test: add more unit tests.

README.md

@@ -1603,3 +1603,86 @@ To register your own default Transformer, add it to a file in `META-INF\services
 the annotation `@ConfigPriority(100)`, specifies the descending priority order to check your transformer when a substitution has been made without specifying the source ${key}
 
 
+# Result Processors
+
+Result Processors are used to modify the result of getting a configuration and decoding it.
+Each processor has an annotation `@ConfigPriority` so we run them in order passing the output of one Result Processor as the input to the next. 
+
+Gestalt has two core result processors `ErrorResultProcessor` and `DefaultResultProcessor`.
+The `ErrorResultProcessor` throws a `GestaltException` if there is an unrecoverable error. 
+The `DefaultResultProcessor` will convert the result into a default value if there is no result. 
+
+To implement your own Result Processors you need to inherit from ResultProcessor.
+
+To automatically register your own default `ResultProcessor`, add it to a file in `META-INF\services\org.github.gestalt.config.processor.result.ResultProcessor` and add the full package of classpath your `ResultProcessor`. 
+
+Alternatively, you can implement the interface and register it with the gestalt builder `addResultProcessors(List<ResultProcessor> resultProcessorSet)`.
+
+```java
+public interface ResultProcessor {
+
+  /**
+   * If your Result Processor needs access to the Gestalt Config.
+   *
+   * @param config Gestalt configuration
+   */
+  default void applyConfig(GestaltConfig config) {}
+
+  /**
+   * Returns the {@link GResultOf} with any processed results.
+   * You can modify the results, errors or any combination.
+   * If your post processor does nothing to the node, return the original node.
+   *
+   * @param results GResultOf to process.
+   * @param path path the object was located at
+   * @param isOptional if the result is optional (an Optional or has a default.
+   * @param defaultVal value to return in the event of failure.
+   * @param klass the type of object.
+   * @param tags any tags used to retrieve te object
+   * @return The validation results with either errors or a successful  obj.
+   * @param <T> Class of the object.
+   * @throws GestaltException for any exceptions while processing the results, such as if there are errors in the result.
+   */
+  <T> GResultOf<T> processResults(GResultOf<T> results, String path, boolean isOptional, 
+                                  T defaultVal, TypeCapture<T> klass, Tags tags)
+    throws GestaltException;
+}
+```
+
+## Validation
+Validations are implemented as a Result Processor as well in `ValidationResultProcessor`.
+To ensure a simple API for validations it does not use the ResultProcessor interface but a `ConfigValidator` interface. 
+
+To automatically register your own default `ConfigValidator`, add it to a file in `META-INF\services\org.github.gestalt.config.processor.result.validation.ConfigValidator` and add the full package of classpath `ConfigValidator`. This is how `gestalt-validator-hibernate` automatically is discovered. 
+
+Alternatively, you can implement the interface and register it with the gestalt builder `addValidators(List<ConfigValidator> validatorsSet)`.  
+
+```java
+/**
+ * Interface for validating objects.
+ *
+ *  @author <a href="mailto:colin.redmond@outlook.com"> Colin Redmond </a> (c) 2024.
+ */
+public interface ConfigValidator {
+
+    /**
+     * If your Validator needs access to the Gestalt Config.
+     *
+     * @param config Gestalt configuration
+     */
+    default void applyConfig(GestaltConfig config) {}
+
+    /**
+     * Returns the {@link GResultOf} with the validation results. If the object is ok it will return the result with no errors.
+     * If there are validation errors they will be returned.
+     *
+     * @param obj object to validate.
+     * @param path path the object was located at
+     * @param klass the type of object.
+     * @param tags any tags used to retrieve te object
+     * @return The validation results with either errors or a successful  obj.
+     * @param <T> Class of the object.
+     */
+    <T> GResultOf<T> validator(T obj, String path, TypeCapture<T> klass, Tags tags);
+}
+```

gestalt-core/src/main/java/module-info.java

@@ -32,10 +32,10 @@
     exports org.github.gestalt.config.tag;
     exports org.github.gestalt.config.token;
     exports org.github.gestalt.config.utils;
-    exports org.github.gestalt.config.processor.result;
     exports org.github.gestalt.config.processor.config;
     exports org.github.gestalt.config.processor.config.transform;
     exports org.github.gestalt.config.processor.config.transform.substitution;
+    exports org.github.gestalt.config.processor.result;
     exports org.github.gestalt.config.processor.result.validation;
 
