Module fmt 

faucet fmt — canonicalize a pipeline config (#387).

A deterministic, idempotent config formatter — the config analogue of cargo fmt / terraform fmt. It parses the file, rewrites every object with a stable key order (a curated priority order for the well-known blocks, then alphabetical for everything else), and re-serializes it. Running fmt twice is always a no-op, so --check is a cheap CI gate for “is this config normalized?”.

Canonicalization is a pure serde_json::Value → serde_json::Value transform (canonicalize); the command layer only reads/writes files and renders the --check diff.

Scope: fmt formats the literal file — it does not resolve ${env:…} / ${file:…} interpolation, apply !include / extends composition, or drop schema defaults. Use faucet validate --show-composed to see the composed result.

Comments are not preserved — the config is parsed and re-serialized, the same limitation faucet migrate documents.

Functions

canonicalize

Rewrite value into canonical form: every object’s keys are reordered by (canonical rank, then name), recursively. Pure and idempotent — running it on its own output is a no-op. Relies on serde_json’s preserve_order feature (enabled workspace-wide) so the rebuilt insertion order survives serialization.

run

Execute the fmt subcommand.