Runtime control over which kinds of contract Bond evaluates.

Bond has two configuration layers:

• Compile-time — config :bond, <kind>: true | false | :purge (read via Application.compile_env/3), plus per-module :overrides and use Bond options. These are baked into each generated call site. :purge removes a kind's code entirely (zero runtime cost, not toggleable). See Bond for the full set of keys.

• Runtime — this module. enable/1, disable/1, and put/2 flip a kind on or off globally without recompiling. The state lives in a single :persistent_term entry read on every contracted call, so the gate stays cheap.

Kinds

:preconditions, :postconditions, :invariants, and :checks (for Bond.check/1,2).

How runtime and compile-time interact

On first use the runtime state is seeded from application env, so config :bond, … in both config.exs and config/runtime.exs is honoured. A kind with no global setting is :unset and falls back to the call site's compile-time default (including per-module :overrides). A value set here overrides that fallback until reset/0.

Runtime Application.put_env is not live

Setting Application.put_env(:bond, :preconditions, false) after the first contracted call has run has no effect — the runtime state is cached. Use disable/1 / enable/1, or call reset/0 to re-seed from current application env.

The chain

Bond enforces preconditions ≤ postconditions ≤ invariants: disabling a lower kind also skips the higher ones (with a one-time log). These setters are pure writes — they do not cascade; the chain is applied when contracts are evaluated. To turn everything off, disable :preconditions (or each kind explicitly).

Examples

# Disable precondition checks globally at runtime
Bond.Config.disable(:preconditions)

# Re-enable
Bond.Config.enable(:preconditions)

# Inspect the effective global state
Bond.Config.all()
#=> %{preconditions: false, postconditions: true, invariants: true, checks: true}

# Drop all runtime overrides, re-seeding from application env
Bond.Config.reset()

Performance note

Each put/2/enable/1/disable/1/reset/0 writes :persistent_term, which triggers a global GC scan. This is fine for setup and occasional toggles; do not toggle per call.