[cli] better format errors in case of a missing required parameter

fusion-api/src/main/java/io/yupiik/fusion/framework/api/configuration/MissingRequiredParameterException.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2022 - present - Yupiik SAS - https://www.yupiik.com
+ * 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.yupiik.fusion.framework.api.configuration;
+
+public class MissingRequiredParameterException extends IllegalArgumentException {
+    public MissingRequiredParameterException(final String msg) {
+        super(msg);
+    }
+}

fusion-cli/src/main/java/io/yupiik/fusion/cli/internal/BaseCliCommand.java

@@ -18,12 +18,16 @@
 import io.yupiik.fusion.framework.api.Instance;
 import io.yupiik.fusion.framework.api.RuntimeContainer;
 import io.yupiik.fusion.framework.api.configuration.Configuration;
+import io.yupiik.fusion.framework.api.configuration.MissingRequiredParameterException;
 import io.yupiik.fusion.framework.api.container.DefaultInstance;
 
 import java.util.List;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
+import static java.util.Comparator.comparing;
+import static java.util.stream.Collectors.joining;
+
 public class BaseCliCommand<CF, C extends Runnable> implements CliCommand<C> {
     private final String name;
     private final String description;
@@ -59,10 +63,26 @@ public List<Parameter> parameters() {
 
     @Override
     public Instance<C> create(final Configuration configuration, final List<Instance<?>> dependents) {
-        return new DefaultInstance<>(
-                null, null,
-                constructor.apply(configurationProvider.apply(configuration), dependents),
-                dependents);
+        final C conf;
+        try {
+            conf = constructor.apply(configurationProvider.apply(configuration), dependents);
+        } catch (final
+        MissingRequiredParameterException missingRequiredParameterException) { // "No value for 'xxx.xxx'"
+            final var rewritten = new MissingRequiredParameterException(
+                    // format as an option and not a config/system prop
+                    missingRequiredParameterException.getMessage().replace(" '", " '--").replace('.', '-') +
+                            formatLightHelp());
+            rewritten.setStackTrace(new StackTraceElement[0]);
+            throw rewritten;
+        }
+        return new DefaultInstance<>(null, null, conf, dependents);
+    }
+
+    private String formatLightHelp() {
+        return parameters.isEmpty() ? "" : ('\n' + parameters.stream()
+                .sorted(comparing(Parameter::cliName))
+                .map(p -> p.cliName() + ": " + p.description())
+                .collect(joining("\n", "Available parameters:\n", "\n")));
     }
 
     public static class ContainerBaseCliCommand<CF, C extends Runnable> extends BaseCliCommand<CF, C> {

fusion-cli/src/test/java/io/yupiik/fusion/cli/internal/BaseCliCommandTest.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2022 - present - Yupiik SAS - https://www.yupiik.com
+ * 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.yupiik.fusion.cli.internal;
+
+import io.yupiik.fusion.framework.api.configuration.MissingRequiredParameterException;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class BaseCliCommandTest {
+    @Test
+    void errorMessage() {
+        assertEquals(
+                """
+                        No value for '--test-dummy'
+                        Available parameters:
+                        --test-dummy: Some param.
+                        """,
+                assertThrows(IllegalArgumentException.class, () -> new BaseCliCommand<Map<String, String>, Runnable>(
+                        "test",
+                        "...",
+                        c -> {
+                            // simulate a parameter required=true which is missing
+                            throw new MissingRequiredParameterException("No value for 'test.dummy'");
+                        },
+                        (conf, deps) -> {
+                            throw new UnsupportedOperationException("shouldn't be called in this test");
+                        },
+                        List.of(new CliCommand.Parameter("test.dummy", "--test-dummy", "Some param.")))
+                        .create(key -> Optional.empty(), List.of()))
+                        .getMessage());
+    }
+}

fusion-processor/src/main/java/io/yupiik/fusion/framework/processor/internal/generator/ConfigurationFactoryGenerator.java

@@ -284,10 +284,8 @@ private String lookup(final String name, final boolean required, final String ma
         return "configuration.get(" + name + ")" +
                 mapper +
                 (required ?
-                        ".orElseThrow(() -> new IllegalArgumentException(\"No value for '" +
-                                name
-                                        .replace("\n", "\\\n")
-                                        .replace("\"", "\\\"") + "'\"))" :
+                        ".orElseThrow(() -> new io.yupiik.fusion.framework.api.configuration.MissingRequiredParameterException(\"No value for '" +
+                                name.substring(1, name.length() - 1) + "'\"))" :
                         ".orElse(" + defaultValue + ")");
     }