test(go): check in mise's generated tables, so the emitter cannot drift unnoticed

[jdx]

The generator landed in #931 with snapshot tests over small fixtures, which prove it emits what it meant to and nothing about whether the result works. This is the other half: mise's committed spec, generated into go/internal/shadow/mise, checked in, and parsed against.

Checked in rather than built by the test, for the two reasons the Rust shadows are — a reviewer can read the diff when the emitter's vocabulary changes, and CI runs mise run gen-go and fails if regenerating produces one. A change to the generator that nobody meant now has to be committed rather than discovered later.

mise is the fixture because it is the largest usage CLI there is (211 commands, 711 flags, 128 positionals, four deep) and because every shape that has been awkward to express came from it. The cases are invocations out of its own docs, hand-written on purpose: what the generator produces is only worth checking if it parses the words users actually type.

Two properties measured at scale rather than at fixture size

Keys are unique and dense. Generated code dispatches on a Key, so two entries sharing one would bind the wrong field. The Rust derive hashes its way around this because two macro expansions cannot see each other; a generator sees the whole spec and can count, so a collision would be inexcusable rather than unlucky. Checked across all 989 entries.

A parse still allocates nothing. A scope lookup that collected flags into a slice, or a walk that built one per token, is invisible on a spec with four flags and obvious on one with 711. 110 ns and 0 allocations for mise use -g node@20.

One case pins a hole rather than a property

run --wat is unexpected_arg, because mise's spec gives run no positional at all — it clears them and adds mount run="mise tasks --usage", so task names come from running that, and binding does not resolve mounts. When mounts are answered that case changes, and pinning it means it changes loudly.

Also here

The README's conformance count was stale on main: #926 imported the argv questions clap's suite answers, taking the corpus from 123 vectors to 152. The Go parser answers all 122 binding vectors, up from 101, without a change — which is a better advertisement for the corpus than the original number was.

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Note

Low Risk
Mostly generated data, docs, CI, and tests; no runtime product behavior changes beyond guarding the Go emitter output.

Overview
Adds checked-in Go binding tables for mise’s full spec under go/internal/shadow/mise, regenerated via mise run gen-go (usage generate go on benches/mise.usage.kdl), mirroring the Rust shadow workflow so emitter changes show up in review and CI.

CI now runs gen-go and fails if render, gen-shadow, or gen-go leave a dirty tree.

Tests on the shadow tables cover real mise invocations, root default_subcommand run (not oci run), unique dense Keys across ~1000 entries, and zero allocations at full CLI scale (plus a benchmark). go/README.md documents //go:generate, the shadow package, updated corpus counts (122 binding / 30 post-binding skipped), and drops the generator from “what is missing.”

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[greptile-apps]

Greptile Summary

The PR checks in generated Go parser tables for mise and adds CI regeneration, semantic parsing, key-integrity, and allocation checks.

• Adds mise-scale generated Go command, flag, and argument tables.
• Tests representative command lines, default-subcommand resolution, key uniqueness and density, and zero-allocation parsing.
• Regenerates the tables in CI and fails when generation dirties the working tree.
• Documents Go table generation and updates conformance counts.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
.github/workflows/test.yml	Adds gen-go to the existing checked-in artifact regeneration guard.
go/README.md	Documents Go generation, checked-in mise tables, and current conformance coverage.
go/internal/shadow/mise/parse_test.go	Adds real-command parsing, default-subcommand, key-integrity, allocation, and benchmark coverage.
go/internal/shadow/mise/tables.go	Adds the generated mise parser table fixture with dense keys and the root-scoped default subcommand.
mise.toml	Defines deterministic regeneration of the checked-in mise Go tables.

_{Reviews (3): Last reviewed commit: "fix(go): regenerate mise's tables, and p..." | Re-trigger Greptile}

[github-actions]

Instruction counts

Nothing was compared, and so nothing was gated. No series appears on both sides: either the base has no measurements recorded, or the two were measured on different runner classes, which are deliberately not comparable — counts shift between machine types by more than a real regression does.

New, nothing to compare against: markdown on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1, startup on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1

_{Only instruction counts gate. Wall clock is shown for context — on identical hardware it moves 4-20% run to run.}

_{Measured by tak — instruction-counted CLI benchmarks, stored in this repository's git notes.}

Shadow comparison

Parsing mise use -g node@20 against a shadow of mise's committed spec.
Reported, not gated: the shadow grows as the derive learns to express more, so
what to watch is the ratio rather than either column.

	usage	clap	ratio
instructions, cold parse	71984	5893608	81x

usage: argv -> struct                            1247 ns      1.25 µs
clap: build tree + parse -> struct             511197 ns    511.20 µs
clap: parse -> struct, tree reused              23378 ns     23.38 µs
clap: build tree only                          315416 ns    315.42 µs

_{dcd3446e2d70 vs 25aa1535c847 · measured on the runner, not pushed to the history.}