Merge pull request #1406 from holajsh/1403_groovy_compilation_fixes

[#1403] 🐛 Fix Groovy compilation unit that tries to write in applicat…

framework/src/play/templates/GroovyTemplate.java

@@ -3,11 +3,13 @@
 import java.io.File;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
@@ -16,9 +18,11 @@
 import org.codehaus.groovy.control.CompilationUnit.IGroovyClassOperation;
 import org.codehaus.groovy.control.CompilerConfiguration;
 import org.codehaus.groovy.control.MultipleCompilationErrorsException;
+import org.codehaus.groovy.control.Phases;
 import org.codehaus.groovy.control.SourceUnit;
 import org.codehaus.groovy.control.messages.ExceptionMessage;
 import org.codehaus.groovy.control.messages.Message;
+import org.codehaus.groovy.control.messages.SimpleMessage;
 import org.codehaus.groovy.control.messages.SyntaxErrorMessage;
 import org.codehaus.groovy.runtime.InvokerHelper;
 import org.codehaus.groovy.syntax.SyntaxException;
@@ -141,34 +145,23 @@ public void compile() {
                 CompilationUnit compilationUnit = new CompilationUnit(compilerConfiguration);
                 compilationUnit.addSource(
                         new SourceUnit(name, compiledSource, compilerConfiguration, tClassLoader, compilationUnit.getErrorCollector()));
-
-				// The following approach to adding the phase operation replaces the original
-				// reflection based approach commented out lower down. This appears to be the
-				// canonical approach and possibly has only been made available in the v3.x
-				// stream but it differs in two ways from the reflection based approach and it's
-				// not clear if and what the impact is:
-				// 1. It does NOT guarantee an empty list of OUTPUT phases operations to begin with.
-				// 2. The new phase operation is added to the start and not the end.
-                // See https://github.com/apache/groovy/blob/GROOVY_3_0_6/src/main/java/org/codehaus/groovy/control/CompilationUnit.java#L349
-                compilationUnit.addPhaseOperation(new IGroovyClassOperation() {
+
+                // Play needs to handle writing the generated Groovy class to the file system but the Groovy
+                // compilation unit by default adds it's own output phase operation to do this that cannot
+                // be replaced using the available public methods. Until Groovy provides this capability
+                // it's necessary to access the compilation unit directly using reflection to replace the
+                // default output operation with the Play Groovy class handler.
+                Field phasesF = compilationUnit.getClass().getDeclaredField("phaseOperations");
+                phasesF.setAccessible(true);
+                Collection[] phases = (Collection[]) phasesF.get(compilationUnit);
+                LinkedList<IGroovyClassOperation> output = new LinkedList<>();
+                phases[Phases.OUTPUT] = output;
+                output.add(new IGroovyClassOperation() {
                     @Override
                     public void call(GroovyClass gclass) {
                         groovyClassesForThisTemplate.add(gclass);
                     }
                 });
-
-                // TOOD: Remove once the above replacement logic has been confirmed.
-//                Field phasesF = compilationUnit.getClass().getDeclaredField("phaseOperations");
-//                phasesF.setAccessible(true);
-//                Collection[] phases = (Collection[]) phasesF.get(compilationUnit);
-//                LinkedList<IGroovyClassOperation> output = new LinkedList<>();
-//                phases[Phases.OUTPUT] = output;
-//                output.add(new IGroovyClassOperation() {
-//                    @Override
-//                    public void call(GroovyClass gclass) {
-//                        groovyClassesForThisTemplate.add(gclass);
-//                    }
-//                });
 
                 compilationUnit.compile();
                 // ouf
@@ -223,12 +216,15 @@ public void call(GroovyClass gclass) {
                             message = message.substring(0, message.lastIndexOf('@'));
                         }
                         throw new TemplateCompilationException(this, line, message);
-                    } else {
-                        ExceptionMessage errorMessage = (ExceptionMessage) e.getErrorCollector().getLastError();
+                    } else if (errorMsg instanceof ExceptionMessage) {
+                        ExceptionMessage errorMessage = ExceptionMessage.class.cast(errorMsg);
                         Exception exception = errorMessage.getCause();
                         Integer line = 0;
                         String message = exception.getMessage();
                         throw new TemplateCompilationException(this, line, message);
+                    } else if (errorMsg instanceof SimpleMessage) {
+                        SimpleMessage errorMessage = SimpleMessage.class.cast(errorMsg);
+                        throw new TemplateCompilationException(this, null, errorMessage.getMessage());
                     }
                 }
                 throw new UnexpectedException(e);