roundtrip-check

Roundtrip Check: Render → Adopt → Compare

Goal: prove that for every adapter where adopt.go claims a path is reversible, Render(canonical) → AdoptExternal(rendered_path) → reload canonical produces the same canonical entity bytes.

Procedure

Operate in a temp workspace — do not pollute examples/sandbox/ or the repo's .agentsync/.

1. Build a probe canonical

Create /tmp/agentsync-roundtrip/.agentsync/ with:

• AGENTS.md — non-trivial multi-line content with code fences and unicode.
• rules/sample-rule.md — frontmatter (description, paths: [src/**/*.ts]) + body.
• skills/sample-skill/SKILL.md — frontmatter with every field set (name, description, allowed-tools, disable-model-invocation: true, paths).
• agents/sample-agent.md — frontmatter (name, description, tools, model: sonnet) + body.
• commands/sample-command.md — frontmatter (description, argument-hint, allowed-tools, model) + body.

The reserved name general must not appear — it will fail load.

2. Render via every adapter for both scopes

Write a small Go test (or a go run-able script under scripts/) that:

c, _ := canonical.Load(tmpWorkspace)
for _, a := range tools.All() {
    for _, scope := range []tools.Scope{tools.ScopeProject, tools.ScopeUser} {
        if !a.SupportsScope(scope).Supported { continue }
        writes, _ := a.Render(c, scope)
        for _, fw := range writes {
            // write fw to disk under tmpWorkspace
        }
    }
}

3. Adopt every written path

For each fw.Path written above, call syncer.AdoptExternal(tmpWorkspace, fw.Path). Track which paths return errors — those are paths the adapter emits that adopt.go does not handle. Three valid outcomes:

• Adopted successfully — proceed to step 4.
• Adopted with the wrong canonical entity — bug in adopt.go matchers.
• Returns "no canonical mapping for path" — either expected (concatenated rule bodies, alias files like general.mdc → AGENTS.md) or a missing matcher. The adapter file should document which paths are intentionally non-reversible.