Method deserialize_lang_config

crates/test/src/lib.rs:1354–1376

Helper to convert `RuntimeTestConfig` to a `RuntimeTestConfig ` and then extract the `T`. This is called from within each language's implementation with a specific `T` necessary for that language.

(&self)

    /// This is called from within each language's implementation with a
    /// specific `T` necessary for that language.
    fn deserialize_lang_config<T>(&self) -> Result<T>
    where
        T: Default + serde::de::DeserializeOwned,
    {
        // If this test has no language-specific configuration then return this
        // language's default configuration.
        if self.lang_config.is_none() {
            return Ok(T::default());
        }

        // Otherwise re-parse the TOML at the top of the file but this time
        // with the specific `T` that we're interested in. This is expected
        // to then produce a value in the `lang` field since
        // `self.lang_config.is_some()` is true.
        let config = config::parse_test_config::<config::RuntimeTestConfig<T>>(
            &self.contents,
            self.language
                .obj()
                .comment_prefix_for_test_config()
                .unwrap(),
        )?;
        Ok(config.lang.unwrap())
    }
}