Crate fn_fixture 

This crate provides a procedural macro to set up tests based on a directory of inputs to a function.

A more complete explanation is provided in the readme of the repository.

Overview

The annotation has 3 primary requirements:

• It must be annotating a function with return type implementing std::fmt::Debug. Result is weakly recommended.

• It must use a string literal containing the path (relative to cargo manifest) to a base folder. A base folder must contain test folders or base folders. Test folders must contain exactly one of input.rs, input.txt, or input.bin.

• It must have a single parameter of the corresponding to a respective type of the input files as included by their respective macros, include, include_str, and include_bytes.

Example

project_root/src/lib/tests.rs

#[fn_fixture::snapshot("snapshot-tests/examples")]
fn parse_unsigned_number(value: &str) -> Result<usize, impl std::fmt::Debug> {
    value.parse()
}

project_root/snapshot-tests/examples/good_number/input.txt

42

Notice that snapshot-tests/examples does not itself contain an input.txt

Attribute Macros

snapshot

Denotes the entrance point of a function-fixture’s snapshots.