to the same console window. On Japanese Windows, a freshly opened cmd window starts at code page 932.

The garbled output of Bun piped to Bun, reported in bun#43660, is the tip of the iceberg. The root problem is that Bun changes the console code page while it runs. This project collects reproducible evidence of the harm that change causes, and files a Bun issue asking Bun not to change the code page, which also fixes bun#43660. Node.js and Deno are measured the same way for comparison.

Bun maintainers: start with Code page test results.

To run the same tests on any Windows PC after cloning (nothing installed on the PC is used):

1. Setup: download Bun, Bun canary, Node.js, Deno and pwsh into _bin\, then run npm ci: tools\10_setup\setup-runtimes.cmd
2. Test: run every test at code pages 932 and 437; the results go to research\evidence_last\: tools\40_test\run-tests.cmd
3. Compare: compare research\evidence_last\ with the committed research\evidence\: _bin\node\node tools\50_run\compare-evidence.ts

Plan

• Solving the Bun code page problem
• Issue bun#44693 (the posted text)

Research

• Code page test results
• Reproducing bun#43660

Project rules

• Local rules

Related issues

• oven-sh/bun#44693 — Bun switches the console code page to 65001 at startup (the root cause, filed from this project)
• oven-sh/bun#43660 — garbled output when piping Bun to Bun