Make it possible to undefine macros and add a macros example to the R…

…EADME (#244)

Make it possible to undefine macros and add a macros example to the README

Fixes #243.

Reviewed-by: František Lachman

README.md

@@ -78,6 +78,16 @@ with Specfile('test.spec') as specfile:
     ...
 ```
 
+### Defining and undefining macros
+
+```python
+# override macros loaded from system macro files
+specfile = Specfile('test.spec', macros=[('fedora', '38'), ('dist', '.fc38')])
+
+# undefine a system macro (in case it's defined)
+specfile = Specfile('test.spec', macros=[('rhel', None)])
+```
+
 ### Low-level manipulation
 
 ```python

specfile/macros.py

@@ -169,7 +169,7 @@ def remove(cls, macro: str) -> None:
         while retry < MAX_REMOVAL_RETRIES:
             rpm.delMacro(macro)
             try:
-                if cls.expand(f"%{macro}") == f"%{macro}":
+                if cls.expand(f"%{{{macro}}}") == f"%{{{macro.replace('%%', '%')}}}":
                     break
             except RPMException:
                 # the macro can't be expanded, but it still exists

specfile/spec_parser.py

@@ -49,7 +49,7 @@ class SpecParser:
     def __init__(
         self,
         sourcedir: Path,
-        macros: Optional[List[Tuple[str, str]]] = None,
+        macros: Optional[List[Tuple[str, Optional[str]]]] = None,
         force_parse: bool = False,
     ) -> None:
         self.sourcedir = sourcedir
@@ -170,7 +170,9 @@ def restore(key):
                 restore(key)
 
     def _do_parse(
-        self, content: str, extra_macros: Optional[List[Tuple[str, str]]] = None
+        self,
+        content: str,
+        extra_macros: Optional[List[Tuple[str, Optional[str]]]] = None,
     ) -> Tuple[rpm.spec, bool]:
         """
         Parses the content of a spec file.
@@ -190,7 +192,10 @@ def _do_parse(
         def get_rpm_spec(content, flags):
             Macros.reinit()
             for name, value in self.macros + (extra_macros or []):
-                Macros.define(name, value)
+                if value is None:
+                    Macros.remove(name)
+                else:
+                    Macros.define(name, value)
             Macros.define("_sourcedir", str(self.sourcedir))
             with tempfile.NamedTemporaryFile() as tmp:
                 tmp.write(content.encode())
@@ -318,7 +323,9 @@ def collect_loaded_sources(content):
             return get_rpm_spec(content, rpm.RPMSPEC_ANYARCH), tainted
 
     def parse(
-        self, content: str, extra_macros: Optional[List[Tuple[str, str]]] = None
+        self,
+        content: str,
+        extra_macros: Optional[List[Tuple[str, Optional[str]]]] = None,
     ) -> None:
         """
         Parses the content of a spec file and updates the `spec` and `tainted` attributes.

specfile/specfile.py

@@ -43,7 +43,7 @@ def __init__(
         path: Union[Path, str],
         sourcedir: Optional[Union[Path, str]] = None,
         autosave: bool = False,
-        macros: Optional[List[Tuple[str, str]]] = None,
+        macros: Optional[List[Tuple[str, Optional[str]]]] = None,
         force_parse: bool = False,
     ) -> None:
         """
@@ -124,7 +124,7 @@ def sourcedir(self, value: Union[Path, str]) -> None:
         self._parser.sourcedir = Path(value)
 
     @property
-    def macros(self) -> List[Tuple[str, str]]:
+    def macros(self) -> List[Tuple[str, Optional[str]]]:
         """List of extra macro definitions."""
         return self._parser.macros
 
@@ -167,7 +167,7 @@ def save(self) -> None:
     def expand(
         self,
         expression: str,
-        extra_macros: Optional[List[Tuple[str, str]]] = None,
+        extra_macros: Optional[List[Tuple[str, Optional[str]]]] = None,
         skip_parsing: bool = False,
     ) -> str:
         """

tests/unit/test_macros.py

@@ -81,14 +81,19 @@ def test_macros_remove():
     Macros.remove("test")
     Macros.remove("non_existent_macro")
     assert Macros.dump() == macros
+    rpm.addMacro("%test", "1")
+    rpm.addMacro("te%st%%", "2")
+    Macros.remove("%test")
+    Macros.remove("te%st%%")
+    assert Macros.dump() == macros
 
 
 def test_macros_remove_failure():
     # Expansion and removal of built-in macros is broken before rpm 4.17,
     # ensure that we are not stuck in an infinite loop
     rpm.reloadConfig()
     rpm.addMacro("foo", "bar")
-    flexmock(rpm).should_receive("expandMacro").with_args("%foo").and_raise(rpm.error)
+    flexmock(rpm).should_receive("expandMacro").with_args("%{foo}").and_raise(rpm.error)
     with pytest.raises(MacroRemovalException):
         Macros.remove("foo")
 

tests/unit/test_spec_parser.py

@@ -5,6 +5,7 @@
 from pathlib import Path
 
 import rpm
+from flexmock import flexmock
 
 from specfile.spec_parser import SpecParser
 
@@ -39,3 +40,27 @@ def test_copy_spec_parser():
     deep_copy = copy.deepcopy(parser)
     assert deep_copy == parser
     assert deep_copy is not parser
+
+
+def test_spec_parser_macros():
+    flexmock(rpm).should_call("delMacro").with_args(
+        "fedora"
+    ).at_least().once().ordered()
+    flexmock(rpm).should_call("delMacro").with_args("rhel").at_least().once().ordered()
+    flexmock(rpm).should_call("addMacro").with_args("rhel", "9").once().ordered()
+    # we don't care about the rest
+    flexmock(rpm).should_call("addMacro")
+    flexmock(rpm).should_call("delMacro")
+    parser = SpecParser(Path("."), macros=[("fedora", None), ("rhel", "9")])
+    spec, _ = parser._do_parse(
+        (
+            "Name:           test\n"
+            "Version:        0.1\n"
+            "Release:        1%{?dist}\n"
+            "Summary:        Test package\n"
+            "License:        MIT\n"
+            "\n"
+            "%description\n"
+            "Test package\n"
+        ),
+    )