Add support for Java 21

Author: phuongnq

handlebars/src/test/java/com/github/jknack/handlebars/AbstractTest.java

@@ -34,6 +34,19 @@ public void shouldCompileTo(final String template, final String data, final Stri
     shouldCompileTo(template, data, expected, "");
   }
 
+  /**
+   * Normalizes spaces in the result and compares it with the expected value.
+   *
+   * @param template The template to compile.
+   * @param data The context to apply.
+   * @param expected The expected result.
+   * @throws IOException If an I/O error occurs.
+   */
+  public void shouldCompileToNormalized(final String template, final Object data, final String expected)
+      throws IOException {
+    shouldCompileToNormalized(template, data, new Hash(), new Hash(), expected, "");
+  }
+
   public void shouldCompileTo(final String template, final Object data, final String expected)
       throws IOException {
     shouldCompileTo(template, data, expected, "");
@@ -120,6 +133,41 @@ public void shouldCompileTo(
     assertEquals(expected, result, "'" + expected + "' should === '" + result + "': " + message);
   }
 
+  /*
+   * Normalizes spaces in the result and compares it with the expected value.
+   *
+   * @param template The template to compile.
+   * @param context The context to apply.
+   * @param helpers The helpers to use.
+   * @param partials The partials to use.
+   * @param expected The expected result.
+   * @param message The message to display on failure.
+   * @throws IOException If an I/O error occurs.
+   */
+  public void shouldCompileToNormalized(
+      final String template,
+      final Object context,
+      final Hash helpers,
+      final Hash partials,
+      final String expected,
+      final String message)
+      throws IOException {
+    Template t = compile(template, helpers, partials);
+    String result = t.apply(configureContext(context));
+    assertEquals(expected, normalizeSpaces(result), "'" + expected + "' should === '" + result + "': " + message);
+  }
+
+  /**
+   * Helper to normalize narrow no-break space (U+202F) and regular non-breaking space (U+00A0)
+   * characters to regular space (U+0020).
+   */
+  public String normalizeSpaces(String input) {
+    return input.replace('\u202F', ' ')
+                .replace('\u00A0', ' ')
+                .replaceAll("\\s+", " ")  // optional: also collapses multiple spaces
+                .trim();
+  }
+
   protected Object configureContext(final Object context) {
     return context;
   }

pom.xml

@@ -502,9 +502,9 @@
     <maven.build.timestamp.format>yyyy-MM-dd HH:mm:ssa</maven.build.timestamp.format>
     <maven-antrun-plugin.version>3.1.0</maven-antrun-plugin.version>
     <timestamp>${maven.build.timestamp}</timestamp>
-    <maven.compiler.source>17</maven.compiler.source>
-    <maven.compiler.target>17</maven.compiler.target>
-    <maven.compiler.release>17</maven.compiler.release>
+    <maven.compiler.source>21</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
+    <maven.compiler.release>21</maven.compiler.release>
     <maven.javadoc.failOnError>false</maven.javadoc.failOnError>
     <pre-commit-hook>src${file.separator}etc${file.separator}formatter.sh</pre-commit-hook>
     <mustache-specs>handlebars${file.separator}src${file.separator}test${file.separator}resources${file.separator}mustache</mustache-specs>

tests/src/test/java/com/github/jknack/handlebars/helper/ext/JodaHelperTest.java

@@ -60,8 +60,11 @@ public void testStyle() throws IOException {
         version -> version <= 8,
         () -> shouldCompileTo("{{jodaStyleHelper this \"SS\"}}", dateTime, "7/4/95 2:32 PM"));
     withJava(
-        version -> version >= 9,
+        version -> version >= 9 && version <= 20,
         () -> shouldCompileTo("{{jodaStyleHelper this \"SS\"}}", dateTime, "7/4/95, 2:32 PM"));
+    withJava(
+        version -> version >= 21,
+        () -> shouldCompileToNormalized("{{jodaStyleHelper this \"SS\"}}", dateTime, "7/4/95, 2:32 PM"));
   }
 
   @Test