cli: Don't highlight unknown languages

Previously, we'd show "Empty file".

radicle-cli/src/git/pretty_diff.rs

@@ -13,7 +13,7 @@ use crate::terminal::highlight::{Highlighter, Theme};
 use super::unified_diff::{Decode, HunkHeader};
 
 /// Blob returned by the [`Repo`] trait.
-#[derive(PartialEq, Eq)]
+#[derive(PartialEq, Eq, Debug)]
 pub enum Blob {
     Binary,
     Empty,
@@ -222,10 +222,10 @@ impl ToPretty for DiffContent {
         let mut blobs = Blobs::default();
 
         if let Some(Blob::Plain(content)) = old {
-            blobs.old = hi.highlight(context.path(), &content).ok().flatten();
+            blobs.old = hi.highlight(context.path(), &content).ok();
         }
         if let Some(Blob::Plain(content)) = new {
-            blobs.new = hi.highlight(context.path(), &content).ok().flatten();
+            blobs.new = hi.highlight(context.path(), &content).ok();
         }
         let mut vstack = term::VStack::default()
             .border(Some(term::colors::FAINT))

radicle-cli/src/terminal/highlight.rs

@@ -175,16 +175,15 @@ impl Builder {
 }
 
 impl Highlighter {
-    /// Highlight a source code file. Returns `None` if the file type was not recognized.
+    /// Highlight a source code file.
-    pub fn highlight(
+    pub fn highlight(&mut self, path: &Path, code: &[u8]) -> Result<Vec<term::Line>, ts::Error> {
-        &mut self,
-        path: &Path,
-        code: &[u8],
-    ) -> Result<Option<Vec<term::Line>>, ts::Error> {
         let theme = Theme::default();
         let mut highlighter = ts::Highlighter::new();
         let Some(config) = self.detect(path, code) else {
-            return Ok(None);
+            let Ok(code) = std::str::from_utf8(code) else {
+                return Err(ts::Error::Unknown);
+            };
+            return Ok(code.lines().map(term::Line::new).collect());
         };
         config.configure(HIGHLIGHTS);
 
@@ -193,7 +192,7 @@ impl Highlighter {
             None
         })?;
 
-        Builder::default().run(highlights, code, &theme).map(Some)
+        Builder::default().run(highlights, code, &theme)
     }
 
     /// Detect language.

radicle-cli/src/terminal/json.rs

@@ -6,10 +6,7 @@ use crate::terminal as term;
 pub fn to_pretty(value: &impl serde::Serialize, path: &Path) -> anyhow::Result<Vec<term::Line>> {
     let json = serde_json::to_string_pretty(&value)?;
     let mut highlighter = term::highlight::Highlighter::default();
+    let highlighted = highlighter.highlight(path, json.as_bytes())?;
 
-    if let Some(highlighted) = highlighter.highlight(path, json.as_bytes())? {
     Ok(highlighted)
-    } else {
-        Ok(json.split('\n').map(term::Line::new).collect())
-    }
 }