🐛 Fix equality check for custom classes (#979)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>
Co-authored-by: svlandeg <svlandeg@github.com>
Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

tests/test_param_meta_empty.py

@@ -0,0 +1,36 @@
+import typer
+from typer.testing import CliRunner
+
+runner = CliRunner()
+
+
+def test_default_with_class_with_custom_eq():
+    app = typer.Typer()
+
+    from typer.models import ParamMeta
+
+    class StupidClass:
+        def __init__(self, a):
+            self.a = a
+
+        def __eq__(self, other) -> bool:
+            if other is ParamMeta.empty:
+                return True
+            try:
+                return self.a == other.a
+            except Exception:
+                return False
+
+        def __ne__(self, other: object) -> bool:
+            return not self.__eq__(other)
+
+    @app.command()
+    def cmd(val=StupidClass(42)):
+        print(val)
+
+    assert StupidClass(666) == ParamMeta.empty
+    assert StupidClass(666) != StupidClass(1)
+
+    result = runner.invoke(app)
+    assert result.exit_code == 0, result.output
+    assert "StupidClass" in result.output

typer/main.py

@@ -821,14 +821,14 @@ def get_click_param(
             required = True
         else:
             default_value = parameter_info.default
-    elif param.default == Required or param.default == param.empty:
+    elif param.default == Required or param.default is param.empty:
         required = True
         parameter_info = ArgumentInfo()
     else:
         default_value = param.default
         parameter_info = OptionInfo()
     annotation: Any
-    if not param.annotation == param.empty:
+    if param.annotation is not param.empty:
         annotation = param.annotation
     else:
         annotation = str