Infer returns from match cases (#2042)

ChangeLog

@@ -15,6 +15,10 @@ Release date: TBA
 
   Refs PyCQA/pylint#7306
 
+* ``astroid`` now infers return values from match cases.
+
+  Refs PyCQA/pylint#5288
+
 * ``Astroid`` now retrieves the default values of keyword only arguments and sets them on
   ``Arguments.kw_defaults``.
 

astroid/nodes/node_classes.py

@@ -4982,7 +4982,7 @@ def _infer(
 # Pattern matching #######################################################
 
 
-class Match(_base_nodes.Statement):
+class Match(_base_nodes.Statement, _base_nodes.MultiLineBlockNode):
     """Class representing a :class:`ast.Match` node.
 
     >>> import astroid
@@ -4998,6 +4998,7 @@ class Match(_base_nodes.Statement):
     """
 
     _astroid_fields = ("subject", "cases")
+    _multi_line_block_fields = ("cases",)
 
     def __init__(
         self,

tests/test_nodes.py

@@ -1947,3 +1947,22 @@ def test_match_class():
             case1.pattern.cls,
             *case1.pattern.kwd_patterns,
         ]
+
+    @staticmethod
+    def test_return_from_match():
+        code = textwrap.dedent(
+            """
+        def return_from_match(x):
+            match x:
+                case 10:
+                    return 10
+                case _:
+                    return -1
+
+        return_from_match(10)  #@
+        """
+        ).strip()
+        node = builder.extract_node(code)
+        inferred = node.inferred()
+        assert len(inferred) == 2
+        assert [inf.value for inf in inferred] == [10, -1]