Function assert_or_bless_output

tests/disas.rs:346–399

(path: &Path, wat: &str, actual: &str)

}

fn assert_or_bless_output(path: &Path, wat: &str, actual: &str) -> Result<()> {
    log::debug!("=== actual ===\n{actual}");
    // The test's expectation is the final comment.
    let mut expected_lines: Vec<_> = wat
        .lines()
        .rev()
        .map_while(|l| l.strip_prefix(";;"))
        .map(|l| l.strip_prefix(" ").unwrap_or(l))
        .collect();
    expected_lines.reverse();
    let expected = expected_lines.join("\n");
    let expected = expected.trim();
    log::debug!("=== expected ===\n{expected}");

    if actual == expected {
        return Ok(());
    }

    if std::env::var("WASMTIME_TEST_BLESS").unwrap_or_default() == "1" {
        let old_expectation_line_count = wat
            .lines()
            .rev()
            .take_while(|l| l.starts_with(";;"))
            .count();
        let old_wat_line_count = wat.lines().count();
        let new_wat_lines: Vec<_> = wat
            .lines()
            .take(old_wat_line_count - old_expectation_line_count)
            .map(|l| l.to_string())
            .chain(actual.lines().map(|l| {
                if l.is_empty() {
                    ";;".to_string()
                } else {
                    format!(";; {l}")
                }
            }))
            .collect();
        let mut new_wat = new_wat_lines.join("\n");
        new_wat.push('\n');
        std::fs::write(path, new_wat)
            .with_context(|| format!("failed to write file: {}", path.display()))?;
        return Ok(());
    }

    bail!(
        "Did not get the expected CLIF translation:\n\n\
         {}\n\n\
         Note: You can re-run with the `WASMTIME_TEST_BLESS=1` environment\n\
         variable set to update test expectations.",
        TextDiff::from_lines(expected, actual)
            .unified_diff()
            .header("expected", "actual")
    )
}