Add tests for MaskedTextBoxTextEditorDropDown.cs

src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/MaskedTextBoxTextEditorDropDownTests.cs

@@ -0,0 +1,59 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable enable
+
+namespace System.Windows.Forms.Design.Tests;
+
+public class MaskedTextBoxTextEditorDropDownTests
+{
+ [Fact]
+ public void Value_ReturnsNull_WhenCancelled()
+ {
+ using MaskedTextBox maskedTextBox = new();
+ using MaskedTextBoxTextEditorDropDown dropDown = new(maskedTextBox);
+ dropDown.TestAccessor().Dynamic._cancel = true;
+
+ dropDown.Value.Should().BeNull();
+ }
+
+ [Fact]
+ public void Value_ReturnsText_WhenNotCancelled()
+ {
+ using MaskedTextBox maskedTextBox = new("00000");
+ maskedTextBox.Text = "12345";
+ using MaskedTextBoxTextEditorDropDown dropDown = new(maskedTextBox);
+ dropDown.TestAccessor().Dynamic._cancel = false;
+
+ dropDown.Value.Should().Be("12345");
+ }
+
+ [Fact]
+ public void ProcessDialogKey_SetsCancel_WhenEscapePressed()
+ {
+ using MaskedTextBox maskedTextBox = new();
+ using MaskedTextBoxTextEditorDropDown dropDown = new(maskedTextBox);
+ bool processDialogKey = dropDown.TestAccessor().Dynamic.ProcessDialogKey(Keys.Escape);
+ bool cancel= dropDown.TestAccessor().Dynamic._cancel;
+
+ cancel.Should().BeTrue();
+ processDialogKey.Should().BeFalse();
+ }
+
+ [Fact]
+ public void MaskInputRejected_SetsError_WhenInputRejected()
+ {
+ using MaskedTextBox maskedTextBox = new("00：00");
+ using MaskedTextBoxTextEditorDropDown dropDown = new(maskedTextBox);
+ using ErrorProvider errorProvider = dropDown.TestAccessor().Dynamic._errorProvider;
+
+ // No error when setting a correct format value.
+ MaskedTextBox dropDownMaskedTextBox = dropDown.TestAccessor().Dynamic._cloneMtb;
+ dropDownMaskedTextBox.Text = "12：20";
+ errorProvider.GetError(dropDownMaskedTextBox).Should().Be(string.Empty);
+
+ // Incorrectly formatted values will result in the error "Error at position 0: expected number".
+ dropDownMaskedTextBox.Text = "invalid";
+ errorProvider.GetError(dropDownMaskedTextBox).Should().Contain(SR.MaskedTextBoxHintDigitExpected);
+ }
+}