Handle whitespace in shebangs

CHANGELOG.md

@@ -6,6 +6,9 @@ Updated JavaScript, TypeScript, QML and Perl parsers.
 
 `Makefile*.in` is now detected as Makefile syntax.
 
+Improved shebang parsing with whitespace, e.g. `#! /bin/bash` is now
+detected as a shell script.
+
 Added support for Scheme and Smali.
 
 ### Diffing

src/parse/guess_language.rs

@@ -547,7 +547,7 @@ fn from_emacs_mode_header(src: &str) -> Option<Language> {
 /// Try to guess the language based on a shebang present in the source.
 fn from_shebang(src: &str) -> Option<Language> {
     lazy_static! {
-        static ref RE: Regex = Regex::new(r"#!(?:/usr/bin/env )?([^ ]+)").unwrap();
+        static ref RE: Regex = Regex::new(r"#! *(?:/usr/bin/env )?([^ ]+)").unwrap();
     }
     if let Some(first_line) = src.lines().next() {
         if let Some(cap) = RE.captures(first_line) {
@@ -635,6 +635,12 @@ mod tests {
         assert_eq!(guess(path, "#!/usr/bin/env python", &[]), Some(Python));
     }
 
+    #[test]
+    fn test_guess_by_shebang_with_space() {
+        let path = Path::new("foo");
+        assert_eq!(guess(path, "#! /bin/sh", &[]), Some(Bash));
+    }
+
     #[test]
     fn test_guess_by_emacs_mode() {
         let path = Path::new("foo");