add id to Listing with number attribute for cross reference

update tests after new attribute id added

Co-authored-by: Chris Krycho <[email protected]>

Author: 2 people

packages/mdbook-trpl/src/listing/mod.rs

@@ -221,7 +221,13 @@ struct Listing {
 
 impl Listing {
     fn opening_html(&self) -> String {
-        let figure = String::from("<figure class=\"listing\">\n");
+        let id_attribute = self
+            .number
+            .as_ref()
+            .map(|number| format!(" id=\"listing-{number}\""))
+            .unwrap_or_default();
+
+        let figure = format!("<figure class=\"listing\"{id_attribute}>\n");
 
         match self.file_name.as_ref() {
             Some(file_name) => format!(

packages/mdbook-trpl/src/listing/tests.rs

@@ -18,7 +18,7 @@ fn main() {}
 
     assert_eq!(
         &result.unwrap(),
-        r#"<figure class="listing">
+        r#"<figure class="listing" id="listing-1-2">
 <span class="file-name">Filename: src/main.rs</span>
 
 ````rust
@@ -80,7 +80,7 @@ fn get_a_box_of<T>(t: T) -> Box<T> {
 
     assert_eq!(
         &result.unwrap(),
-        r#"<figure class="listing">
+        r#"<figure class="listing" id="listing-34-5">
 
 ````rust
 fn get_a_box_of<T>(t: T) -> Box<T> {
@@ -117,7 +117,7 @@ Save the file and go back to your terminal window"#,
         result.unwrap(),
         r#"Now open the *main.rs* file you just created and enter the code in Listing 1-1.
 
-<figure class="listing">
+<figure class="listing" id="listing-1-1">
 <span class="file-name">Filename: main.rs</span>
 
 ````rust
@@ -155,7 +155,7 @@ This is the closing."#,
         result.unwrap(),
         r#"This is the opening.
 
-<figure class="listing">
+<figure class="listing" id="listing-1-1">
 
 ````rust
 fn main() {}