Remove --enable-extension

Redundant if the default behaviour is to only run them if they exist.

Author: honno

README.md

@@ -136,8 +136,7 @@ issues](https://github.com/data-apis/array-api-tests/issues/) to us.
 By default, tests for the optional Array API extensions such as
 [`linalg`](https://data-apis.org/array-api/latest/extensions/linear_algebra_functions.html)
 will be skipped if not present in the specified array module. You can purposely
-skip testing extension(s) via the `--disable-extension` option, and likewise
-purposely test them via the `--enable-extension` option.
+skip testing extension(s) via the `--disable-extension` option.
 
 The tests make heavy use
 [Hypothesis](https://hypothesis.readthedocs.io/en/latest/). You can configure

conftest.py

@@ -27,14 +27,7 @@ def pytest_addoption(parser):
         action="store_true",
         help="disable the Hypothesis deadline",
     )
-    # enable/disable extensions
-    parser.addoption(
-        "--enable-extension",
-        metavar="ext",
-        nargs="+",
-        default=[],
-        help="enable testing for Array API extension(s)",
-    )
+    # disable extensions
     parser.addoption(
         "--disable-extension",
         metavar="ext",
@@ -82,21 +75,17 @@ def xp_has_ext(ext: str) -> bool:
 
 
 def pytest_collection_modifyitems(config, items):
-    enabled_exts = config.getoption("--enable-extension")
     disabled_exts = config.getoption("--disable-extension")
-    for ext in enabled_exts:
-        if ext in disabled_exts:
-            raise ValueError(f"{ext=} both enabled and disabled")
     for item in items:
-        # enable/disable extensions
+        # disable extensions
         try:
             ext_mark = next(m for m in item.iter_markers() if m.name == "xp_extension")
             ext = ext_mark.args[0]
             if ext in disabled_exts:
                 item.add_marker(
                     mark.skip(reason=f"{ext} disabled in --disable-extensions")
                 )
-            elif ext not in enabled_exts and not xp_has_ext(ext):
+            elif not xp_has_ext(ext):
                 item.add_marker(mark.skip(reason=f"{ext} not found in array module"))
         except StopIteration:
             pass