[AB-76] replaced usage templates for commands with a generated usage string, removed possibility to define the usage directly on the help

added Google guava dependency
minor fixes in documentation
fixed versions in main pom

abstracto-application/core/core-impl/src/test/java/dev/sheldan/abstracto/core/command/service/CommandServiceBeanTest.java

@@ -0,0 +1,95 @@
+package dev.sheldan.abstracto.core.command.service;
+
+import dev.sheldan.abstracto.core.command.Command;
+import dev.sheldan.abstracto.core.command.config.CommandConfiguration;
+import dev.sheldan.abstracto.core.command.config.Parameter;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mockito;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.util.Arrays;
+
+import static org.mockito.Mockito.*;
+
+@RunWith(MockitoJUnitRunner.class)
+public class CommandServiceBeanTest {
+
+    private static final String COMMAND_NAME = "test";
+    private static final String PARAMETER_1_NAME = "param1";
+    private static final String PARAMETER_2_NAME = "param2";
+
+    @InjectMocks
+    private CommandServiceBean commandServiceBean;
+
+    @Test
+    public void testUsageWithoutParameters() {
+        executeTest("test", commandWithConfig(getNoParameters()));
+    }
+
+    @Test
+    public void testUsageWithOptionalParameter() {
+        executeTest("test [param1]", commandWithConfig(getOptionalParameterConfig()));
+    }
+
+    @Test
+    public void testUsageWithMandatoryParameter() {
+        executeTest("test <param1>", commandWithConfig(getMandatoryParameterConfig()));
+    }
+
+    @Test
+    public void testUsageWithMixedParameters() {
+        executeTest("test <param1> [param2]", commandWithConfig(getMixedParameterConfig()));
+    }
+
+    private void executeTest(String expectedUsage, Command commandToExecute) {
+        String generatedUsage = commandServiceBean.generateUsage(commandToExecute);
+        Assert.assertEquals(expectedUsage, generatedUsage);
+    }
+
+    private Command commandWithConfig(CommandConfiguration commandConfiguration) {
+        Command command = Mockito.mock(Command.class);
+        when(command.getConfiguration()).thenReturn(commandConfiguration);
+        return command;
+    }
+
+    private CommandConfiguration getNoParameters() {
+        return CommandConfiguration
+                .builder()
+                .name(COMMAND_NAME)
+                .build();
+    }
+
+    private CommandConfiguration getOptionalParameterConfig() {
+        return CommandConfiguration
+                .builder()
+                .name(COMMAND_NAME)
+                .parameters(Arrays.asList(getOptionalParameter(true)))
+                .build();
+    }
+
+    private CommandConfiguration getMandatoryParameterConfig() {
+        return CommandConfiguration
+                .builder()
+                .name(COMMAND_NAME)
+                .parameters(Arrays.asList(getOptionalParameter(false)))
+                .build();
+    }
+
+    private CommandConfiguration getMixedParameterConfig() {
+        Parameter param1 = Parameter.builder().name(PARAMETER_1_NAME).optional(false).build();
+        Parameter param2 = Parameter.builder().name(PARAMETER_2_NAME).optional(true).build();
+        return CommandConfiguration
+                .builder()
+                .name(COMMAND_NAME)
+                .parameters(Arrays.asList(param1, param2))
+                .build();
+    }
+
+    private Parameter getOptionalParameter(boolean b) {
+        return Parameter.builder().name(PARAMETER_1_NAME).optional(b).build();
+    }
+
+}