codemode: TextEncoder.encode(null) silently returns empty bytes #57632

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1. opencode-agent commented on Oct 21, 2026

   

   opencode-agentBot

   on Oct 21, 2026 – with OpenCode Agent

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   Thanks for the clear report. I reproduced this on the latest dev (c9b5a9f, @opencode/codemode 2.1.2). Inside Code Mode, new TextEncoder().encode(null) returns [], but native TextEncoder returns [110, 117, 108, 108]. encode() and encode(undefined) correctly return []. As you found, the cause looks like the args[0] ?? "" in packages/codemode/src/stdlib/bytes.ts, which turns an explicit null into an empty string. The script below reproduces it.

   Reproduction script (repro.ts)

   // Run from an opencode checkout: bun /workspace/repro/repro.ts [/path/to/repo]
   import { Effect } from "effect"
   const repo = process.argv[2] ?? process.env.OC_DEV ?? "/workspace/repo"
   const { CodeMode } = await import(`${repo}/packages/codemode/src/index.ts`)
   
   for (const code of [
     "return [...new TextEncoder().encode(null)]",
     "return [...new TextEncoder().encode()]",
     "return [...new TextEncoder().encode(undefined)]",
   ]) {
     const r = await Effect.runPromise(CodeMode.execute({ code, tools: {} }))
     console.log(code, "=>", JSON.stringify(r.value ?? r))
   }
   const native = (v: any) => [...new TextEncoder().encode(v)]
   console.log("native null =>", JSON.stringify(native(null)), " native undefined =>", JSON.stringify(native(undefined)))

   Run it: bun repro.ts
2. opencode-agent

   added

   reproduced

   on Oct 21, 2026
3. sdivyanshu90 commented on Oct 21, 2026

   

   sdivyanshu90

   on Oct 21, 2026

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   Hi @rekram1-node, I'd like to claim this issue. I've prepared a fix with regression tests: encode(null) preserves the text "null", while omitted input and undefined still produce empty bytes. The full CodeMode suite and package typecheck pass.

   Could you please review the proposed fix when you have some time? I can raise a PR, but GitHub currently blocks creation with: "You've reached this repository's open pull request limit." I'll open it once a slot is available. Thanks!
4. rekram1-node commented on Oct 21, 2026

   

   rekram1-node

   on Oct 21, 2026

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   im not looking to endlessly make the interpreter handle every edge case in javascript, it's a tool orchestration environment, unless ur seeing agents write code that breaks then i dont rlly want more of these styles of issues opened ideally

   Not sure if u actually hit this or if u just have agents looking to find issues, but this seems like edge case

   👍React with 👍1Reacted by Divanshu
5. sdivyanshu90 commented on Oct 21, 2026

   

   sdivyanshu90

   on Oct 21, 2026

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   Thanks for clarifying, @rekram1-node. These reports came from compatibility testing, not failures I encountered in an actual agent workflow. I should have made that distinction clear.

   I’ll leave #57633 closed, and I’m happy to close #57632 as well. Going forward, I’ll focus on issues with demonstrated impact on real V2 workflows. Thanks for the guidance.

   👍React with 👍1Reacted by Aiden Cline
6. rekram1-node commented on Oct 21, 2026

   

   rekram1-node

   on Oct 21, 2026

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   sounds good ill close this for now then thanks.

   Ideally don't look for issues, instead raise problems u actually hit. Otherwise it's a lot of noise for us.
7. rekram1-node

   closed this as not plannedon Oct 21, 2026