Add test for normalized front matter

Author: senekor

front_matter/src/lib.rs

@@ -4,12 +4,13 @@ use serde::{Deserialize, Serialize};
 /// The front matter of a markdown blog post.
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 pub struct FrontMatter {
+    pub layout: String,
     pub title: String,
     pub author: String,
-    #[serde(default)]
-    pub release: bool,
+    pub description: Option<String>,
     pub team: Option<String>,
-    pub layout: String,
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub release: bool,
 }
 
 /// Extracts the front matter from a markdown file.
@@ -27,3 +28,78 @@ pub fn parse(markdown: &str) -> eyre::Result<(FrontMatter, &str)> {
 
     Ok((toml::from_str(front_matter)?, content))
 }
+
+/// Normalizes the front matter of a markdown file.
+pub fn normalize(markdown: &str) -> eyre::Result<String> {
+    let (front_matter, content) = parse(markdown)?;
+
+    Ok(format!(
+        "\
++++
+{}\
++++
+{content}",
+        toml::to_string_pretty(&front_matter)?
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{env, fs, path::PathBuf};
+
+    use super::*;
+
+    #[test]
+    fn front_matter_is_normalized() {
+        let repo_root = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("..");
+
+        let posts = fs::read_dir(repo_root.join("posts"))
+            .unwrap()
+            .chain(fs::read_dir(repo_root.join("posts/inside-rust")).unwrap())
+            .map(|p| p.unwrap().path())
+            .filter(|p| p.extension() == Some("md".as_ref()));
+
+        for post in posts {
+            let content = fs::read_to_string(&post).unwrap();
+            let normalized = normalize(&content).unwrap();
+
+            if content != normalized {
+                if env::var("FIX_FRONT_MATTER").is_ok() {
+                    fs::write(post, normalized).unwrap();
+                    continue;
+                }
+
+                let post = post.file_name().unwrap().to_str().unwrap();
+                let actual = content
+                    .rsplit_once("+++")
+                    .map(|(f, _)| format!("{f}+++"))
+                    .unwrap_or(content);
+                let expected = normalized
+                    .rsplit_once("+++")
+                    .map(|(f, _)| format!("{f}+++"))
+                    .unwrap_or(normalized);
+
+                // better error message than assert_eq!()
+                panic!(
+                    "
+The post {post} has abnormal front matter.
+
+    actual:
+{actual}
+
+    expected:
+{expected}
+
+    ┌──────────────────────────────────────────────────────────────────────────┐
+    │                                                                          │
+    │                You can fix this automatically by running:                │
+    │                                                                          │
+    │      FIX_FRONT_MATTER=1 cargo test --all front_matter_is_normalized      │
+    │                                                                          │
+    └──────────────────────────────────────────────────────────────────────────┘
+",
+                )
+            };
+        }
+    }
+}

src/posts.rs

@@ -50,6 +50,7 @@ impl Post {
                 release,
                 team: team_string,
                 layout,
+                ..
             },
             contents,
         ) = front_matter::parse(&contents)?;