feat: implement robust format identification, plugin availability checks, and automatic conversion path rerouting on failure

src/identifier.rs

@@ -15,14 +15,29 @@
 use crate::plugin::Plugin;
 use std::path::Path;
 
-pub fn identify_format(path: &str, plugins: &[Box<dyn Plugin>]) -> Option<&'static str> {
+pub fn identify_format(path: &str, input: &[u8], plugins: &[Box<dyn Plugin>]) -> Option<&'static str> {
+    let mut ext_str_opt = None;
+
+    if let Some(kind) = infer::get(input) {
+        ext_str_opt = Some(kind.extension());
+    }
+
     let p = Path::new(path);
-    let ext = p
+    let mut ext = p
         .extension()
         .and_then(|s| s.to_str())
-        .unwrap_or(path)
-        .to_lowercase();
-    let ext_str = match ext.as_str() {
+        .map(|s| s.to_lowercase());
+
+    if ext.is_none() {
+        ext = Some(path.to_lowercase());
+    }
+
+    let mut ext_str = ext.as_deref().unwrap_or("");
+    if ext_str_opt.is_some() {
+        ext_str = ext_str_opt.unwrap();
+    }
+
+    let ext_str = match ext_str {
         "jpg" => "jpeg",
         other => other,
     };
@@ -61,7 +76,7 @@ mod tests {
             fn $name() {
                 let mock = Box::new(MockPlugin);
                 let plugins: Vec<Box<dyn Plugin>> = vec![mock];
-                assert_eq!(identify_format($ext, &plugins), $expected);
+                assert_eq!(identify_format($ext, &[], &plugins), $expected);
             }
         };
     }