Fix bug when calling generate

Author: Hugo Osvaldo Barrera

barcode/__init__.py

@@ -3,6 +3,11 @@
 created as SVG objects. If Pillow is installed, the barcodes can also be
 rendered as images (all formats supported by Pillow).
 """
+import os
+from typing import BinaryIO
+from typing import Dict
+from typing import Union
+
 from barcode.codex import Code128
 from barcode.codex import Code39
 from barcode.codex import Gs1_128
@@ -76,15 +81,37 @@ def get_class(name):
 
 
 def generate(
-    name, code, writer=None, output=None, writer_options=None, text=None,
+    name: str,
+    code: str,
+    writer=None,
+    output: Union[str, os.PathLike, BinaryIO] = None,
+    writer_options: Dict = None,
+    text: str = None,
 ):
-    writer_options = writer_options or {}
-    barcode = get(name, code, writer, writer_options=writer_options)
+    """Shortcut to generate a barcode in one line.
+
+    :param name: Name of the type of barcode to use.
+    :param code: Data to encode into the barcode.
+    :param writer: A writer to use (e.g.: ImageWriter or SVGWriter).
+    :param output: Destination file-like or path-like where to save the generated
+     barcode.
+    :param writer_options: Options to pass on to the writer instance.
+    :param text: Text to render under the barcode.
+    """
+    from barcode.base import Barcode
+
+    writer = writer or Barcode.default_writer()
+    writer.set_options(writer_options or {})
+
+    barcode = get(name, code, writer)
+
     if isinstance(output, str):
         fullname = barcode.save(output, writer_options, text)
         return fullname
-    else:
+    elif output:
         barcode.write(output, writer_options, text)
+    else:
+        raise TypeError("'output' cannot be None")
 
 
 get_barcode = get

tests/test_init.py

@@ -0,0 +1,39 @@
+import os
+from io import BytesIO
+
+import pytest
+
+import barcode
+from barcode.writer import SVGWriter
+
+PATH = os.path.dirname(os.path.abspath(__file__))
+TESTPATH = os.path.join(PATH, "test_outputs")
+
+
+def test_generate_without_output():
+    with pytest.raises(TypeError, match="'output' cannot be None"):
+        barcode.generate("ean13", "123455559121112")
+
+
+def test_generate_with_file():
+    with open(f"{TESTPATH}/generate_with_file.jpeg", "wb") as f:
+        barcode.generate("ean13", "123455559121112", output=f)
+
+
+def test_generate_with_filepath():
+    # FIXME: extension is added to the filepath even if you include it.
+    rv = barcode.generate(
+        "ean13", "123455559121112", output=f"{TESTPATH}/generate_with_filepath"
+    )
+    assert rv == os.path.abspath(f"{TESTPATH}/generate_with_filepath.svg")
+
+
+def test_generate_with_file_and_writer():
+    with open(f"{TESTPATH}/generate_with_file_and_writer.jpeg", "wb") as f:
+        barcode.generate("ean13", "123455559121112", output=f, writer=SVGWriter())
+
+
+def test_generate_with_bytesio():
+    bio = BytesIO()
+    barcode.generate("ean13", "123455559121112", output=bio)
+    assert len(bio.getvalue()) == 6127