Refactor language detection in a util module

2 files changed, 34 insertions, 0 deletions

diff --git a/src/util/language.rs b/src/util/language.rs
new file mode 100644
index 0000000..fae7bf9
--- /dev/null
+++ b/src/util/language.rs
@@ -0,0 +1,33 @@
+use std::path::Path;
+
+pub fn detect_language(filename: &Path, contents: &str) -> &'static str {
+    detect_from_extension(filename)
+        .or_else(|| detect_from_shebang(contents))
+        .unwrap_or("")
+}
+
+fn detect_from_extension(filename: &Path) -> Option<&'static str> {
+    let ext = filename
+        .extension()
+        .and_then(|e| e.to_str())
+        .map(|e| e.to_ascii_lowercase());
+    let ext_str = ext.as_deref();
+    match ext_str {
+        Some("rs") => Some("rust"),
+        Some("py") => Some("python"),
+        Some("json") => Some("json"),
+        _ => None,
+    }
+}
+
+fn detect_from_shebang(contents: &str) -> Option<&'static str> {
+    if let Some(first_line) = contents.lines().next() {
+        if first_line.contains("python") {
+            return Some("python");
+        }
+        if first_line.contains("bash") {
+            return Some("bash");
+        }
+    }
+    None
+}
diff --git a/src/util/mod.rs b/src/util/mod.rs
index 1ba817e..5595a45 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1 +1,2 @@
+pub mod language;
 pub mod path_display;