Auto-generated Tests

For every non-template #[wgsl] module, the macro automatically generates a hidden test that validates the transpiled WGSL through naga. Running cargo test therefore validates every shader in the crate.

What Gets Generated

Given:

#![allow(unused)]
fn main() {
#[wgsl]
pub mod example {
    use wgsl_rs::std::*;
}
}

the macro emits (approximately):

#![allow(unused)]
fn main() {
#[test]
fn __validate_wgsl() {
    example::WGSL_SOURCE.validate().expect("WGSL validation failed");
}
}

The test name is fixed; there is one per #[wgsl] module. A failure prints the naga diagnostic and the failing module path.

Running the Tests

cargo test                          # validate every #[wgsl] module
cargo test example                  # narrow to one module
cargo test __validate_wgsl          # run only the auto-generated validation tests

A passing test means the generated WGSL parses and passes naga's type-check for the module's declared bindings, entry points, and function bodies.

Template Modules are Excluded

A template module (one with type-parameterized entry points or impl Trait linkages) emits WGSL containing TypeParam placeholders. That text is not valid WGSL on its own, so the macro does not generate an auto-test for templates.

To validate a template, supply concrete types via:

#![allow(unused)]
fn main() {
#[wgsl(validate_with_instantiation_types(f32, f32))]
pub mod hello_triangle_generic { /* ... */ }
}

The attribute makes the auto-test instantiate the template with the given types and validate the resulting concrete module. The number and order of types must match the template's declared type parameters.

See Runtime Validation for validating instantiated templates from your own code, and Templates for the broader template story.

Skipping a Single Module

If a specific module must opt out of auto-validation (e.g. it intentionally exercises a known transpiler bug, or it depends on an extension naga does not yet support), annotate it:

#![allow(unused)]
fn main() {
#[wgsl(skip_validation)]
pub mod example { /* ... */ }
}

No __validate_wgsl test is generated for that module. Other modules are unaffected. See Disabling Validation.