Allow for files to be specified in the corpus file

crates/format/src/corpus.rs

@@ -35,6 +35,7 @@ impl Corpus {
 ///
 /// `path` is expected to be a directory.
 pub fn collect_metadata(path: &Path, tests: &mut Vec<MetadataFile>) {
+    if path.is_dir() {
         let dir_entry = match std::fs::read_dir(path) {
             Ok(dir_entry) => dir_entry,
             Err(error) => {
@@ -64,4 +65,17 @@ pub fn collect_metadata(path: &Path, tests: &mut Vec<MetadataFile>) {
                 }
             }
         }
+    } else {
+        let Some(extension) = path.extension() else {
+            tracing::error!("Failed to get file extension");
+            return;
+        };
+        if extension.eq_ignore_ascii_case("sol") || extension.eq_ignore_ascii_case("json") {
+            if let Some(metadata) = MetadataFile::try_from_file(path) {
+                tests.push(metadata)
+            }
+        } else {
+            tracing::error!(?extension, "Unsupported file extension");
+        }
+    }
 }