GROOVY-6675 : Base script support for JCommander annotation-based parameters

settings.gradle

@@ -1,5 +1,6 @@
 def subprojects = ['groovy-ant',
         'groovy-bsf',
+        'groovy-cli',
         'groovy-console',
         'groovy-docgenerator',
         'groovy-groovydoc',

src/main/org/codehaus/groovy/transform/BaseScriptASTTransformation.java

@@ -129,22 +129,26 @@ private void changeBaseScriptType(final AnnotatedNode parent, final ClassNode cN
         MethodNode runScriptMethod = ClassHelper.findSAM(baseScriptType);
 
         // If they want to use a name other than than "run", then make the change.
-        if (isSuitableAbstractMethod(runScriptMethod)) {
+        if (isCustomScriptBodyMethod(runScriptMethod)) {
             MethodNode defaultMethod = cNode.getDeclaredMethod("run", Parameter.EMPTY_ARRAY);
-            cNode.removeMethod(defaultMethod);
-            MethodNode methodNode = new MethodNode(runScriptMethod.getName(), runScriptMethod.getModifiers() & ~ACC_ABSTRACT
-                    , runScriptMethod.getReturnType(), runScriptMethod.getParameters(), runScriptMethod.getExceptions()
-                    , defaultMethod.getCode());
-            // The AST node metadata has the flag that indicates that this method is a script body.
-            // It may also be carrying data for other AST transforms.
-            methodNode.copyNodeMetaData(defaultMethod);
-            cNode.addMethod(methodNode);
+            // GROOVY-6706: Sometimes an NPE is thrown here.
+            // The reason is that our transform is getting called more than once sometimes.  
+            if (defaultMethod != null) {
+                cNode.removeMethod(defaultMethod);
+                MethodNode methodNode = new MethodNode(runScriptMethod.getName(), runScriptMethod.getModifiers() & ~ACC_ABSTRACT
+                        , runScriptMethod.getReturnType(), runScriptMethod.getParameters(), runScriptMethod.getExceptions()
+                        , defaultMethod.getCode());
+                // The AST node metadata has the flag that indicates that this method is a script body.
+                // It may also be carrying data for other AST transforms.
+                methodNode.copyNodeMetaData(defaultMethod);
+                cNode.addMethod(methodNode);
+            }
         }
     }
 
-    private boolean isSuitableAbstractMethod(MethodNode node) {
+    private boolean isCustomScriptBodyMethod(MethodNode node) {
         return node != null
-                && !(node.getDeclaringClass().equals(ClassHelper.SCRIPT_TYPE)
+            && !(node.getDeclaringClass().equals(ClassHelper.SCRIPT_TYPE)
                 && "run".equals(node.getName())
                 && node.getParameters().length == 0);
     }

src/test/org/codehaus/groovy/transform/BaseScriptTransformTest.groovy

@@ -106,6 +106,8 @@ class BaseScriptTransformTest extends CompilableTestSupport {
         """
     }
 
+    abstract class MyCustomScript extends Script {}
+
     void testBaseScriptFromCompiler(){
         CompilerConfiguration config = new CompilerConfiguration()
         config.scriptBaseClass = MyCustomScript.name
@@ -259,6 +261,37 @@ class BaseScriptTransformTest extends CompilableTestSupport {
         assert result
     }
 
+    /**
+     * Test GROOVY-6706.  Base script in import (or package) with a SAM.
+     */
+    void testGROOVY_6706() {
+        assertScript '''
+@BaseScript(CustomBase)
+import groovy.transform.BaseScript
+
+assert did_before
+assert !did_after
+
+42
+
+abstract class CustomBase extends Script {
+    boolean did_before = false
+    boolean did_after = false
+
+    def run() {
+        before()
+        def r = internalRun()
+        after()
+        assert r == 42
+    }
+
+    abstract internalRun()
+
+    def before() { did_before = true }
+    def after()  { did_after = true  }
+}'''
+    }
+
     void testBaseScriptOnPackage() {
         def result = new GroovyShell().evaluate('''
             @BaseScript(DeclaredBaseScript)
@@ -315,7 +348,4 @@ class BaseScriptTransformTest extends CompilableTestSupport {
             println 'ok'
         '''
     }
-
 }
-
-abstract class MyCustomScript extends Script {}

