chore: add better error message if unknown language is found

src/execute.rs

@@ -36,7 +36,7 @@ impl CodeExecutor {
                     return Err(LoadExecutorsError::InvalidExecutor(path, "non .sh extension"));
                 }
                 let language: CodeLanguage = match name.parse() {
-                    Ok(CodeLanguage::Unknown) => {
+                    Ok(CodeLanguage::Unknown(_)) => {
                         return Err(LoadExecutorsError::InvalidExecutor(path, "unknown language"));
                     }
                     Ok(language) => language,
@@ -295,11 +295,6 @@ echo 'hello world'
         assert_eq!(state.output, expected_lines);
     }
 
-    #[test]
-    fn validate_builtin_executors() {
-        assert!(EXECUTORS.get(&CodeLanguage::Unknown).is_none(), "unknown language in executors");
-    }
-
     #[test]
     fn custom_executor() {
         let dir = tempdir().unwrap();

src/markdown/code.rs

@@ -180,7 +180,7 @@ mod test {
 
     #[test]
     fn unknown_language() {
-        assert_eq!(parse_language("potato"), CodeLanguage::Unknown);
+        assert_eq!(parse_language("potato"), CodeLanguage::Unknown("potato".to_string()));
     }
 
     #[test]

src/markdown/elements.rs

@@ -237,7 +237,7 @@ pub enum CodeLanguage {
     Terraform,
     TypeScript,
     Typst,
-    Unknown,
+    Unknown(String),
     Xml,
     Yaml,
     Vue,
@@ -308,7 +308,7 @@ impl FromStr for CodeLanguage {
             "yaml" => Yaml,
             "vue" => Vue,
             "zig" => Zig,
-            _ => Unknown,
+            other => Unknown(other.to_string()),
         };
         Ok(language)
     }

src/processing/builder.rs

@@ -706,7 +706,7 @@ impl<'a> PresentationBuilder<'a> {
     fn highlight_lines(&self, code: &Code) -> (Vec<HighlightedLine>, Rc<RefCell<HighlightContext>>) {
         let lines = CodePreparer::new(&self.theme).prepare(code);
         let block_length = lines.iter().map(|line| line.width()).max().unwrap_or(0);
-        let mut empty_highlighter = self.highlighter.language_highlighter(&CodeLanguage::Unknown);
+        let mut empty_highlighter = self.highlighter.language_highlighter(&CodeLanguage::Unknown(String::new()));
         let mut code_highlighter = self.highlighter.language_highlighter(&code.language);
         let padding_style = {
             let mut highlighter = self.highlighter.language_highlighter(&CodeLanguage::Rust);

src/processing/code.rs

@@ -189,7 +189,7 @@ mod test {
         let input_lines = "hi\n".repeat(total_lines);
         let code = Code {
             contents: input_lines,
-            language: CodeLanguage::Unknown,
+            language: CodeLanguage::Unknown("".to_string()),
             attributes: CodeAttributes { line_numbers: true, ..Default::default() },
         };
         let lines = CodePreparer { theme: &Default::default() }.prepare(&code);

src/render/highlighting.rs

@@ -157,7 +157,7 @@ impl CodeHighlighter {
             TypeScript => "ts",
             Typst => "txt",
             // default to plain text so we get the same look&feel
-            Unknown => "txt",
+            Unknown(_) => "txt",
             Vue => "vue",
             Xml => "xml",
             Yaml => "yaml",