morph_edit uses Bun.file/Bun.write but OpenCode Desktop plugin runtime may not expose global Bun

[leytonblackler]

Summary

In OpenCode Desktop 1.17.12, the Morph OpenCode plugin morph_edit tool can fail with Bun is not defined because the plugin implementation reads/writes files through global Bun.file / Bun.write.

A minimal local compatibility patch replacing only that file I/O with Node fs/promises (readFile / writeFile) fixed the Desktop active-workflow smoke test while preserving the Morph SDK calls, tool names, WarpGrep tools, and compaction hooks.

Environment

• OpenCode Desktop: 1.17.12
• OpenCode CLI after alignment: 1.17.12
• Node: v24.16.0
• Plugin: @morphllm/opencode-morph-plugin@2.0.16
• Shell did not have a user-installed bun binary on PATH, but installing Bun alone is not expected to inject a global Bun into an Electron/Node plugin process.

Reproduction

1. Configure a valid MORPH_API_KEY for OpenCode Desktop.
2. Restart OpenCode Desktop.
3. Run morph_edit against an existing scratch file.

Observed error before patch:

Error reading file ...: Bun is not defined

Expected

morph_edit should work in OpenCode Desktop plugin runtimes that do not expose a global Bun, or the plugin/runtime requirement should be documented clearly.

Minimal fix tested locally

Replace the direct Bun file I/O calls in morph_edit with portable Node APIs:

import { readFile, writeFile } from "node:fs/promises";

originalCode = await readFile(filepath, "utf8");
await writeFile(filepath, normalizedCodeEdit, "utf8");
await writeFile(filepath, mergedCode, "utf8");

After this contained change was loaded as a local OpenCode plugin, Desktop active-workflow smoke tests passed for:

• existing-file morph_edit edit
• missing target file creation without lazy markers
• missing target file with lazy markers returning the expected safe error
• local WarpGrep
• public repo WarpGrep against vercel/next.js
• /morph compact slash-command interception

No Bun is not defined errors occurred after the patch.

Notes

This report is only about the OpenCode plugin Desktop compatibility surface. Generic Morph SDK/API usage is not the issue.