Reduce visibility of previously internal package (#309)

As part of refactoring, the previous internal package (where the
validator implementation is found) was refactored to the
build.buf.protovalidate package. As part of this change, we should
ensure that all previously internal classes are final (to prevent
subclassing) and that methods not overridden from an interface use
package private or lower visibility.

Author: pkwarren

src/main/java/build/buf/protovalidate/AnyEvaluator.java

@@ -32,7 +32,7 @@
  * com.google.protobuf.Any}'s within an expression, breaking evaluation if the type is unknown at
  * runtime.
  */
-class AnyEvaluator implements Evaluator {
+final class AnyEvaluator implements Evaluator {
   private final RuleViolationHelper helper;
   private final Descriptors.FieldDescriptor typeURLDescriptor;
   private final Set<String> in;

src/main/java/build/buf/protovalidate/AstExpression.java

@@ -22,12 +22,12 @@
 import dev.cel.compiler.CelCompiler;
 
 /** {@link AstExpression} is a compiled CEL {@link CelAbstractSyntaxTree}. */
-class AstExpression {
+final class AstExpression {
   /** The compiled CEL AST. */
-  public final CelAbstractSyntaxTree ast;
+  final CelAbstractSyntaxTree ast;
 
   /** Contains the original expression from the proto file. */
-  public final Expression source;
+  final Expression source;
 
   /** Constructs a new {@link AstExpression}. */
   private AstExpression(CelAbstractSyntaxTree ast, Expression source) {
@@ -43,7 +43,7 @@ private AstExpression(CelAbstractSyntaxTree ast, Expression source) {
    * @return The compiled {@link AstExpression}.
    * @throws CompilationException if the expression compilation fails.
    */
-  public static AstExpression newAstExpression(CelCompiler cel, Expression expr)
+  static AstExpression newAstExpression(CelCompiler cel, Expression expr)
       throws CompilationException {
     CelValidationResult compileResult = cel.compile(expr.expression);
     if (!compileResult.getAllIssues().isEmpty()) {

src/main/java/build/buf/protovalidate/CelPrograms.java

@@ -21,7 +21,7 @@
 import org.jspecify.annotations.Nullable;
 
 /** Evaluator that executes a {@link CompiledProgram}. */
-class CelPrograms implements Evaluator {
+final class CelPrograms implements Evaluator {
   private final RuleViolationHelper helper;
 
   /** A list of {@link CompiledProgram} that will be executed against the input message. */

src/main/java/build/buf/protovalidate/CompiledProgram.java

@@ -25,7 +25,7 @@
  * {@link CompiledProgram} is a parsed and type-checked {@link Program} along with the source {@link
  * Expression}.
  */
-class CompiledProgram {
+final class CompiledProgram {
   /** A compiled CEL program that can be evaluated against a set of variable bindings. */
   private final Program program;
 
@@ -52,7 +52,7 @@ class CompiledProgram {
    * @param rulePath The field path from the FieldRules to the rule value.
    * @param ruleValue The rule value.
    */
-  public CompiledProgram(
+  CompiledProgram(
       Program program,
       Expression source,
       @Nullable FieldPath rulePath,
@@ -74,7 +74,7 @@ public CompiledProgram(
    *     violations.
    * @throws ExecutionException If the evaluation of the CEL program fails with an error.
    */
-  public RuleViolation.@Nullable Builder eval(Value fieldValue, CelVariableResolver variables)
+  RuleViolation.@Nullable Builder eval(Value fieldValue, CelVariableResolver variables)
       throws ExecutionException {
     Object value;
     try {

src/main/java/build/buf/protovalidate/CustomOverload.java

@@ -74,10 +74,11 @@ static List<CelFunctionBinding> create() {
   }
 
   /**
-   * This implementes that standard {@code bytes_to_string} function. We override it because the CEL
+   * This implements that standard {@code bytes_to_string} function. We override it because the CEL
    * library doesn't validate that the bytes are valid utf-8.
    *
-   * <p>Workround until https://github.com/google/cel-java/pull/717 lands.
+   * <p>Workaround until <a href="https://github.com/google/cel-java/pull/717">cel-java issue
+   * 717</a> lands.
    */
   private static CelFunctionBinding celBytesToString() {
     return CelFunctionBinding.from(
@@ -202,9 +203,7 @@ private static CelFunctionBinding celContainsBytes() {
         "contains_bytes",
         ByteString.class,
         ByteString.class,
-        (receiver, param) -> {
-          return bytesContains(receiver.toByteArray(), param.toByteArray());
-        });
+        (receiver, param) -> bytesContains(receiver.toByteArray(), param.toByteArray()));
   }
 
   static boolean bytesContains(byte[] arr, byte[] subArr) {
@@ -285,9 +284,7 @@ private static CelFunctionBinding celIsIpPrefixInt() {
         "is_ip_prefix_int",
         String.class,
         Long.class,
-        (prefix, version) -> {
-          return isIpPrefix(prefix, version, false);
-        });
+        (prefix, version) -> isIpPrefix(prefix, version, false));
   }
 
   /**
@@ -300,9 +297,7 @@ private static CelFunctionBinding celIsIpPrefixBool() {
         "is_ip_prefix_bool",
         String.class,
         Boolean.class,
-        (prefix, strict) -> {
-          return isIpPrefix(prefix, 0L, strict);
-        });
+        (prefix, strict) -> isIpPrefix(prefix, 0L, strict));
   }
 
