From 9497bf01933ff64cc8e9252117d02144c77063d2 Mon Sep 17 00:00:00 2001
From: Matthias <matthias-endler@gmx.net>
Date: Mon, 17 Jul 2023 13:15:41 +0200
Subject: [PATCH] Update docs

---
 lychee-lib/src/client.rs                 |  4 ++--
 lychee-lib/src/extract/markdown.rs       |  8 ++++---
 lychee-lib/src/utils/fragment_checker.rs | 29 +++++++++++++++++++-----
 3 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/lychee-lib/src/client.rs b/lychee-lib/src/client.rs
index d9d62ced22..b887235159 100644
--- a/lychee-lib/src/client.rs
+++ b/lychee-lib/src/client.rs
@@ -388,7 +388,7 @@ impl ClientBuilder {
             require_https: self.require_https,
             quirks,
             include_fragments: self.include_fragments,
-            fragment_checker: Default::default(),
+            fragment_checker: FragmentChecker::new(),
         })
     }
 }
@@ -687,7 +687,7 @@ impl Client {
 
     /// Checks a `file` URI's fragment.
     pub async fn check_fragment(&self, path: &Path, uri: &Uri) -> Status {
-        match self.fragment_checker.check(path, uri).await {
+        match self.fragment_checker.check(path, &uri.url).await {
             Ok(true) => Status::Ok(StatusCode::OK),
             Ok(false) => ErrorKind::InvalidFragment(uri.clone()).into(),
             Err(err) => {
diff --git a/lychee-lib/src/extract/markdown.rs b/lychee-lib/src/extract/markdown.rs
index 82bd243b9f..b5a0a751e7 100644
--- a/lychee-lib/src/extract/markdown.rs
+++ b/lychee-lib/src/extract/markdown.rs
@@ -99,11 +99,13 @@ pub(crate) fn extract_markdown_fragments(input: &str) -> HashSet<String> {
                     out.insert(frag.to_string());
                 }
 
-                let id = id_generator.generate(&mut heading);
-                out.insert(id);
+                if !heading.is_empty() {
+                    let id = id_generator.generate(&mut heading);
+                    out.insert(id);
+                    heading.clear();
+                }
 
                 in_heading = false;
-                heading.clear();
             }
             Event::Text(text) => {
                 if in_heading {
diff --git a/lychee-lib/src/utils/fragment_checker.rs b/lychee-lib/src/utils/fragment_checker.rs
index 13ddc72748..5b394c32b2 100644
--- a/lychee-lib/src/utils/fragment_checker.rs
+++ b/lychee-lib/src/utils/fragment_checker.rs
@@ -4,21 +4,39 @@ use std::{
     sync::Arc,
 };
 
-use crate::{extract::markdown::extract_markdown_fragments, types::FileType, Result, Uri};
+use crate::{extract::markdown::extract_markdown_fragments, types::FileType, Result};
 use tokio::{fs, sync::Mutex};
 use url::Url;
 
+/// Holds a cache of fragments for a given URL.
+///
+/// Fragments, also known as anchors, are used to link to a specific
+/// part of a page. For example, the URL `https://example.com#foo`
+/// will link to the element with the `id` of `foo`.
+///
+/// This cache is used to avoid having to re-parse the same file
+/// multiple times when checking if a given URL contains a fragment.
+///
+/// The cache is stored in a `HashMap` with the URL as the key and
+/// a `HashSet` of fragments as the value.
 #[derive(Default, Clone, Debug)]
 pub(crate) struct FragmentChecker {
     cache: Arc<Mutex<HashMap<String, HashSet<String>>>>,
 }
 
 impl FragmentChecker {
+    /// Creates a new `FragmentChecker`.
+    pub(crate) fn new() -> Self {
+        Self {
+            cache: Default::default(),
+        }
+    }
+
     /// Checks if the given path contains the given fragment.
-    pub(crate) async fn check(&self, path: &Path, uri: &Uri) -> Result<bool> {
-        match (FileType::from(path), uri.url.fragment()) {
+    pub(crate) async fn check(&self, path: &Path, url: &Url) -> Result<bool> {
+        match (FileType::from(path), url.fragment()) {
             (FileType::Markdown, Some(fragment)) => {
-                let url_without_frag = Self::remove_fragment(uri.url.clone());
+                let url_without_frag = Self::remove_fragment(url.clone());
                 self.populate_cache_if_vacant(url_without_frag, path, fragment)
                     .await
             }
@@ -26,8 +44,7 @@ impl FragmentChecker {
         }
     }
 
-    fn remove_fragment(url: Url) -> String {
-        let mut url = url;
+    fn remove_fragment(mut url: Url) -> String {
         url.set_fragment(None);
         url.into()
     }