fix: never extend a RetroPie list of examples

scripts/exporter/retropie_exporter.py

@@ -49,6 +49,7 @@ _FILENAME = re.compile(r"[A-Za-z0-9][\w.+-]*\.[A-Za-z0-9]{1,5}\b")
 _BIOS_CLAUSE = re.compile(r"BIOS\b.*?(?=\\n|$)", re.DOTALL)
 _BIOS_NOUN = re.compile(r"BIOS (files?)\b")
 _SEPARATOR = re.compile(r"\s*(?:,\s*(?:and\s+)?|and\s+)")
+_EXAMPLES = re.compile(r"\b(?:e\.?g\b|for example|for instance|such as|like)\W*$", re.I)
 
 
 class Exporter(BaseExporter):
@@ -148,7 +149,8 @@ class Exporter(BaseExporter):
         A list of alternatives ("a or b", "a/b") is not an enumeration: an
         appended ", c" reads as one more required file and the plural turns
         "one of these" into "all of these". Such a list is left alone, and so
-        is one with words between its names, which a rewrite would lose.
+        are a list of examples ("eg. a, b") and one with words between its
+        names, which a rewrite would lose.
         """
         clause = _BIOS_CLAUSE.search(help_text)
         if clause is None:
@@ -160,6 +162,10 @@ class Exporter(BaseExporter):
         between = text[names[0].start():names[-1].end()]
         if re.search(r"\bor\b|/", between):
             return None
+        # "a minimum of two BIOS files (eg. a, b)" names examples, not the
+        # set: an appended name reads as one more required file.
+        if _EXAMPLES.search(text[:names[0].start()]):
+            return None
         gaps = [text[a.end():b.start()] for a, b in zip(names, names[1:])]
         if not all(_SEPARATOR.fullmatch(gap) for gap in gaps):
             return None

tests/test_export_counts.py

@@ -543,6 +543,19 @@ class RetroPieProposals(unittest.TestCase):
                     RetroPie._extended(help_text, enumeration, missing), expected
                 )
 
+    def test_a_list_of_examples_is_not_extended(self):
+        # lr-neocd: "a minimum of two BIOS files (eg. ng-lo.rom,
+        # uni-bioscd.rom)" became "(eg. ng-lo.rom, uni-bioscd.rom and
+        # neocd.bin)": two announced, three named, read as all required.
+        help_text = (
+            "You will need a minimum of two BIOS files (eg. ng-lo.rom, "
+            "uni-bioscd.rom) which should be copied to $biosdir/neocd"
+        )
+        self.assertIsNone(RetroPie._enumeration(help_text))
+        self.assertIsNone(RetroPie._enumeration(
+            "Copy BIOS files such as a.bin and b.bin to $biosdir"
+        ))
+
     def test_words_between_names_are_not_rewritten(self):
         self.assertIsNone(
             RetroPie._enumeration("BIOS files a.bin (US) and b.bin to $biosdir")