     provides org.github.gestalt.config.decoder.Decoder with

gestalt-core/src/main/java/org/github/gestalt/config/builder/GestaltBuilder.java

@@ -503,12 +503,9 @@ public GestaltBuilder addPathMappers(List<PathMapper> pathMappers) throws Gestal
      *
      * @param observationRecorders list of observationRecorders to record observations to.
      * @return GestaltBuilder builder
-     * @throws GestaltConfigurationException exception if there are no ObservationRecorder
      */
-    public GestaltBuilder setObservationsRecorders(List<ObservationRecorder> observationRecorders) throws GestaltConfigurationException {
-        if (observationRecorders == null || observationRecorders.isEmpty()) {
-            throw new GestaltConfigurationException("No ObservationRecorder provided while setting");
-        }
+    public GestaltBuilder setObservationsRecorders(List<ObservationRecorder> observationRecorders) {
+        Objects.requireNonNull(observationRecorders, "No ObservationRecorder provided while setting");
         this.observationRecorders = observationRecorders;
 
         return this;
@@ -519,9 +516,8 @@ public GestaltBuilder setObservationsRecorders(List<ObservationRecorder> observa
      *
      * @param observationRecordersSet list of ObservationRecorder to add.
      * @return GestaltBuilder builder
-     * @throws GestaltConfigurationException no ObservationRecorder provided
      */
-    public GestaltBuilder addObservationsRecorders(List<ObservationRecorder> observationRecordersSet) throws GestaltConfigurationException {
+    public GestaltBuilder addObservationsRecorders(List<ObservationRecorder> observationRecordersSet) {
         Objects.requireNonNull(observationRecordersSet, "ObservationRecorder should not be null");
 
         observationRecorders.addAll(observationRecordersSet);
@@ -546,12 +542,9 @@ public GestaltBuilder addObservationsRecorder(ObservationRecorder observationRec
      *
      * @param configValidators list of Validator to validate objects.
      * @return GestaltBuilder builder
-     * @throws GestaltConfigurationException exception if there are no Validator
      */
-    public GestaltBuilder setValidators(List<ConfigValidator> configValidators) throws GestaltConfigurationException {
-        if (configValidators == null || configValidators.isEmpty()) {
-            throw new GestaltConfigurationException("No Validators provided while setting");
-        }
+    public GestaltBuilder setValidators(List<ConfigValidator> configValidators) {
+        Objects.requireNonNull(configValidators, "No Validators provided while setting");
         this.configValidators = configValidators;
 
         return this;
@@ -588,12 +581,9 @@ public GestaltBuilder addValidator(ConfigValidator configValidator) {
      *
      * @param resultProcessors list of resultProcessors.
      * @return GestaltBuilder builder
-     * @throws GestaltConfigurationException exception if there are no ResultProcessor
      */
-    public GestaltBuilder setResultProcessor(List<ResultProcessor> resultProcessors) throws GestaltConfigurationException {
-        if (resultProcessors == null || resultProcessors.isEmpty()) {
-            throw new GestaltConfigurationException("No ResultProcessor provided while setting");
-        }
+    public GestaltBuilder setResultProcessor(List<ResultProcessor> resultProcessors) {
+        Objects.requireNonNull(resultProcessors, "ResultProcessor should not be null");
         this.resultProcessors = resultProcessors;
 
         return this;
@@ -604,9 +594,8 @@ public GestaltBuilder setResultProcessor(List<ResultProcessor> resultProcessors)
      *
      * @param resultProcessorSet list of ResultProcessor to add.
      * @return GestaltBuilder builder
-     * @throws GestaltConfigurationException no ResultProcessor provided
      */
-    public GestaltBuilder addResultProcessors(List<ResultProcessor> resultProcessorSet) throws GestaltConfigurationException {
+    public GestaltBuilder addResultProcessors(List<ResultProcessor> resultProcessorSet) {
         Objects.requireNonNull(resultProcessorSet, "ResultProcessor should not be null");
 
         resultProcessors.addAll(resultProcessorSet);
@@ -939,9 +928,11 @@ public GestaltBuilder setValidationEnabled(Boolean validationEnabled) {
      * If they are not added you will get strange and possible incorrect behaviour.
      *
      * @param addCoreResultProcessors add a core result processor.
+     * @return GestaltBuilder builder
      */
-    public void setAddCoreResultProcessors(boolean addCoreResultProcessors) {
+    public GestaltBuilder setAddCoreResultProcessors(boolean addCoreResultProcessors) {
         this.addCoreResultProcessors = addCoreResultProcessors;
+        return this;
     }
 
     /**

gestalt-core/src/main/java/org/github/gestalt/config/processor/result/ResultProcessor.java

