xplat/js/react-native-github/packages/react-native/ReactCommon/react/renderer/attributedstring/ParagraphAttributes.cpp

Reviewed By: cortinico

Differential Revision: D110867849

Author: DevmateUtgenCppGeneralFBOrg Bot

packages/react-native/ReactCommon/react/renderer/attributedstring/tests/ParagraphAttributesTest.cpp

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+#include <react/renderer/attributedstring/ParagraphAttributes.h>
+
+namespace facebook::react {
+
+// The three Float fields default to NaN, and NaN != NaN under IEEE-754.
+// operator== must special-case NaN via floatEquality so two freshly
+// default-constructed ParagraphAttributes compare equal.
+TEST(
+    ParagraphAttributesTest,
+    testOperatorEqualsDefaultConstructedInstancesAreEqual) {
+  ParagraphAttributes a{};
+  ParagraphAttributes b{};
+
+  EXPECT_TRUE(a == b);
+}
+
+// operator== compares Float fields with an epsilon tolerance (0.005) rather
+// than an exact ==. Differences below the epsilon must still compare equal;
+// differences well above the epsilon must compare unequal.
+TEST(
+    ParagraphAttributesTest,
+    testOperatorEqualsFloatFieldsUseEpsilonComparison) {
+  ParagraphAttributes a{};
+  a.minimumFontSize = 12.0f;
+  a.maximumFontSize = 48.0f;
+  a.minimumFontScale = 0.5f;
+  auto b = a;
+
+  b.minimumFontSize = a.minimumFontSize + 0.001f;
+  b.maximumFontSize = a.maximumFontSize + 0.001f;
+  b.minimumFontScale = a.minimumFontScale + 0.001f;
+  EXPECT_TRUE(a == b);
+
+  b = a;
+  b.minimumFontSize = a.minimumFontSize + 1.0f;
+  EXPECT_FALSE(a == b);
+}
+
+// floatEquality returns true only when *both* operands are NaN or when
+// *neither* is. A NaN-vs-finite mismatch in any of the three float fields
+// must therefore make the instances unequal, even though both operands are
+// "invalid" font sizes.
+TEST(
+    ParagraphAttributesTest,
+    testOperatorEqualsNaNVsFiniteFloatComparesUnequal) {
+  ParagraphAttributes withNaN{};
+  ParagraphAttributes withFinite{};
+  withFinite.minimumFontSize = 12.0f;
+
+  EXPECT_FALSE(withNaN == withFinite);
+}
+
+// textAlignVertical is a std::optional; operator== must treat "unset" and
+// "set" as distinct, independent of the wrapped value.
+TEST(
+    ParagraphAttributesTest,
+    testOperatorEqualsHandlesOptionalTextAlignVerticalSetVsUnset) {
+  ParagraphAttributes unset{};
+  ParagraphAttributes set{};
+  set.textAlignVertical = TextAlignmentVertical::Auto;
+
+  EXPECT_FALSE(unset == set);
+}
+
+} // namespace facebook::react