feat: Validate string format 'byte'

Author: thced

src/main/java/com/retailsvc/http/validate/DefaultValidator.java

@@ -27,6 +27,7 @@
 import java.time.OffsetDateTime;
 import java.time.format.DateTimeParseException;
 import java.util.ArrayList;
+import java.util.Base64;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -86,7 +87,8 @@ private record FormatCheck(Predicate<String> isValid, String message) {}
               new FormatCheck(s -> HOSTNAME.matcher(s).matches(), "not a valid hostname")),
           Map.entry("ipv4", new FormatCheck(s -> IPV4.matcher(s).matches(), "not a valid ipv4")),
           Map.entry("ipv6", new FormatCheck(s -> IPV6.matcher(s).matches(), "not a valid ipv6")),
-          Map.entry("regex", new FormatCheck(DefaultValidator::isRegex, "not a valid regex")));
+          Map.entry("regex", new FormatCheck(DefaultValidator::isRegex, "not a valid regex")),
+          Map.entry("byte", new FormatCheck(DefaultValidator::isByte, "not valid base64")));
 
   private final Function<String, Schema> refResolver;
   private final ConcurrentMap<String, Pattern> compiledPatterns = new ConcurrentHashMap<>();
@@ -211,6 +213,15 @@ private static boolean isRegex(String s) {
     }
   }
 
+  private static boolean isByte(String s) {
+    try {
+      Base64.getDecoder().decode(s);
+      return true;
+    } catch (IllegalArgumentException _) {
+      return false;
+    }
+  }
+
   private static boolean isUriReference(String s) {
     try {
       new URI(s);

src/test/java/com/retailsvc/http/validate/StringIntegerNumberTest.java

@@ -197,6 +197,19 @@ void stringFormatRegex() {
         .isEqualTo("format");
   }
 
+  @Test
+  void stringFormatByte() {
+    StringSchema s = new StringSchema(Set.of(TypeName.STRING), null, null, null, "byte", null);
+    assertThatCode(() -> v.validate("aGVsbG8=", s, "/v")).doesNotThrowAnyException();
+    assertThatCode(() -> v.validate("", s, "/v")).doesNotThrowAnyException();
+    assertThatThrownBy(() -> v.validate("not base64!!", s, "/v"))
+        .extracting(t -> ((ValidationException) t).error().keyword())
+        .isEqualTo("format");
+    assertThatThrownBy(() -> v.validate("a===", s, "/v"))
+        .extracting(t -> ((ValidationException) t).error().keyword())
+        .isEqualTo("format");
+  }
+
   @Test
   void stringRejectsNonString() {
     StringSchema s = new StringSchema(Set.of(TypeName.STRING), null, null, null, null, null);