4.x: Global Service Registry support in tests (#9656)

* Refactoring of global service registry to use Helidon Context to store the value.

* Testing support for Service registry.
This change ensures that all tests are run in a specific "common Context" that holds the current global `ServiceRegistry`.
This way each test class has its own global `ServiceRegistry` instance that does not interfere with other test classes.

all/pom.xml

@@ -443,6 +443,14 @@
             <groupId>io.helidon.common.processor</groupId>
             <artifactId>helidon-common-processor-class-model</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.testing</groupId>
+            <artifactId>helidon-testing</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.helidon.testing</groupId>
+            <artifactId>helidon-testing-junit5</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.helidon.common.testing</groupId>
             <artifactId>helidon-common-testing-junit5</artifactId>

bom/pom.xml

@@ -585,6 +585,16 @@
                 <artifactId>helidon-common-processor-class-model</artifactId>
                 <version>${helidon.version}</version>
             </dependency>
+            <dependency>
+                <groupId>io.helidon.testing</groupId>
+                <artifactId>helidon-testing</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>io.helidon.testing</groupId>
+                <artifactId>helidon-testing-junit5</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
             <dependency>
                 <groupId>io.helidon.common.testing</groupId>
                 <artifactId>helidon-common-testing-junit5</artifactId>

common/common/src/main/java/io/helidon/common/Functions.java

@@ -0,0 +1,266 @@
+/*
+ * Copyright (c) 2025 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.common;
+
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+/**
+ * Functional interfaces required to complement the {@link java.lang.Runnable}, {@link java.util.concurrent.Callable},
+ * and {@link java.util.function.Supplier} to help with checked exceptions in lambdas.
+ */
+public final class Functions {
+    private Functions() {
+    }
+
+    /**
+     * Wrap a {@link CheckedSupplier} into a {@link java.util.function.Supplier}.
+     *
+     * @param supplier checked supplier
+     * @param <T>      supplier type
+     * @param <E>      checked exception type
+     * @return Supplier
+     */
+    public static <T, E extends Throwable> Supplier<T> unchecked(CheckedSupplier<T, E> supplier) {
+        return () -> {
+            try {
+                return supplier.get();
+            } catch (RuntimeException ex) {
+                throw ex;
+            } catch (Throwable ex) {
+                throw new UncheckedException(ex);
+            }
+        };
+    }
+
+    /**
+     * Wrap a {@link CheckedRunnable} into a {@link Runnable}.
+     *
+     * @param runnable checked runnable
+     * @param <E>      checked exception type
+     * @return Consumer
+     */
+    public static <E extends Throwable> Runnable unchecked(CheckedRunnable<E> runnable) {
+        return () -> {
+            try {
+                runnable.run();
+            } catch (RuntimeException | Error ex) {
+                throw ex;
+            } catch (Throwable ex) {
+                throw new UncheckedException(ex);
+            }
+        };
+    }
+
+    /**
+     * Wrap a {@link CheckedConsumer} into a {@link java.util.function.Consumer}.
+     *
+     * @param consumer checked consumer
+     * @param <T>      item type
+     * @param <E>      checked exception type
+     * @return Consumer
+     */
+    public static <T, E extends Throwable> Consumer<T> unchecked(CheckedConsumer<T, E> consumer) {
+        return t -> {
+            try {
+                consumer.accept(t);
+            } catch (RuntimeException | Error ex) {
+                throw ex;
+            } catch (Throwable ex) {
+                throw new UncheckedException(ex);
+            }
+        };
+    }
+
+    /**
+     * Wrap a {@link CheckedBiConsumer} into a {@link java.util.function.BiConsumer}.
+     *
+     * @param consumer checked consumer
+     * @param <T>      1st item type
+     * @param <U>      2nd item type
+     * @param <E>      checked exception type