subprojects/groovy-cli/build.gradle

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2003-2014 the original author or authors.
+ *
+ * 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.
+ */
+
+dependencies {
+    compile rootProject
+    groovy rootProject
+    testCompile rootProject.sourceSets.test.runtimeClasspath
+    testCompile project(':groovy-cli')
+
+    compile('com.beust:jcommander:1.35')
+}

subprojects/groovy-cli/src/main/java/groovy/cli/JCommanderScript.java

@@ -0,0 +1,263 @@
+/*
+ * Copyright 2014-2014 the original author or authors.
+ *
+ * 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 groovy.cli;
+
+import com.beust.jcommander.JCommander;
+import com.beust.jcommander.ParameterDescription;
+import com.beust.jcommander.ParameterException;
+
+import groovy.lang.MissingPropertyException;
+import groovy.lang.Script;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Field;
+import java.util.List;
+
+import static org.codehaus.groovy.runtime.DefaultGroovyMethods.join;
+
+/**
+ * Base script that provides JCommander declarative (annotation-based) argument processing for scripts.
+ *
+ * @author Jim White
+ */
+
+abstract public class JCommanderScript extends Script {
+    /**
+     * Name of the property that holds the JCommander for this script (i.e. 'scriptJCommander').
+     */
+    public final static String SCRIPT_JCOMMANDER = "scriptJCommander";
+
+    /**
+     * The script body
+     * @return The result of the script evaluation.
+     */
+    protected abstract Object runScriptBody();
+
+    @Override
+    public Object run() {
+        String[] args = getScriptArguments();
+        JCommander jc = getScriptJCommanderWithInit();
+        try {
+            parseScriptArguments(jc, args);
+            for (ParameterDescription pd : jc.getParameters()) {
+                if (pd.isHelp() && pd.isAssigned()) return exitCode(printHelpMessage(jc, args));
+            }
+            runScriptCommand(jc);
+            return exitCode(runScriptBody());
+        } catch (ParameterException pe) {
+            return exitCode(handleParameterException(jc, args, pe));
+        }
+    }
+
+    /**
+     * If the given code is numeric and non-zero, then return that from this process using System.exit.
+     * Non-numeric values (including null) are taken to be zero and returned as-is.
+     *
+     * @param code
+     * @return the given code
+     */
+    public Object exitCode(Object code) {
+        if (code instanceof Number) {
+            int codeValue = ((Number) code).intValue();
+            if (codeValue != 0) System.exit(codeValue);
+        }
+        return code;
+    }
+
+    /**
+     * Return the script arguments as an array of strings.
+     * The default implementation is to get the "args" property.
+     *
+     * @return the script arguments as an array of strings.
+     */
+    public String[] getScriptArguments() {
+        return (String[]) getProperty("args");
+    }
+
+    /**
+     * Return the JCommander for this script.
+     * If there isn't one already, then create it using createScriptJCommander.
+     *
+     * @return the JCommander for this script.
+     */
+    protected JCommander getScriptJCommanderWithInit() {
+        try {
+            JCommander jc = (JCommander) getProperty(SCRIPT_JCOMMANDER);
+            if (jc == null) {
+                jc = createScriptJCommander();
+                // The script has a real property (a field or getter) but if we let Script.setProperty handle
+                // this then it just gets stuffed into a binding that shadows the property.
+                // This is somewhat related to other bugged behavior in Script wrt properties and bindings.
+                // See http://jira.codehaus.org/browse/GROOVY-6582 for example.
+                // The correct behavior for Script.setProperty would be to check whether
+                // the property has a setter before creating a new script binding.
+                this.getMetaClass().setProperty(this, SCRIPT_JCOMMANDER, jc);
+            }
+            return jc;
+        } catch (MissingPropertyException mpe) {
+            JCommander jc = createScriptJCommander();
+            // Since no property or binding already exists, we can use plain old setProperty here.
+            setProperty(SCRIPT_JCOMMANDER, jc);
+            return jc;
+        }
+    }
+
+    /**
+     * Create a new (hopefully just once for this script!) JCommander instance.
+     * The default name for the command name in usage is the script's class simple name.
+     * This is the time to load it up with command objects, which is done by initializeJCommanderCommands.
+     *
+     * @return A JCommander instance with the commands (if any) initialized.
+     */
+    public JCommander createScriptJCommander() {
+        JCommander jc = new JCommander(this);
+        jc.setProgramName(this.getClass().getSimpleName());
+
+        initializeJCommanderCommands(jc);
+
+        return jc;
+    }
