From a3dba9a8bfb2135c511c1b2510e95908891657b0 Mon Sep 17 00:00:00 2001
From: Mads Hougesen <mads@mhouge.dk>
Date: Mon, 11 Mar 2024 14:28:35 +0100
Subject: [PATCH] feat: ignore frontmatter

---
 Cargo.lock           | 29 +++++++++++++++++++++++++++++
 Cargo.toml           |  1 +
 src/lib.rs           | 13 ++++++++++++-
 tests/frontmatter.md | 19 +++++++++++++++++++
 4 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 tests/frontmatter.md

diff --git a/Cargo.lock b/Cargo.lock
index 9a703fc9..69966c31 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -215,6 +215,12 @@ version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1a46d1a171d865aa5f83f92695765caa047a9b4cbae2cbf37dbd613a793fd4c"
 
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.153"
@@ -233,12 +239,23 @@ version = "0.4.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
 
+[[package]]
+name = "matter"
+version = "0.1.0-alpha4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc16e839c57e0ad77957c42d39baab3692a1c6fa47692066470cddc24a5b0cd0"
+dependencies = [
+ "lazy_static",
+ "regex",
+]
+
 [[package]]
 name = "mdsf"
 version = "0.0.0"
 dependencies = [
  "clap",
  "ignore",
+ "matter",
  "pulldown-cmark",
  "pulldown-cmark-to-cmark",
  "schemars",
@@ -291,6 +308,18 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b62dbe01f0b06f9d8dc7d49e05a0785f153b00b2c227856282f671e0318c9b15"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
 [[package]]
 name = "regex-automata"
 version = "0.4.6"
diff --git a/Cargo.toml b/Cargo.toml
index f55c508c..a9bf2662 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,7 @@ categories = ["development-tools"]
 [dependencies]
 clap = { version = "4.5.2", features = ["derive"] }
 ignore = "0.4.22"
+matter = "0.1.0-alpha4"
 pulldown-cmark = { version = "0.9.6", default-features = false }
 pulldown-cmark-to-cmark = "11.2.0"
 schemars = "0.8.16"
diff --git a/src/lib.rs b/src/lib.rs
index e4f9603c..e06438e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,6 +2,7 @@ use config::MdsfConfig;
 use error::MdsfError;
 use formatters::format_snippet;
 use languages::Language;
+use matter::matter;
 use pulldown_cmark::CowStr;
 use pulldown_cmark_to_cmark::cmark_resume_with_options;
 
@@ -48,7 +49,11 @@ pub fn format_file(config: &MdsfConfig, path: &std::path::Path) -> Result<(), Md
         return Ok(());
     }
 
-    let parser = pulldown_cmark::Parser::new_ext(&input, pulldown_cmark::Options::all());
+    // NOTE: should be removed once `pulldown-cmark-to-cmark` is upgraded to `v0.10.0` of `pulldown-cmark`
+    let (frontmatter, markdown_input) =
+        matter(&input).unwrap_or_else(|| (String::new(), input.to_owned()));
+
+    let parser = pulldown_cmark::Parser::new_ext(&markdown_input, pulldown_cmark::Options::all());
 
     let mut output = String::with_capacity(input.len() + 128);
 
@@ -105,6 +110,12 @@ pub fn format_file(config: &MdsfConfig, path: &std::path::Path) -> Result<(), Md
         s.finalize(&mut output).map_err(MdsfError::from)?;
     }
 
+    output = output.trim().to_owned();
+
+    if !frontmatter.is_empty() {
+        output = format!("---\n{frontmatter}\n---\n\n{output}");
+    }
+
     if config.markdown.enabled {
         if !output.is_empty() {
             output = format_snippet(config, &Language::Markdown, &output);
diff --git a/tests/frontmatter.md b/tests/frontmatter.md
new file mode 100644
index 00000000..99fb24e7
--- /dev/null
+++ b/tests/frontmatter.md
@@ -0,0 +1,19 @@
+---
+tile1: asd asd
+tile2: asd asd
+tile3: asd asd
+
+tile4: asd asd
+
+tile5: asd asd
+---
+
+this is the content
+
+```go
+package main
+
+func add(a int, b int) int {
+	return a + b
+}
+```