hyperlit-model 0.1.0

use hyperlit_base::result::HyperlitResult;
use hyperlit_base::{bail, err};

#[derive(Debug, PartialEq)]
pub enum Directive {
    IncludeByTag { tag: String },
    IncludeRest,
}

pub fn parse_directive(directive_string: &str) -> HyperlitResult<Directive> {
    let directive_string = directive_string
        .trim()
        .strip_prefix("§{")
        .ok_or_else(|| {
            err!(
                "Directive must start with '§{{', but was '{}'",
                directive_string
            )
        })?
        .strip_suffix("}")
        .ok_or_else(|| {
            err!(
                "Directive must end with '}}', but was '{}'",
                directive_string
            )
        })?;
    let directive_string = directive_string.trim();
    Ok(
        if let Some(tag) = directive_string.strip_prefix("@include_by_tag:") {
            let tag = tag.trim();
            let tag = tag.strip_prefix("#").unwrap_or(tag);
            Directive::IncludeByTag {
                tag: tag.to_string(),
            }
        } else if directive_string == "@include_rest" {
            Directive::IncludeRest
        } else {
            bail!("Unknown directive: '{}'", directive_string);
        },
    )
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_parse_include_by_tag() {
        assert_eq!(
            parse_directive("§{@include_by_tag: #the_tag}").unwrap(),
            Directive::IncludeByTag {
                tag: "the_tag".to_string()
            }
        );
    }

    #[test]
    fn test_parse_include() {
        assert_eq!(
            parse_directive("§{@include_rest}").unwrap(),
            Directive::IncludeRest,
        );
    }

    #[test]
    fn test_parse_other() {
        assert_eq!(
            parse_directive("foobar").unwrap_err().to_string(),
            "Directive must start with '§{', but was 'foobar'"
        );
    }
}