+
+    /**
+     * Add command objects to the given JCommander.
+     * The default behavior is to look for Subcommand annotations.
+     *
+     * @param jc The JCommander instance to add the commands (if any) to.
+     */
+    public void initializeJCommanderCommands(JCommander jc) {
+        Class cls = this.getClass();
+        while (cls != null) {
+            Field[] fields = cls.getDeclaredFields();
+            for (Field field : fields) {
+                Annotation annotation = field.getAnnotation(Subcommand.class);
+                if (annotation != null) {
+                    try {
+                        field.setAccessible(true);
+                        jc.addCommand(field.get(this));
+                    } catch (IllegalAccessException e) {
+                        printErrorMessage("Trying to add JCommander @Subcommand but got error '" + e.getMessage()
+                                + "' when getting value of field " + field.getName());
+                    }
+                }
+            }
+
+            cls = cls.getSuperclass();
+        }
+    }
+
+    /**
+     * Do JCommander.parse using the given arguments.
+     * If you want to do any special checking before the Runnable commands get run,
+     * this is the place to do it by overriding.
+     *
+     * @param jc The JCommander instance for this script instance.
+     * @param args  The argument array.
+     */
+    public void parseScriptArguments(JCommander jc, String[] args) {
+        jc.parse(args);
+    }
+
+    /**
+     * If there are any objects implementing Runnable that are part of this command script,
+     * then run them.  If there is a parsed command, then run those objects after the main command objects.
+     * Note that this will not run the main script though, we leave that for run to do (which will happen
+     * normally since groovy.lang.Script doesn't implement java.lang.Runnable).
+     *
+     * @param jc
+     */
+    public void runScriptCommand(JCommander jc) {
+        List<Object> objects = jc.getObjects();
+
+        String parsedCommand = jc.getParsedCommand();
+        if (parsedCommand != null) {
+            JCommander commandCommander = jc.getCommands().get(parsedCommand);
+            objects.addAll(commandCommander.getObjects());
+        }
+
+        for (Object commandObject : objects) {
+            if (commandObject instanceof Runnable) {
+                Runnable runnableCommand = (Runnable) commandObject;
+                if ((Object) runnableCommand != (Object) this) {
+                    runnableCommand.run();
+                }
+            }
+        }
+    }
+
+    /**
+     * Error messages that arise from command line processing call this.
+     * The default is to use the Script's println method (which will go to the
+     * 'out' binding, if any, and System.out otherwise).
+     * If you want to use System.err, a logger, or something, this is the thing to override.
+     *
+     * @param message
+     */
+    public void printErrorMessage(String message) {
+        println(message);
+    }
+
+    /**
+     * If a ParameterException occurs during parseScriptArguments, runScriptCommand, or runScriptBody
+     * then this gets called to report the problem.
+     * The default behavior is to show the exception message using printErrorMessage, then call printHelpMessage.
+     * The return value becomes the return value for the Script.run which will be the exit code
+     * if we've been called from the command line.
+     *
+     * @param jc The JCommander instance
+     * @param args The argument array
+     * @param pe The ParameterException that occurred
+     * @return The value that Script.run should return (2 by default).
+     */
+    public Object handleParameterException(JCommander jc, String[] args, ParameterException pe) {
+        StringBuilder sb = new StringBuilder();
+
+        sb.append("args: [");
+        sb.append(join(args, ", "));
+        sb.append("]");
+        sb.append("\n");
+
+        sb.append(pe.getMessage());
+
+        printErrorMessage(sb.toString());
+
+        printHelpMessage(jc, args);
+
+        return 3;
+    }
+
+    /**
+     * If a @Parameter whose help attribute is annotated as true appears in the arguments.
+     * then the script body is not run and this printHelpMessage method is called instead.
+     * The default behavior is to show the arguments and the JCommander.usage using printErrorMessage.
+     * The return value becomes the return value for the Script.run which will be the exit code
+     * if we've been called from the command line.
+     *
+     * @param jc The JCommander instance
+     * @param args The argument array
+     * @return The value that Script.run should return (1 by default).
+     */
+    public Object printHelpMessage(JCommander jc, String[] args) {
+        StringBuilder sb = new StringBuilder();
+
+        jc.usage(sb);
+
+        printErrorMessage(sb.toString());
+
+        return 2;
+    }
+
+}