Use github-slugger in place of slug

.gitignore

@@ -7,3 +7,6 @@
 
 # Tarpaulin (https://github.com/xd009642/tarpaulin) HTML coverage report
 tarpaulin-report.html
+
+# This is autogenerated and does not need to be tracked by version control
+Cargo.lock

CONTRIBUTING.md

@@ -79,4 +79,9 @@ If you don't feel comfortable writing user documentation, I will be happy to gui
 ## Release notes
 
 [Towncrier](https://towncrier.readthedocs.io/en/stable/index.html) is used to generate release notes.
-If you add a changelog fragment to the `changelog.d` directory with `just add-changelog` (requires [just](https://github.com/casey/just#installation)) it will automatically be picked up when a new release is made.
+
+If you add a changelog fragment to the `changelog.d` directory with `just add-changelog`, it will automatically be picked up when a new release is made.
+
+This requires
+- [just](https://github.com/casey/just#installation)
+- [uv](https://github.com/astral-sh/uv)

Cargo.toml

@@ -35,7 +35,7 @@ pulldown-cmark-to-cmark = "21.0.0"
 rayon = "1.10.0"
 regex = "1.10.5"
 serde_yaml = "0.9.34"
-slug = "0.1.5"
+github-slugger = "0.1.0"
 snafu = "0.8.3"
 unicode-normalization = "0.1.23"
 filetime = "0.2.23"

changelog.d/370.fix.md

@@ -0,0 +1,3 @@
+Fixed header id links being non-compliant with github and gitlab markdown viewers.
+
+This allows links to heading anchors to follow under github and gitlab.

src/lib.rs

@@ -17,13 +17,13 @@ pub use context::Context;
 use filetime::set_file_mtime;
 use frontmatter::{frontmatter_from_str, frontmatter_to_str};
 pub use frontmatter::{Frontmatter, FrontmatterStrategy};
+use github_slugger::slug;
 use pathdiff::diff_paths;
 use percent_encoding::{utf8_percent_encode, AsciiSet, CONTROLS};
 use pulldown_cmark::{CodeBlockKind, CowStr, Event, HeadingLevel, Options, Parser, Tag, TagEnd};
 use pulldown_cmark_to_cmark::cmark_with_options;
 use rayon::prelude::*;
 use references::{ObsidianNoteReference, RefParser, RefParserState, RefType};
-use slug::slugify;
 use snafu::{ResultExt, Snafu};
 use unicode_normalization::UnicodeNormalization;
 pub use walker::{vault_contents, WalkOptions};
@@ -780,7 +780,7 @@ impl<'a> Exporter<'a> {
 
         if let Some(section) = reference.section {
             link.push('#');
-            link.push_str(&slugify(section));
+            link.push_str(&slug(section));
         }
 
         let link_tag = Tag::Link {

tests/export_test.rs

@@ -459,3 +459,26 @@ fn test_same_filename_different_directories() {
     let actual = read_to_string(tmp_dir.path().join(PathBuf::from("Note.md"))).unwrap();
     assert_eq!(expected, actual);
 }
+
+#[test]
+fn test_github_flavored_markdown_heading_id_compliance() {
+    let tmp_dir = TempDir::new().expect("failed to make tempdir");
+
+    Exporter::new(
+        PathBuf::from("tests/testdata/input/gfm-heading-ids-compliance"),
+        tmp_dir.path().to_path_buf(),
+    )
+    .run()
+    .unwrap();
+
+    let expected = if cfg!(windows) {
+        read_to_string("tests/testdata/expected/gfm-heading-ids-compliance/Note.md")
+            .unwrap()
+            .replace('/', "\\")
+    } else {
+        read_to_string("tests/testdata/expected/gfm-heading-ids-compliance/Note.md").unwrap()
+    };
+
+    let actual = read_to_string(tmp_dir.path().join(PathBuf::from("Note.md"))).unwrap();
+    assert_eq!(expected, actual);
+}

tests/testdata/expected/gfm-heading-ids-compliance/Note.md

@@ -0,0 +1,13 @@
+[A.B.C.D](Note.md#abcd)
+[with a name](Note.md#abcd)
+[1.2.3.4](Note.md#1234)
+[this-or-that](Note.md#this-or-that)
+[this--or-that](Note.md#this--or-that)
+
+# A.B.C.D
+
+# 1.2.3.4
+
+# this-or-that
+
+# this--or-that

tests/testdata/input/gfm-heading-ids-compliance/Note.md

@@ -0,0 +1,10 @@
+[[#A.B.C.D]]
+[[#A.B.C.D|with a name]]
+[[#1.2.3.4]]
+[[#this-or-that]]
+[[#this--or-that]]
+
+# A.B.C.D
+# 1.2.3.4
+# this-or-that
+# this--or-that