From 91db24fc9a9ba09f27d59a1fa07ac7719a6f8a81 Mon Sep 17 00:00:00 2001
From: Wilfred Hughes <me@wilfred.me.uk>
Date: Mon, 27 Dec 2021 12:38:22 -0800
Subject: [PATCH] Add language detection based on whole file names

---
 CHANGELOG.md          |  4 ++++
 src/guess_language.rs | 29 ++++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a7e89521e..767cebf70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## 0.14 (unreleased)
 
+### Parsing
+
+Improved language detection for whole file names without an extension.
+
 ### Display
 
 Display width can now be overridden by setting the environment
diff --git a/src/guess_language.rs b/src/guess_language.rs
index 7a54a694a..b3fefc243 100644
--- a/src/guess_language.rs
+++ b/src/guess_language.rs
@@ -33,12 +33,29 @@ pub enum Language {
 use Language::*;
 
 pub fn guess(path: &Path) -> Option<Language> {
+    if let Some(lang) = from_name(path) {
+        return Some(lang);
+    }
+
     match path.extension() {
         Some(extension) => from_extension(extension),
         None => None,
     }
 }
 
+fn from_name(path: &Path) -> Option<Language> {
+    match path.file_name() {
+        Some(name) => match name.to_string_lossy().borrow() {
+            ".bashrc" | ".bash_profile" | ".profile" => Some(Bash),
+            ".emacs" | "_emacs" | "Cask" => Some(EmacsLisp),
+            "TARGETS" | "BUCK" | "DEPS" => Some(Python),
+            "Gemfile" | "Rakefile" => Some(Ruby),
+            _ => None,
+        },
+        None => None,
+    }
+}
+
 fn from_extension(extension: &OsStr) -> Option<Language> {
     // TODO: find a nice way to extract name and extension information
     // from the package.json in these parsers.
@@ -61,7 +78,7 @@ fn from_extension(extension: &OsStr) -> Option<Language> {
         }
         "cs" => Some(CSharp),
         "css" => Some(Css),
-        "el" | ".emacs" => Some(EmacsLisp),
+        "el" => Some(EmacsLisp),
         "ex" | "exs" => Some(Elixir),
         "go" => Some(Go),
         "hs" => Some(Haskell),
@@ -72,8 +89,8 @@ fn from_extension(extension: &OsStr) -> Option<Language> {
         "lisp" | "lsp" | "asd" => Some(CommonLisp),
         "ml" => Some(OCaml),
         "mli" => Some(OCamlInterface),
-        "py" | "py3" | "pyi" | "TARGETS" | "BUCK" | "bzl" => Some(Python),
-        "rb" | "spec" | "rake" => Some(Ruby),
+        "py" | "py3" | "pyi" | "bzl" => Some(Python),
+        "rb" | "builder" | "spec" | "rake" => Some(Ruby),
         "rs" => Some(Rust),
         "ts" => Some(TypeScript),
         "tsx" => Some(Tsx),
@@ -91,4 +108,10 @@ mod tests {
         let path = Path::new("foo.el");
         assert_eq!(guess(path), Some(EmacsLisp));
     }
+
+    #[test]
+    fn test_guess_by_whole_name() {
+        let path = Path::new("foo/.bashrc");
+        assert_eq!(guess(path), Some(Bash));
+    }
 }