fix: only one of each attribute per HTML element

Sponsored-by: author

1 files changed, 34 insertions, 2 deletions

diff --git a/src/html.rs b/src/html.rs
index 2562b9b..3232724 100644
--- a/src/html.rs
+++ b/src/html.rs
@@ -7,6 +7,7 @@ use line_col::LineColLookup;
 use log::{debug, trace};
 use pulldown_cmark::{CodeBlockKind, Event, HeadingLevel, Options, Parser, Tag};
 use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
 use std::fmt::Write as _;
 use std::io::Write;
 use std::path::{Path, PathBuf};
@@ -381,9 +382,14 @@ impl Element {
     }
 
     fn serialize_attrs_to_buf(&self, buf: &mut String) -> Result<(), std::fmt::Error> {
+        let mut attrs = Attributes::default();
         for attr in self.attrs.iter() {
-            write!(buf, " {}", attr.name())?;
-            if let Some(value) = attr.value() {
+            attrs.push(attr);
+        }
+
+        for (name, value) in attrs.iter() {
+            write!(buf, " {}", name)?;
+            if !value.is_empty() {
                 write!(buf, "=\"{}\"", encode_double_quoted_attribute(value))?;
             }
         }
@@ -492,6 +498,32 @@ impl ElementTag {
     }
 }
 
+#[derive(Debug, Default, Clone)]
+struct Attributes {
+    attrs: HashMap<String, String>,
+}
+
+impl Attributes {
+    fn push(&mut self, attr: &Attribute) {
+        if let Some(new_value) = attr.value() {
+            if let Some(old_value) = self.attrs.get_mut(attr.name()) {
+                assert!(!old_value.is_empty());
+                old_value.push(',');
+                old_value.push_str(new_value);
+            } else {
+                self.attrs.insert(attr.name().into(), new_value.into());
+            }
+        } else {
+            assert!(!self.attrs.contains_key(attr.name()));
+            self.attrs.insert(attr.name().into(), "".into());
+        }
+    }
+
+    fn iter(&self) -> impl Iterator<Item = (&String, &String)> {
+        self.attrs.iter()
+    }
+}
+
 /// An attribute of an HTML element.
 #[derive(Clone, Debug)]
 pub struct Attribute {