Files
simple-rust-tests/__wasm/wit-bindgen-sample/wit-bindgen/crates/wit-component/tests/roundtrip.rs

64 lines
2.1 KiB
Rust

use anyhow::{Context, Result};
use pretty_assertions::assert_eq;
use std::fs;
use wit_component::{decode_interface_component, InterfaceEncoder, InterfacePrinter};
use wit_parser::Interface;
/// Tests the the roundtrip encoding of individual interface files.
///
/// This test looks in the `interfaces/` directory for test cases.
///
/// Each test case is a directory containing a `<testcase>.wit` file.
///
/// The test encodes the wit file, decodes the resulting bytes, and
/// compares the generated interface definition to the original interface
/// definition.
///
/// Run the test with the environment variable `BLESS` set to update
/// the wit file based on the decoded output.
#[test]
fn roundtrip_interfaces() -> Result<()> {
for entry in fs::read_dir("tests/interfaces")? {
let path = entry?.path();
if !path.is_dir() {
continue;
}
let test_case = path.file_stem().unwrap().to_str().unwrap();
let wit_path = path.join(test_case).with_extension("wit");
let interface = Interface::parse_file(&wit_path).context("failed to parse `wit` file")?;
let encoder = InterfaceEncoder::new(&interface).validate(true);
let bytes = encoder.encode().with_context(|| {
format!(
"failed to encode a component from interface `{}` for test case `{}`",
path.display(),
test_case,
)
})?;
let interface = decode_interface_component(&bytes).context("failed to decode bytes")?;
let mut printer = InterfacePrinter::default();
let output = printer
.print(&interface)
.context("failed to print interface")?;
if std::env::var_os("BLESS").is_some() {
fs::write(&wit_path, output)?;
} else {
assert_eq!(
fs::read_to_string(&wit_path)?.replace("\r\n", "\n"),
output,
"encoding of wit file `{}` did not match the the decoded interface for test case `{}`",
wit_path.display(),
test_case,
);
}
}
Ok(())
}