Check dependencies

src/pip/_internal/commands/check.py

@@ -1,5 +1,5 @@
 import logging
-from optparse import Values
+from optparse import Option, OptionParser, Values
 from typing import Callable, List, Optional
 
 from pip._internal.cli.base_command import Command
@@ -13,6 +13,13 @@
 logger = logging.getLogger(__name__)
 
 
+def _handle_ignore_packages(
+    option: Option, opt_str: str, value: str, parser: OptionParser
+) -> None:
+    assert option.dest is not None
+    setattr(parser.values, option.dest, set(value.split(",")))
+
+
 class CheckCommand(Command):
     """Verify installed packages have compatible dependencies."""
 
@@ -22,10 +29,11 @@ class CheckCommand(Command):
     def add_options(self) -> None:
         self.cmd_opts.add_option(
             "--ignore-packages",
-            action="append",
-            metavar="PACKAGE",
+            action="callback",
+            callback=_handle_ignore_packages,
+            metavar="package",
+            type="str",
             dest="ignore_packages",
-            default=[],
             help="Ignore packages.",
         )
         self.parser.insert_option_group(0, self.cmd_opts)

src/pip/_internal/operations/check.py

@@ -71,6 +71,9 @@ def check_package_set(
         for req in package_detail.dependencies:
             name = canonicalize_name(req.name)
 
+            if should_ignore and should_ignore(name):
+                continue
+
             # Check if it's missing
             if name not in package_set:
                 missed = True

tests/functional/test_check.py

@@ -323,7 +323,7 @@ def test_check_ignore_packages(script: PipTestEnvironment) -> None:
     result = script.pip("install", "--no-index", package_a_path, "--no-deps")
     assert "Successfully installed package-A-1.0" in result.stdout, str(result)
 
-    result = script.pip("check", "--ignore-packages=package-a")
+    result = script.pip("check", "--ignore-packages=missing")
     expected_lines = ("No broken requirements found.",)
     assert matches_expected_lines(result.stdout, expected_lines)
     assert result.returncode == 0