Merge HtmlCharacterEntityDecoderTests into HtmlUtilsTests

See gh-35711

(cherry picked from commit 0342cd0)

Author: sbrannen

spring-web/src/test/java/org/springframework/web/util/HtmlCharacterEntityDecoderTests.java

@@ -21,14 +21,16 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
+ * Tests for {@link HtmlUtils}.
+ *
  * @author Alef Arendsen
  * @author Martin Kersten
  * @author Rick Evans
  */
 class HtmlUtilsTests {
 
 	@Test
-	void testHtmlEscape() {
+	void htmlEscape() {
 		String unescaped = "\"This is a quote'";
 		String escaped = HtmlUtils.htmlEscape(unescaped);
 		assertThat(escaped).isEqualTo(""This is a quote'");
@@ -39,14 +41,7 @@ void testHtmlEscape() {
 	}
 
 	@Test
-	void testHtmlUnescape() {
-		String escaped = ""This is a quote'";
-		String unescaped = HtmlUtils.htmlUnescape(escaped);
-		assertThat(unescaped).isEqualTo("\"This is a quote'");
-	}
-
-	@Test
-	void testEncodeIntoHtmlCharacterSet() {
+	void htmlEscapeIntoHtmlCharacterSet() {
 		assertThat(HtmlUtils.htmlEscape("")).as("An empty string should be converted to an empty string").isEmpty();
 		assertThat(HtmlUtils.htmlEscape("A sentence containing no special characters.")).as("A string containing no special characters should not be affected").isEqualTo("A sentence containing no special characters.");
 
@@ -60,12 +55,11 @@ void testEncodeIntoHtmlCharacterSet() {
 		assertThat(HtmlUtils.htmlEscapeDecimal("" + (char) 977)).as("The special character 977 should be encoded to 'ϑ'").isEqualTo("ϑ");
 	}
 
-	// SPR-9293
-	@Test
-	void testEncodeIntoHtmlCharacterSetFromUtf8() {
+	@Test  // SPR-9293
+	void htmlEscapeIntoHtmlCharacterSetFromUtf8() {
 		String utf8 = ("UTF-8");
-		assertThat(HtmlUtils.htmlEscape("", utf8)).as("An empty string should be converted to an empty string")
-				.isEmpty();
+
+		assertThat(HtmlUtils.htmlEscape("", utf8)).as("An empty string should be converted to an empty string").isEmpty();
 		assertThat(HtmlUtils.htmlEscape("A sentence containing no special characters.")).as("A string containing no special characters should not be affected").isEqualTo("A sentence containing no special characters.");
 
 		assertThat(HtmlUtils.htmlEscape("< >", utf8)).as("'< >' should be encoded to '&lt; &gt;'").isEqualTo("&lt; &gt;");
@@ -75,7 +69,38 @@ void testEncodeIntoHtmlCharacterSetFromUtf8() {
 	}
 
 	@Test
-	void testDecodeFromHtmlCharacterSet() {
+	void htmlUnescape() {
+		String escaped = "&quot;This is a quote&#39;";
+		String unescaped = HtmlUtils.htmlUnescape(escaped);
+		assertThat(unescaped).isEqualTo("\"This is a quote'");
+	}
+
+	@Test
+	void htmlUnescapeHandlesSupplementaryCharactersAsDecimal() {
+		String expectedCharacter = "😀";
+		String decimalEntity = "&#128512;";
+		String actualResultFromDecimal = HtmlUtils.htmlUnescape(decimalEntity);
+		assertThat(actualResultFromDecimal).as("Decimal entity was not converted correctly.").isEqualTo(expectedCharacter);
+	}
+
+	@Test
+	void htmlUnescapeHandlesSupplementaryCharactersAsHexadecimal() {
+		String expectedCharacter = "😀";
+		String hexEntity = "&#x1F600;";
+		String actualResultFromHex = HtmlUtils.htmlUnescape(hexEntity);
+		assertThat(actualResultFromHex).as("Hexadecimal entity was not converted correctly.").isEqualTo(expectedCharacter);
+	}
+
+	@Test
+	void htmlUnescapeHandlesBasicEntities() {
+		String input = "&lt;p&gt;Tom &amp; Jerry&#39;s &quot;Show&quot;&lt;/p&gt;";
+		String expectedOutput = "<p>Tom & Jerry's \"Show\"</p>";
+		String actualOutput = HtmlUtils.htmlUnescape(input);
+		assertThat(actualOutput).as("Basic HTML entities were not unescaped correctly.").isEqualTo(expectedOutput);
+	}
+
+	@Test
+	void htmlUnescapeFromHtmlCharacterSet() {
 		assertThat(HtmlUtils.htmlUnescape("")).as("An empty string should be converted to an empty string").isEmpty();
 		assertThat(HtmlUtils.htmlUnescape("This is a sentence containing no special characters.")).as("A string containing no special characters should not be affected").isEqualTo("This is a sentence containing no special characters.");