Add Julia language recognition support. Fixes #4596

Signed-off-by: HasTheDev <hassanazam2021@gmail.com>

Author: HasTheDev

src/typecode/contenttype.py

@@ -742,7 +742,8 @@ def is_source(self):
         elif self.is_makefile or self.is_js_map:
             return False
 
-        elif self.is_java_source is True or self.is_c_source is True:
+        # Recognize "known-by-extension" source types
+        elif self.is_java_source or self.is_c_source or self.is_julia_source:
             return True
 
         elif self.filetype_pygment or self.is_script is True:
@@ -758,9 +759,19 @@ def programming_language(self):
         string.
         """
         if self.is_source:
+            # If the custom extension check found Julia, use that name explicitly
+            if self.is_julia_source:
+                return "Julia"
             return self.filetype_pygment or ""
         return ""
 
+    @property
+    def is_julia_source(self):
+        """
+        Return True if the file is Julia source code based on .jl extension.
+        """
+        return self.is_file and self.location.lower().endswith(".jl")
+
     @property
     def is_c_source(self):
         C_EXTENSIONS = set(
@@ -950,7 +961,8 @@ def get_text_file_start(location, length=4096):
         with open(location, "rb") as f:
             content = text.as_unicode(f.read(length))
     finally:
-        return content
+        pass
+    return content
 
 
 def get_filetype(location):

tests/test_contenttype.py

@@ -230,6 +230,17 @@ def test_compiled_elf_so_2(self):
         assert get_filetype(test_file) in expected
         assert get_filetype_pygment(test_file) == ""
 
+    def test_programming_language_detection_for_julia(self):
+        # Create a temporary julia file
+        test_file = self.get_temp_file("test.jl")
+        with open(test_file, "w") as f:
+            f.write('println("Hello Julia")')
+
+        # Get the type and check identification
+        T = get_type(test_file)
+        assert is_source(test_file)
+        assert T.programming_language == "Julia"
+
     @pytest.mark.xfail(
         on_mac or on_windows,
         reason="Somehow we get really weird results on macOS with libmagic 5.38 and mac, win32 on libmagic 5.39: "