drft/builders/
frontmatter.rs

1//! The `frontmatter` builder: emits link edges from frontmatter link-target
2//! values, plus the parsed frontmatter block as metadata on the file it read.
3//! It is colocated — its metadata is about its own file — so its drift rides the
4//! file's `fs` hash; it contributes no hash of its own.
5
6use globset::GlobSet;
7
8use crate::builders::link_edges;
9use crate::model::{Graph, Node};
10use crate::parsers::Parser;
11use crate::parsers::frontmatter::FrontmatterParser;
12
13/// Build the `frontmatter` graph fragment from text files, labeled `label`.
14/// `filter` scopes which paths the builder reads (`None` reads all); `keys`
15/// scopes which frontmatter keys yield edges (`None` uses shape detection). The
16/// fragment carries edges plus a node per file whose frontmatter parses to an
17/// object.
18pub fn build(
19    label: &str,
20    texts: &[(String, String)],
21    filter: Option<GlobSet>,
22    keys: Option<Vec<String>>,
23) -> Graph {
24    let parser = FrontmatterParser {
25        file_filter: filter,
26        keys,
27    };
28    let mut graph = Graph::labeled(label);
29
30    for (path, content) in texts {
31        if !parser.matches(path) {
32            continue;
33        }
34        let result = parser.parse(path, content);
35
36        if let Some(serde_json::Value::Object(block)) = result.metadata {
37            graph.set_node(path.clone(), Node::new(block));
38        }
39
40        for edge in link_edges(path, &result.links) {
41            graph.add_edge(edge);
42        }
43    }
44
45    graph.sort_edges();
46    graph
47}
48
49#[cfg(test)]
50mod tests {
51    use super::*;
52
53    fn texts(pairs: &[(&str, &str)]) -> Vec<(String, String)> {
54        pairs
55            .iter()
56            .map(|(p, c)| (p.to_string(), c.to_string()))
57            .collect()
58    }
59
60    #[test]
61    fn emits_metadata_and_edges() {
62        let t = texts(&[(
63            "analysis.md",
64            "---\ntitle: Analysis\nstatus: draft\nsources:\n  - ./data/notes.md\n---\n\n# Body\n",
65        )]);
66        let graph = build("frontmatter", &t, None, None);
67        assert_eq!(graph.label.as_deref(), Some("frontmatter"));
68
69        let meta = &graph.nodes["analysis.md"].metadata;
70        assert_eq!(meta["title"], serde_json::json!("Analysis"));
71        assert_eq!(meta["status"], serde_json::json!("draft"));
72
73        let targets: Vec<&str> = graph.edges.iter().map(|e| e.target.as_str()).collect();
74        assert_eq!(targets, vec!["data/notes.md"]);
75    }
76
77    #[test]
78    fn no_node_without_frontmatter() {
79        let t = texts(&[("plain.md", "# Just a heading\n")]);
80        let graph = build("frontmatter", &t, None, None);
81        assert!(graph.nodes.is_empty());
82        assert!(graph.edges.is_empty());
83    }
84}
drft/builders/frontmatter.rs

drft/builders/
frontmatter.rs
