Fix tokenization of attributes without value (#144)

Resolves: #142 

Backports:
- Release 2.2.2
- Release 2.1.2
- Release 2.0.3 (?)

src/pygerber/gerberx3/tokenizer/grammar.py

@@ -1,4 +1,5 @@
 """GerberX3 grammar."""
+
 from __future__ import annotations
 
 from dataclasses import dataclass
@@ -887,29 +888,30 @@ def _build_attribute_tokens(self, *, statement: bool = False) -> ParserElement:
         aperture_attribute_name = self._build_name().set_name("aperture attribute name")
         object_attribute_name = self._build_name().set_name("object attribute name")
 
+        comma = Literal(",")
+        comma_with_field = comma + self._build_field()
+        maybe_comma_or_maybe_comma_with_field = Opt(comma_with_field | comma)
+
         # Set a file attribute.
         tf = wrapper(
             self.options.tf_file_attribute_token_cls,
             Literal("TF")
             + file_attribute_name.set_results_name("attribute_name")
-            + Literal(",")
-            + Opt(self._build_field()),
+            + maybe_comma_or_maybe_comma_with_field,
         )
         # Add an aperture attribute to the dictionary or modify it.
         ta = wrapper(
             self.options.ta_aperture_attribute_token_cls,
             Literal("TA")
             + aperture_attribute_name.set_results_name("attribute_name")
-            + Literal(",")
-            + Opt(self._build_field()),
+            + maybe_comma_or_maybe_comma_with_field,
         )
         # Add an object attribute to the dictionary or modify it.
         to = wrapper(
             self.options.to_object_attribute_token_cls,
             Literal("TO")
             + object_attribute_name.set_results_name("attribute_name")
-            + Literal(",")
-            + Opt(self._build_field()),
+            + maybe_comma_or_maybe_comma_with_field,
         )
         # Delete one or all attributes in the dictionary.
         td = wrapper(

src/pygerber/gerberx3/tokenizer/tokens/ta_aperture_attribute.py

@@ -1,6 +1,5 @@
 """Comment token."""
 
-
 from __future__ import annotations
 
 from typing import TYPE_CHECKING
@@ -39,7 +38,8 @@ def get_gerber_code(
         endline: str = "\n",  # noqa: ARG002
     ) -> str:
         """Get gerber code represented by this token."""
-        return f"TA{self.name},{self.value}"
+        value = f",{self.value}" if self.value else ""
+        return f"TA{self.name}{value}"
 
     def __str__(self) -> str:
         return f"{super().__str__()}::[{self.name} -> {self.value}]"

src/pygerber/gerberx3/tokenizer/tokens/td_delete_attribute.py

@@ -1,6 +1,5 @@
 """Comment token."""
 
-
 from __future__ import annotations
 
 from typing import TYPE_CHECKING, Optional
@@ -55,7 +54,8 @@ def get_gerber_code(
         endline: str = "\n",  # noqa: ARG002
     ) -> str:
         """Get gerber code represented by this token."""
-        return f"TD{self.name if self.name is not None else ''}"
+        name = self.name if self.name is not None else ""
+        return f"TD{name}"
 
     def __str__(self) -> str:
         return f"{super().__str__()}::[{self.name}]"

src/pygerber/gerberx3/tokenizer/tokens/tf_file_attribute.py

@@ -1,6 +1,5 @@
 """Comment token."""
 
-
 from __future__ import annotations
 
 from typing import TYPE_CHECKING
@@ -35,7 +34,8 @@ def get_gerber_code(
         endline: str = "\n",  # noqa: ARG002
     ) -> str:
         """Get gerber code represented by this token."""
-        return f"TF{self.name},{self.value}"
+        value = f",{self.value}" if self.value else ""
+        return f"TF{self.name}{value}"
 
     def __str__(self) -> str:
         return f"{super().__str__()}::[{self.name} -> {self.value}]"

src/pygerber/gerberx3/tokenizer/tokens/to_object_attribute.py

@@ -37,7 +37,8 @@ def get_gerber_code(
         endline: str = "\n",  # noqa: ARG002
     ) -> str:
         """Get gerber code represented by this token."""
-        return f"TO{self.name},{self.value}"
+        value = f",{self.value}" if self.value else ""
+        return f"TO{self.name}{value}"
 
     def __str__(self) -> str:
         return f"{super().__str__()}::[{self.name} -> {self.value}]"

test/examples/test_examples.py

@@ -14,6 +14,10 @@
     renderer_2_svg_render,
 )
 
+import pytest
+
+from pygerber.gerberx3.renderer2.svg import IS_SVG_BACKEND_AVAILABLE
+
 DIRECTORY = Path(__file__).parent
 
 
@@ -61,5 +65,6 @@ def test_renderer_2_raster_render() -> None:
     renderer_2_raster_render.render()
 
 
+@pytest.mark.skipif(not IS_SVG_BACKEND_AVAILABLE, reason="SVG backend required")
 def test_renderer_2_svg_render() -> None:
     renderer_2_svg_render.render()

test/gerberx3/test_renderer2/common.py

@@ -12,7 +12,11 @@
 from pygerber.gerberx3.parser2.parser2 import Parser2
 from pygerber.gerberx3.renderer2.abstract import ImageRef
 from pygerber.gerberx3.renderer2.raster import RasterRenderer2, RasterRenderer2Hooks
-from pygerber.gerberx3.renderer2.svg import SvgRenderer2, SvgRenderer2Hooks
+from pygerber.gerberx3.renderer2.svg import (
+    IS_SVG_BACKEND_AVAILABLE,
+    SvgRenderer2,
+    SvgRenderer2Hooks,
+)
 from pygerber.gerberx3.tokenizer.tokenizer import Tokenizer
 
 if TYPE_CHECKING:
@@ -72,6 +76,10 @@ def make_svg_renderer2_test(
     """
     debug_output_directory = Path(test_file_path).parent / ".output" / "svg"
 
+    @pytest.mark.skipif(
+        IS_SVG_BACKEND_AVAILABLE is False,
+        reason="No SVG backend available",
+    )
     @pytest.mark.parametrize(
         ("directory", "file_name"),
         sorted(find_gerberx3_asset_files(path_to_assets)),