Fix #575: Scope IParametersValidator to Object-Specific Parameters

src/main/java/com/beust/jcommander/JCommander.java

@@ -129,9 +129,12 @@ public void addValue(Object convertedValue) {
     private Map<Parameterized, ParameterDescription> requiredFields = Maps.newHashMap();
 
     /**
-     * A set of all the parameters validators to be applied.
+     * A map of objects to their associated parameter validators. Each key is an object containing
+     * fields annotated with {@link Parameter}, and the value is a set of {@link IParametersValidator}
+     * instances that validate the parameters specific to that object. This ensures validators
+     * are scoped to their respective object's parameters rather than all parameters globally.
      */
-    private Set<IParametersValidator> parametersValidators = Sets.newHashSet();
+    private final Map<Object, Set<IParametersValidator>> objectValidators = Maps.newHashMap();
 
     /**
      * A map of all the parameterized fields/methods.
@@ -425,14 +428,19 @@ private void validateOptions() {
             }
         }
 
-        Map<String, Object> nameValuePairs = Maps.newHashMap();
-        fields.values().forEach(pd ->
-            nameValuePairs.put(pd.getLongestName(), pd.getValue())
-        );
+        // Group parameters by their owning object
+        final Map<Object, Map<String, Object>> objectParameters = Maps.newHashMap();
+        fields.values().forEach(pd -> {
+            Object owner = pd.getObject();
+            Map<String, Object> params = objectParameters.computeIfAbsent(owner, k -> Maps.newHashMap());
+            params.put(pd.getLongestName(), pd.getValue());
+        });
 
-        parametersValidators.forEach(parametersValidator ->
-            parametersValidator.validate(nameValuePairs)
-        );
+        // Apply validators for each object
+        objectValidators.forEach((object, validators) -> {
+            Map<String, Object> params = objectParameters.getOrDefault(object, Maps.newHashMap());
+            validators.forEach(validator -> validator.validate(params));
+        });
     }
 
     private static String pluralize(int quantity, String singular, String plural) {
@@ -619,13 +627,16 @@ private void addDescription(Object object) {
 
         Parameters parameters = cls.getAnnotation(Parameters.class);
         if (parameters != null) {
-            Class<? extends IParametersValidator>[] parametersValidatorClasses = parameters.parametersValidators();
-                for (Class<? extends IParametersValidator> parametersValidatorClass : parametersValidatorClasses) {
-                try {
-                    IParametersValidator parametersValidator = parametersValidatorClass.getDeclaredConstructor().newInstance();
-                    parametersValidators.add(parametersValidator);
-                } catch (ReflectiveOperationException e) {
-                    throw new ParameterException("Cannot instantiate rule: " + parametersValidatorClass, e);
+            final Class<? extends IParametersValidator>[] parametersValidatorClasses = parameters.parametersValidators();
+            if (parametersValidatorClasses.length > 0) {
+                Set<IParametersValidator> validators = objectValidators.computeIfAbsent(object, k -> Sets.newHashSet());
+                for (final Class<? extends IParametersValidator> parametersValidatorClass : parametersValidatorClasses) {
+                    try {
+                        final IParametersValidator parametersValidator = parametersValidatorClass.getDeclaredConstructor().newInstance();
+                        validators.add(parametersValidator);
+                    } catch (ReflectiveOperationException e) {
+                        throw new ParameterException("Cannot instantiate rule: " + parametersValidatorClass, e);
+                    }
                 }
             }
         }

src/test/java/com/beust/jcommander/Issue575ValidatorScopeTest.java

@@ -0,0 +1,77 @@
+package com.beust.jcommander;
+
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+import java.util.Map;
+
+public class Issue575ValidatorScopeTest {
+
+    @Parameters(parametersValidators = MyValidator.class)
+    static class SubGroup {
+        @Parameter(names = "--arg1")
+        private boolean arg1;
+
+        @Parameter(names = "--arg2")
+        private String arg2;
+
+        public boolean isArg1() {
+            return arg1;
+        }
+
+        public String getArg2() {
+            return arg2;
+        }
+    }
+
+    static class ArgsTop {
+        @Parameter(names = "--argtop")
+        private boolean argtop;
+
+        @ParametersDelegate
+        private SubGroup subGroup = new SubGroup();
+
+        public boolean isArgtop() {
+            return argtop;
+        }
+    }
+
+    static class MyValidator implements IParametersValidator {
+        @Override
+        public void validate(Map<String, Object> params) throws ParameterException {
+            if (params.containsKey("--argtop")) {
+                throw new ParameterException("Validator should not see --argtop, but found it in: " + params.keySet());
+            }
+            if (!params.containsKey("--arg1") || !params.containsKey("--arg2")) {
+                throw new ParameterException("Validator should see --arg1 and --arg2, but found: " + params.keySet());
+            }
+        }
+    }
+
+    // Pre-fix: Expect exception due to bug (passes with original JCommander)
+    @Test(expectedExceptions = ParameterException.class, expectedExceptionsMessageRegExp = ".*Validator should not see --argtop.*")
+    public void testValidatorScopeBug() {
+        ArgsTop args = new ArgsTop();
+        JCommander jCommander = JCommander.newBuilder()
+                .addObject(args)
+                .build();
+        jCommander.parse("--argtop", "--arg1", "--arg2", "value");
+        // These won’t run pre-fix due to exception
+        Assert.assertTrue(args.isArgtop(), "--argtop should be set");
+        Assert.assertTrue(args.subGroup.isArg1(), "--arg1 should be set");
+        Assert.assertEquals(args.subGroup.getArg2(), "value", "--arg2 should be set");
+    }
+
+    // Post-fix: Expect no exception, verify parameters (passes with fixed JCommander)
+    @Test
+    public void testValidatorScopeFixed() {
+        ArgsTop args = new ArgsTop();
+        JCommander jCommander = JCommander.newBuilder()
+                .addObject(args)
+                .build();
+        jCommander.parse("--argtop", "--arg1", "--arg2", "value");
+        Assert.assertTrue(args.isArgtop(), "--argtop should be set");
+        Assert.assertTrue(args.subGroup.isArg1(), "--arg1 should be set");
+        Assert.assertEquals(args.subGroup.getArg2(), "value", "--arg2 should be set");
+    }
+}