@@ -14,7 +14,7 @@
 public interface ResultProcessor {
 
     /**
-     * If your Validator needs access to the Gestalt Config.
+     * If your Result Processor needs access to the Gestalt Config.
      *
      * @param config Gestalt configuration
      */

gestalt-core/src/main/java/org/github/gestalt/config/processor/result/validation/ValidationResultProcessor.java

@@ -12,6 +12,7 @@
 import org.github.gestalt.config.utils.ClassUtils;
 import org.github.gestalt.config.utils.GResultOf;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.ServiceLoader;
 import java.util.stream.Collectors;
@@ -24,11 +25,12 @@ public class ValidationResultProcessor implements ResultProcessor {
 
     private GestaltConfig gestaltConfig;
     private ObservationManager observationManager;
-    private List<ConfigValidator> configValidators;
+    private final List<ConfigValidator> configValidators;
 
     public ValidationResultProcessor() {
+        configValidators = new ArrayList<>();
         ServiceLoader<ConfigValidator> loader = ServiceLoader.load(ConfigValidator.class);
-        loader.forEach(it -> configValidators.add(it));
+        loader.forEach(configValidators::add);
     }
 
     public ValidationResultProcessor(List<ConfigValidator> configValidators, ObservationManager observationManager) {
@@ -80,7 +82,7 @@ private <T> boolean shouldValidate(TypeCapture<T> klass) {
     }
 
     private <T> void updateValidationObservations(List<ValidationError> errors) {
-        if (gestaltConfig != null && gestaltConfig.isObservationsEnabled() && observationManager != null && !errors.isEmpty()) {
+        if (gestaltConfig != null && gestaltConfig.isObservationsEnabled() && observationManager != null) {
             observationManager.recordObservation("get.config.validation.error", errors.size(), Tags.of());
         }
     }

gestalt-core/src/test/java/org/github/gestalt/config/builder/GestaltBuilderTest.java

@@ -19,10 +19,13 @@
 import org.github.gestalt.config.path.mapper.DotNotationPathMapper;
 import org.github.gestalt.config.path.mapper.PathMapper;
 import org.github.gestalt.config.path.mapper.StandardPathMapper;
+import org.github.gestalt.config.processor.TestValidationProcessor;
 import org.github.gestalt.config.processor.config.ConfigNodeProcessor;
 import org.github.gestalt.config.processor.config.ConfigNodeProcessorConfig;
 import org.github.gestalt.config.processor.config.transform.EnvironmentVariablesTransformer;
 import org.github.gestalt.config.processor.config.transform.StringSubstitutionConfigNodeProcessor;
+import org.github.gestalt.config.processor.result.DefaultResultProcessor;
+import org.github.gestalt.config.processor.result.ErrorResultProcessor;
 import org.github.gestalt.config.reflect.TypeCapture;
 import org.github.gestalt.config.reload.TimedConfigReloadStrategy;
 import org.github.gestalt.config.source.ConfigSource;
@@ -120,6 +123,10 @@ public void build() throws GestaltException {
             .addResultProcessors(List.of(new TestResultProcessor(true)))
             .setResultProcessor(List.of(new TestResultProcessor(true)))
             .setResultsProcessorManager(new ResultsProcessorManager(new ArrayList<>()))
+            .setAddCoreResultProcessors(true)
+            .addValidator(new TestValidationProcessor(true))
+            .addValidators(List.of(new TestValidationProcessor(true)))
+            .setValidators(List.of(new TestValidationProcessor(true)))
             .setSecurityMaskingRule(new HashSet<>())
             .addSecurityMaskingRule("secret")
             .setSecurityMask("&&&&")
@@ -822,6 +829,68 @@ public void manuallyAddedPathMapperConfig() throws GestaltException {
         Assertions.assertEquals(1, mapper3.configCount);
     }
 
