harness-starter-coding

Harness Starter: Coding

A coding-assistant starter. Produces a unified-diff file as its primary deliverable plus a preview artifact listing the changed files. Copy this crate when you want to build an app that ships a patch/diff/changeset.

What this starter demonstrates

• primary = "patches/*.diff" — the canonical deliverable.
• preview = "patches/*.files.txt" — a secondary artifact the operator surface may use to summarize the change.
• file_size_min:$primary:64 — validator rejects empty patches.
• Multi-artifact spawn task binding (artifacts = ["primary", "preview"]) so the runtime delivers both files.

See docs/OCTOS_HARNESS_DEVELOPER_GUIDE.md for the full contract.

Tools

propose_patch

Render a patch as a unified-diff file plus a preview file list.

{
  "title": "Fix typo in hello",
  "hunks": [
    {
      "file": "src/lib.rs",
      "new_content": "pub fn hello() -> &'static str {\n    \"hi\"\n}\n"
    }
  ]
}

Parameters:

• title (required): short title; derives the filename (patches/fix-typo-in-hello.diff).
• hunks (required, non-empty): list of {file, new_content} hunks. Each hunk becomes a full-file replacement hunk in the diff.

Artifacts:

• patches/<slug>.diff — primary unified-diff file.
• patches/<slug>.files.txt — preview list of changed files.

Replace this stub

The starter generates full-file replacement hunks. A real coding assistant should use similar or diff to compute minimized unified diffs, and consider running the patch through git apply --check in a validator before delivery.