+     * @return BiConsumer
+     */
+    public static <T, U, E extends Throwable> BiConsumer<T, U> unchecked(CheckedBiConsumer<T, U, E> consumer) {
+        return (t, u) -> {
+            try {
+                consumer.accept(t, u);
+            } catch (RuntimeException | Error ex) {
+                throw ex;
+            } catch (Throwable ex) {
+                throw new UncheckedException(ex);
+            }
+        };
+    }
+
+    /**
+     * Wrap a {@link CheckedBiConsumer} into a {@link BiConsumer}.
+     *
+     * @param function checked function
+     * @param <T>      1st item type
+     * @param <U>      2nd item type
+     * @param <E>      checked exception type
+     * @return Function
+     */
+    public static <T, U, E extends Throwable> Function<T, U> unchecked(CheckedFunction<T, U, E> function) {
+        return t -> {
+            try {
+                return function.apply(t);
+            } catch (RuntimeException | Error ex) {
+                throw ex;
+            } catch (Throwable ex) {
+                throw new UncheckedException(ex);
+            }
+        };
+    }
+
+    /**
+     * Wrap an exception wrapped with {@link UncheckedException} if checked.
+     *
+     * @param ex exception to wrap
+     * @return exception
+     */
+    public static RuntimeException wrap(Throwable ex) {
+        if (ex instanceof RuntimeException runtimeException) {
+            return runtimeException;
+        }
+        return new UncheckedException(ex);
+    }
+
+    /**
+     * Unwrap a checked exception wrapped with {@link UncheckedException}.
+     *
+     * @param ex exception to unwrap
+     * @return exception
+     */
+    public static Throwable unwrap(Throwable ex) {
+        if (ex instanceof UncheckedException) {
+            return ex.getCause();
+        }
+        return ex;
+    }
+
+    /**
+     * Checked consumer.
+     *
+     * @param <T> item type
+     * @param <E> checked exception type
+     */
+    @FunctionalInterface
+    public interface CheckedConsumer<T, E extends Throwable> {
+        /**
+         * Accept an item.
+         *
+         * @param item item
+         * @throws E if an error occurs
+         */
+        void accept(T item) throws E;
+    }
+
+    /**
+     * Checked bi-consumer.
+     *
+     * @param <T> 1st item type
+     * @param <U> 2nd item type
+     * @param <E> checked exception type
+     */
+    @FunctionalInterface
+    public interface CheckedBiConsumer<T, U, E extends Throwable> {
+
+        /**
+         * Accept an item.
+         *
+         * @param item1 1st item
+         * @param item2 2nd item
+         * @throws E if an error occurs
+         */
+        void accept(T item1, U item2) throws E;
+    }
+
+    /**
+     * Checked consumer.
+     *
+     * @param <T> input type
+     * @param <U> output type
+     * @param <E> checked exception type
+     */
+    @FunctionalInterface
+    public interface CheckedFunction<T, U, E extends Throwable> {
+
+        /**
+         * Accept an item.
+         *
+         * @param item input item
+         * @return U
+         * @throws E if an error occurs
+         */
+        U apply(T item) throws E;
+    }
+
+    /**
+     * Checked runnable.
+     *
+     * @param <E> checked exception type
+     */
+    @FunctionalInterface
+    public interface CheckedRunnable<E extends Throwable> {
+
+        /**
+         * Run.
+         *
+         * @throws E if an error occurs
+         */
+        void run() throws E;
+    }
+
+    /**
+     * Checked supplier.
+     *
+     * @param <T> supplier type
+     * @param <E> checked exception type
+     */
+    @FunctionalInterface
+    public interface CheckedSupplier<T, E extends Throwable> {
+
+        /**
+         * Get the value.
+         *
+         * @return T value
+         * @throws E if an error occurs
+         */
+        T get() throws E;
+    }
+
+    /**
+     * Unchecked exception.
+     *
+     * @see #unwrap(Throwable)
+     */
+    public static class UncheckedException extends RuntimeException {
+
+        /**
+         * Create a new unchecked exception.
+         *
+         * @param cause cause
+         */
+        public UncheckedException(Throwable cause) {
+            super(cause);
+        }
+    }
+}