gh-407: Mark optional platform tags in online aliases

src/manage/installs.py

@@ -174,7 +174,7 @@ def _make_alias_name_sortkey(n):
     return re.sub(r"(\d+|\[|\])", _sk_sub, n)
 
 
-def get_install_alias_names(aliases, friendly=True, windowed=True):
+def get_install_alias_names(aliases, friendly=True, windowed=True, default_platform=None):
     if not windowed:
         aliases = [a for a in aliases if not a.get("windowed")]
     if not friendly:
@@ -191,11 +191,17 @@ def get_install_alias_names(aliases, friendly=True, windowed=True):
 
     result = []
     for k, (n1, n2, n3) in seen.items():
+        plat_parts = plats.get(k)
+        plat = _make_opt_part(plat_parts)
+        if default_platform and plat_parts == {default_platform}:
+            # The bare alias was already shown for another install, but the
+            # suffix is still optional when it matches the default platform.
+            plat = f"[{default_platform}]"
         result.append("".join([
             n1,
             _make_opt_part(has_w.get(k)),
             n2,
-            _make_opt_part(plats.get(k)),
+            plat,
             n3,
         ]))
     return sorted(result, key=_make_alias_name_sortkey)

src/manage/list_command.py

@@ -6,13 +6,16 @@
 LOGGER = logging.LOGGER
 
 
-def _format_alias(i, seen):
+def _format_alias(cmd, i, seen):
     from manage.installs import get_install_alias_names
     aliases = [a for a in i.get("alias", ()) if a["name"].casefold() not in seen]
     seen.update(a["name"].casefold() for a in aliases)
 
     include_w = LOGGER.would_log_to_console(logging.VERBOSE)
-    names = get_install_alias_names(aliases, windowed=include_w)
+    default_platform = cmd.default_platform if cmd else None
+    names = get_install_alias_names(
+        aliases, windowed=include_w, default_platform=default_platform
+    )
     return ", ".join(names)
 
 
@@ -46,7 +49,7 @@ def format_table(cmd, installs):
     seen_alias = set()
     installs = [{
         **i,
-        "alias": _format_alias(i, seen_alias),
+        "alias": _format_alias(cmd, i, seen_alias),
         "sort-version": str(i['sort-version']),
         "default-star": "",
         "tag-with-co": _format_tag_with_co(cmd, i),

tests/test_list.py

@@ -139,6 +139,50 @@ def test_format_table_aliases(assert_log):
     )
 
 
+def test_format_table_aliases_default_platform(assert_log):
+    # https://github.com/python/pymanager/issues/407
+    # Aliases from the online index, in feed order. Each install lists both
+    # the bare alias and its platform-specific variant; format_table shows
+    # only the first occurrence of each name, so the -64 install is left
+    # with lone "-64" names. Those must still render as optional ("[-64]"),
+    # mirroring how the Tag column marks the default platform.
+    import types
+
+    def online_aliases(plat):
+        return [
+            {"name": "python3.15.exe", "target": "python.exe"},
+            {"name": f"python3.15{plat}.exe", "target": "python.exe"},
+            {"name": "python3.exe", "target": "python.exe"},
+            {"name": f"python3{plat}.exe", "target": "python.exe"},
+            {"name": "pythonw3.15.exe", "target": "pythonw.exe", "windowed": 1},
+            {"name": f"pythonw3.15{plat}.exe", "target": "pythonw.exe", "windowed": 1},
+            {"name": "pythonw3.exe", "target": "pythonw.exe", "windowed": 1},
+            {"name": f"pythonw3{plat}.exe", "target": "pythonw.exe", "windowed": 1},
+        ]
+
+    def online_install(tag, plat):
+        return {
+            "company": "PythonCore",
+            "tag": tag,
+            "display-name": "Python 3.15.0rc2",
+            "sort-version": "3.15.0rc2",
+            "alias": online_aliases(plat),
+        }
+
+    cmd = types.SimpleNamespace(default_platform="-64")
+    list_command.format_table(cmd, [
+        online_install("3.15-dev-32", "-32"),
+        online_install("3.15-dev-64", "-64"),
+        online_install("3.15-dev-arm64", "-arm64"),
+    ])
+    assert_log(
+        (r"!B!Tag\s+Name\s+Managed By\s+Version\s+Alias\s*!W!", ()),
+        (r"3\.15-dev-32.*" + re.escape("python[w]3[-32].exe, python[w]3.15[-32].exe"), ()),
+        (r"3\.15-dev\[-64\].*" + re.escape("python[w]3[-64].exe, python[w]3.15[-64].exe"), ()),
+        (r"3\.15-dev-arm64.*" + re.escape("python[w]3-arm64.exe, python[w]3.15-arm64.exe"), ()),
+    )
+
+
 def test_format_table_truncated(assert_log):
     list_command.format_table(None, [
         {