refactor: move embedded tests into dedicated test directory

tests/unit/syntax_languages.rs

@@ -0,0 +1,73 @@
+use super::*;
+
+#[test]
+fn selected_files_and_auxiliary_grammars_are_registered() {
+    for (filename, language) in [
+        ("main.rs", "Rust"),
+        ("Gemfile", "Ruby"),
+        ("main.py", "Python"),
+        ("package.json", "JSON"),
+        (".bashrc", "Bash"),
+        ("GNUmakefile", "Makefile"),
+        ("README.md", "Markdown"),
+        ("main.jsx", "JavaScript"),
+        ("main.ts", "TypeScript"),
+        ("index.html", "HTML"),
+        ("style.css", "CSS"),
+        ("config.yml", "YAML"),
+        ("Cargo.toml", "TOML"),
+        ("Cargo.lock", "TOML"),
+        ("main.c", "C"),
+        ("main.cpp", "C++"),
+        ("main.C", "C++"),
+        ("main.go", "Go"),
+        ("main.zig", "Zig"),
+    ] {
+        assert_eq!(
+            detect(Some(Path::new(filename)), None).map(|spec| spec.name),
+            Some(language)
+        );
+    }
+    let ts = detect(Some(Path::new("main.ts")), None).unwrap();
+    let tsx = detect(Some(Path::new("main.tsx")), None).unwrap();
+    assert_eq!(ts.name, tsx.name);
+    assert!(!std::ptr::eq(ts, tsx));
+    assert_ne!(ts.language, tsx.language);
+    assert!(std::ptr::eq(tsx, by_name("TSX").unwrap()));
+    assert!(by_name("markdown_inline").is_some());
+    for filename in [
+        "notes.txt",
+        "main.hs",
+        "main.scala",
+        "main.lua",
+        "Dockerfile",
+    ] {
+        assert!(detect(Some(Path::new(filename)), None).is_none());
+    }
+}
+
+#[test]
+fn shebangs_support_bom_env_options_and_filename_precedence() {
+    for (line, language) in [
+        ("#!/usr/bin/python3", "Python"),
+        ("\u{feff}#!/usr/bin/env -S python3.12 -u", "Python"),
+        ("#!/usr/bin/env -u PYTHONHOME FOO=bar python3", "Python"),
+        ("#!/usr/bin/ruby3.3", "Ruby"),
+        ("#!/bin/bash", "Bash"),
+        ("#! /usr/bin/env node", "JavaScript"),
+    ] {
+        assert_eq!(
+            detect(None, Some(line)).map(|spec| spec.name),
+            Some(language)
+        );
+    }
+    assert_eq!(
+        detect(Some(Path::new("main.rs")), Some("#!/bin/bash"))
+            .unwrap()
+            .name,
+        "Rust"
+    );
+    assert!(detect(None, Some("#!/usr/bin/python-not-real")).is_none());
+    assert!(detect(None, Some("#!/usr/bin/perl")).is_none());
+    assert!(detect(None, Some("plain text")).is_none());
+}