Highlights​

One call validates the whole spec tree​

Validate gains a validate_all method that runs a spec type's own rules and then descends into every #[confval(nested)] field, recursively.

A Validate impl covers one spec type's own fields, so reaching a nested block used to mean calling into it manually from the parent spec's Validate impl. Forgetting that call left the nested block unvalidated with nothing to indicate it.

spec.validate_all(&mut report);

The descent comes from #[derive(Spec)], so a nested block added later is validated without editing a validator. See Validation for the full picture.

Existing Validate impls do not change​

Validate::validate keeps its signature and stays the only method you have to write. validate_all and descend are provided methods, so an impl written against v0.4.0 compiles unchanged.

Added​

• Validate::validate_all, the entry point that runs a spec's rules and then its nested children.
• Validate::descend, which decides whether the children of a block are visited.
• ValidateNested, the traversal trait that #[derive(Spec)] implements for you.
• ControlFlow and ValidateNested in the prelude.
• A validate_traversal example.

Changed​

• #[derive(Spec)] now emits an impl ValidateNested alongside the impl FromFields. Nothing about the parser changed.
• The bound on every generated Lower impl moves from where S: Validate to where S: Validate + ValidateNested. A spec that derives Spec satisfies the second half automatically.
• A nested spec without a Validate impl is now a compile error at its parent rather than a block that is skipped.

Upgrading​

Replace the top level spec.validate(&mut report) with spec.validate_all(&mut report).

Delete any calls into child specs from your Validate impls.

A leftover call reports the child's issues twice, so it is worth a grep to find the calls and remove them:

grep -rn ".validate(" crates/ 

A spec with a handwritten FromFields has no derive to generate its traversal and needs its own impl ValidateNested. The lowering bound reports the missing impl.

[dependencies]
confval = { version = "0.5", features = ["derive", "hcl", "color"] }

Highlights​

Enforced Validate bound on specs​

A compiler error will occur if a spec does not implement the Validate trait. The trigger for this is lowering.

The compilation error will be similar to this, where the trait is not implemented for the example LimitsSpec. It materializes as an unsatisfied trait bound on #[derive(confval::Config)]:

error[E0277]: the trait bound `spec::LimitsSpec: confval::pipeline::Validate` is not satisfied
  --> crates/confval/examples/common/config.rs:21:10
   |
21 | #[derive(confval::Config)]
   |          ^^^^^^^^^^^^^^^ unsatisfied trait bound
   |
help: the trait `confval::pipeline::Validate` is not implemented for `spec::LimitsSpec`
  --> crates/confval/examples/common/spec.rs:23:1

To resolve such errors, implement the trait for the spec.

Unified workspace versioning​

confval and confval-derive are now versioned in lockstep through [workspace.package].

confval pins its derive crate with confval-derive = "=0.4.0", so a given confval always resolves the matching derive.

Changed​

• confval-derive moves from 0.1.1 to 0.4.0 to align with confval. This is a version-number change only. There is no change to the derive macro output or its public API.

Upgrading​

Depend on confval as before. The derive feature continues to pull in the matching confval-derive automatically.

[dependencies]
confval = { version = "0.4", features = ["derive", "hcl", "color"] }