+    @Test
+    public void buildWithResultProcessorManager() throws GestaltException {
+        Map<String, String> configs = new HashMap<>();
+        configs.put("db.name", "test");
+        configs.put("db.port", "3306");
+        configs.put("admin[0]", "John");
+        configs.put("admin[1]", "Steve");
+
+        Map<String, String> configs2 = new HashMap<>();
+        configs2.put("db.name", "test2");
+        configs2.put("db.password", "pass");
+        configs2.put("admin[0]", "John2");
+        configs2.put("admin[1]", "Steve2");
+
+        List<ConfigSourcePackage> sources = new ArrayList<>();
+        sources.add(MapConfigSourceBuilder.builder().setCustomConfig(configs).build());
+        sources.add(MapConfigSourceBuilder.builder().setCustomConfig(configs2).build());
+
+        GestaltBuilder builder = new GestaltBuilder();
+        Gestalt gestalt = builder
+            .addSources(sources)
+            .setResultsProcessorManager(new ResultsProcessorManager(List.of(new ErrorResultProcessor(), new DefaultResultProcessor())))
+            .build();
+
+        gestalt.loadConfigs();
+        Assertions.assertEquals("pass", gestalt.getConfig("db.password", String.class));
+        Assertions.assertEquals("test2", gestalt.getConfig("db.name", String.class));
+        Assertions.assertEquals("3306", gestalt.getConfig("db.port", String.class));
+    }
+
+    @Test
+    public void buildWithNoResultProcessorManager() throws GestaltException {
+        Map<String, String> configs = new HashMap<>();
+        configs.put("db.name", "test");
+        configs.put("db.port", "3306");
+        configs.put("admin[0]", "John");
+        configs.put("admin[1]", "Steve");
+
+        Map<String, String> configs2 = new HashMap<>();
+        configs2.put("db.name", "test2");
+        configs2.put("db.password", "pass");
+        configs2.put("admin[0]", "John2");
+        configs2.put("admin[1]", "Steve2");
+
+        List<ConfigSourcePackage> sources = new ArrayList<>();
+        sources.add(MapConfigSourceBuilder.builder().setCustomConfig(configs).build());
+        sources.add(MapConfigSourceBuilder.builder().setCustomConfig(configs2).build());
+
+        GestaltBuilder builder = new GestaltBuilder();
+        Gestalt gestalt = builder
+            .addSources(sources)
+            .setAddCoreResultProcessors(false)
+            .useCacheDecorator(false)
+            .build();
+
+        gestalt.loadConfigs();
+        Assertions.assertEquals("pass", gestalt.getConfig("db.password", String.class));
+        Assertions.assertEquals("test2", gestalt.getConfig("db.name", String.class));
+        Assertions.assertEquals("3306", gestalt.getConfig("db.port", String.class));
+        Assertions.assertNull(gestalt.getConfig("db.none", "default", String.class));
+    }
+
     private static class TestDecoder implements Decoder {
 
         public int configCount = 0;

gestalt-core/src/test/java/org/github/gestalt/config/processor/ResultsProcessorManagerTest.java

@@ -152,4 +152,26 @@ public String description() {
         Assertions.assertEquals("something broke", results.getErrors().get(0).description());
     }
 
+    @Test
+    public void testTwoResultProcessorResultHasError2() throws GestaltException {
+        var validationManager = new ResultsProcessorManager(List.of(
+            new TestResultProcessor(false), new TestResultProcessor(false), new TestResultProcessor3(false)));
+
+        var results = validationManager.processResults(GResultOf.errors(new ValidationError(ValidationLevel.ERROR) {
+                @Override
+                public String description() {
+                    return "there was an error";
+                }
+            }), "my.path", false, null,
+            TypeCapture.of(String.class), Tags.of());
+
+        Assertions.assertFalse(results.hasResults());
+        Assertions.assertTrue(results.hasErrors());
+
+        Assertions.assertEquals(1, results.getErrors().size());
+
+        Assertions.assertEquals(ValidationLevel.ERROR, results.getErrors().get(0).level());
+        Assertions.assertEquals("something broke", results.getErrors().get(0).description());
+    }
+
 }

gestalt-core/src/test/java/org/github/gestalt/config/processor/TestResultProcessor3.java

@@ -0,0 +1,32 @@
+package org.github.gestalt.config.processor;
+
+import org.github.gestalt.config.entity.ValidationError;
+import org.github.gestalt.config.entity.ValidationLevel;
+import org.github.gestalt.config.processor.result.ResultProcessor;
+import org.github.gestalt.config.reflect.TypeCapture;
+import org.github.gestalt.config.tag.Tags;
+import org.github.gestalt.config.utils.GResultOf;
+
+public class TestResultProcessor3 implements ResultProcessor {
+
+    public boolean isOk = true;
+
+    public TestResultProcessor3(boolean isOk) {
+        this.isOk = isOk;
+    }
+
+    @Override
+    public <T> GResultOf<T> processResults(GResultOf<T> results, String path, boolean isOptional, T defaultVal,
+                                           TypeCapture<T> klass, Tags tags) {
+        if (isOk) {
+            return results;
+        } else {
+            return GResultOf.errors(new ValidationError(ValidationLevel.ERROR) {
+                @Override
+                public String description() {
+                    return "something broke";
+                }
+            });
+        }
+    }
+}