   /**
@@ -390,9 +385,9 @@ private static CelFunctionBinding celIsHostAndPort() {
    * <p>The host can be one of:
    *
    * <ul>
-   *   <li>An IPv4 address in dotted decimal format, for example "192.168.0.1".
-   *   <li>An IPv6 address enclosed in square brackets, for example "[::1]".
-   *   <li>A hostname, for example "example.com".
+   *   <li>An IPv4 address in dotted decimal format, for example {@code 192.168.0.1}.
+   *   <li>An IPv6 address enclosed in square brackets, for example {@code [::1]}.
+   *   <li>A hostname, for example {@code example.com}.
    * </ul>
    *
    * <p>The port is separated by a colon. It must be non-empty, with a decimal number in the range
@@ -570,7 +565,8 @@ static boolean isIp(String addr, long ver) {
   }
 
   /**
-   * Returns true if the string is a URI, for example "https://example.com/foo/bar?baz=quux#frag".
+   * Returns true if the string is a URI, for example {@code
+   * https://example.com/foo/bar?baz=quux#frag}.
    *
    * <p>URI is defined in the internet standard RFC 3986. Zone Identifiers in IPv6 address literals
    * are supported (RFC 6874).
@@ -580,8 +576,9 @@ private static boolean isUri(String str) {
   }
 
   /**
-   * Returns true if the string is a URI Reference - a URI such as
-   * "https://example.com/foo/bar?baz=quux#frag", or a Relative Reference such as "./foo/bar?query".
+   * Returns true if the string is a URI Reference - a URI such as {@code
+   * https://example.com/foo/bar?baz=quux#frag}, or a Relative Reference such as {@code
+   * ./foo/bar?query}.
    *
    * <p>URI, URI Reference, and Relative Reference are defined in the internet standard RFC 3986.
    * Zone Identifiers in IPv6 address literals are supported (RFC 6874).

src/main/java/build/buf/protovalidate/DescriptorMappings.java

@@ -105,7 +105,7 @@ private DescriptorMappings() {}
    * @return The rules field descriptor for the specified wrapper fully qualified name.
    */
   @Nullable
-  public static FieldDescriptor expectedWrapperRules(String fqn) {
+  static FieldDescriptor expectedWrapperRules(String fqn) {
     switch (fqn) {
       case "google.protobuf.BoolValue":
         return EXPECTED_STANDARD_RULES.get(FieldDescriptor.Type.BOOL);
@@ -136,7 +136,7 @@ public static FieldDescriptor expectedWrapperRules(String fqn) {
    * @param kind The protobuf field type.
    * @return The corresponding CEL type for the protobuf field.
    */
-  public static CelType protoKindToCELType(FieldDescriptor.Type kind) {
+  static CelType protoKindToCELType(FieldDescriptor.Type kind) {
     switch (kind) {
       case FLOAT:
       case DOUBLE:

src/main/java/build/buf/protovalidate/EmbeddedMessageEvaluator.java

@@ -18,7 +18,7 @@
 import java.util.Collections;
 import java.util.List;
 
-class EmbeddedMessageEvaluator implements Evaluator {
+final class EmbeddedMessageEvaluator implements Evaluator {
   private final RuleViolationHelper helper;
   private final MessageEvaluator messageEvaluator;
 

src/main/java/build/buf/protovalidate/EnumEvaluator.java

@@ -28,7 +28,7 @@
  * {@link EnumEvaluator} checks an enum value being a member of the defined values exclusively. This
  * check is handled outside CEL as enums are completely type erased to integers.
  */
-class EnumEvaluator implements Evaluator {
+final class EnumEvaluator implements Evaluator {
   private final RuleViolationHelper helper;
 
   /** Captures all the defined values for this enum */

src/main/java/build/buf/protovalidate/EvaluatorBuilder.java

@@ -43,7 +43,7 @@
 import org.jspecify.annotations.Nullable;
 
 /** A build-through cache of message evaluators keyed off the provided descriptor. */
-class EvaluatorBuilder {
+final class EvaluatorBuilder {
   private static final FieldPathElement CEL_FIELD_PATH_ELEMENT =
       FieldPathUtils.fieldPathElement(
           FieldRules.getDescriptor().findFieldByNumber(FieldRules.CEL_FIELD_NUMBER));
@@ -150,8 +150,7 @@ private DescriptorCacheBuilder(
      * @return Unmodifiable map of descriptors to evaluators.
      * @throws CompilationException If an error occurs compiling a rule on the cache.
      */
-    public Map<Descriptor, MessageEvaluator> build(Descriptor descriptor)
-        throws CompilationException {
+    Map<Descriptor, MessageEvaluator> build(Descriptor descriptor) throws CompilationException {
       createMessageEvaluator(descriptor);
       return Collections.unmodifiableMap(cache);
     }

src/main/java/build/buf/protovalidate/Expression.java

@@ -19,15 +19,15 @@
 import java.util.List;
 
 /** Expression represents a single CEL expression. */
-class Expression {
+final class Expression {
   /** The id of the rule. */
-  public final String id;
+  final String id;
 
   /** The message of the rule. */
-  public final String message;
+  final String message;
 
   /** The expression of the rule. */
-  public final String expression;
+  final String expression;
 
   /**
    * Constructs a new Expression.
@@ -57,7 +57,7 @@ private Expression(Rule rule) {
    * @param rules The list of rules.
    * @return The list of expressions.
    */
-  public static List<Expression> fromRules(List<build.buf.validate.Rule> rules) {
+  static List<Expression> fromRules(List<build.buf.validate.Rule> rules) {
     List<Expression> expressions = new ArrayList<>();
     for (build.buf.validate.Rule rule : rules) {
       expressions.add(new Expression(rule));