Add tests for verifying the contents of the generated gem with the expected content

Author: filiphr

parent/pom.xml

@@ -27,7 +27,7 @@
         <com.puppycrawl.tools.checkstyle.version>8.29</com.puppycrawl.tools.checkstyle.version>
         <add.release.arguments />
         <forkCount>1</forkCount>
-        <assertj.version>3.11.1</assertj.version>
+        <assertj.version>3.17.2</assertj.version>
     </properties>
 
     <licenses>
@@ -286,7 +286,7 @@
                 <configuration>
                     <header>${basedir}/../etc/license.txt</header>
                     <strictCheck>true</strictCheck>
-                    <excludes>
+                    <excludes combine.children="append">
                         <exclude>**/.idea/**</exclude>
                         <exclude>**/.mvn/**</exclude>
                         <exclude>**/etc/checkstyle.xml</exclude>

processor/pom.xml

@@ -61,6 +61,15 @@
 
     <build>
         <plugins>
+            <plugin>
+                <groupId>com.mycila.maven-license-plugin</groupId>
+                <artifactId>maven-license-plugin</artifactId>
+                <configuration>
+                    <excludes>
+                        <exclude>**/src/test/resources/fixtures/**/*.java</exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-jar-plugin</artifactId>

processor/src/test/java/org/mapstruct/tools/gem/processor/ProcessorTest.java

@@ -5,9 +5,15 @@
  */
 package org.mapstruct.tools.gem.processor;
 
+import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
 import java.net.URI;
+import java.nio.file.Path;
 import java.util.Arrays;
+import java.util.Collections;
 import javax.annotation.processing.Processor;
 import javax.tools.Diagnostic;
 import javax.tools.DiagnosticCollector;
@@ -18,6 +24,7 @@
 import javax.tools.StandardLocation;
 import javax.tools.ToolProvider;
 
+import org.assertj.core.api.JUnitSoftAssertions;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -29,6 +36,9 @@ public class ProcessorTest {
     // CHECKSTYLE:OFF
     @Rule
     public final TemporaryFolder tempDir = new TemporaryFolder(); //NOSONAR
+
+    @Rule
+    public final JUnitSoftAssertions softly = new JUnitSoftAssertions();
     // CHECKSTYLE:ON
 
     @Test
@@ -45,7 +55,10 @@ private void compile(Processor processor, JavaFileObject... compilationUnits) th
 
         DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();
         StandardJavaFileManager fileManager = compiler.getStandardFileManager( diagnostics, null, null );
-        fileManager.setLocation( StandardLocation.CLASS_OUTPUT, Arrays.asList( tempDir.getRoot() ) );
+        File classesDir = tempDir.newFolder( "classes" );
+        fileManager.setLocation( StandardLocation.CLASS_OUTPUT, Collections.singletonList( classesDir ) );
+        File generatedDir = tempDir.newFolder( "generated" );
+        fileManager.setLocation( StandardLocation.SOURCE_OUTPUT, Collections.singletonList( generatedDir ) );
 
         JavaCompiler.CompilationTask task = compiler.getTask(
             null,
@@ -65,6 +78,32 @@ private void compile(Processor processor, JavaFileObject... compilationUnits) th
             System.err.println( diagnostic );
         }
         assertThat( success ).isTrue();
+
+
+        assertGeneratedFileContent( "BuilderGem", generatedDir );
+        assertGeneratedFileContent( "SomeAnnotationGem", generatedDir );
+        assertGeneratedFileContent( "SomeAnnotationsGem", generatedDir );
+        assertGeneratedFileContent( "SomeArrayAnnotationGem", generatedDir );
+    }
+
+    protected void assertGeneratedFileContent(String gemName, File generatedDir) {
+        Path gemPath = generatedDir.toPath().resolve( "org/mapstruct/tools/gem/processor/" + gemName + ".java" );
+        softly.assertThat( gemPath )
+            .as( gemName )
+            .exists();
+
+        try (InputStream generatedGemStream = new FileInputStream( gemPath.toFile() );
+             InputStream expectedGemStream = getClass().getClassLoader()
+                 .getResourceAsStream( "fixtures/org/mapstruct/tools/gem/processor/" + gemName + ".java" )
+        ) {
+            softly.assertThat( generatedGemStream )
+                .as( gemName )
+                .hasSameContentAs( expectedGemStream );
+        }
+        catch ( IOException e ) {
+            throw new UncheckedIOException( "Failed to assert generated content for gem " + gemName, e );
+        }
+
     }
 
     private static class StringJavaFileObject extends SimpleJavaFileObject {

processor/src/test/resources/fixtures/org/mapstruct/tools/gem/processor/BuilderGem.java

@@ -0,0 +1,106 @@
+package org.mapstruct.tools.gem.processor;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.AnnotationValue;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.element.VariableElement;
+import javax.lang.model.type.TypeMirror;
+import javax.lang.model.util.AbstractAnnotationValueVisitor8;
+import javax.lang.model.util.ElementFilter;
+import org.mapstruct.tools.gem.Gem;
+import org.mapstruct.tools.gem.GemValue;
+
+
+public class BuilderGem implements Gem {
+
+    private final boolean isValid;
+    private final AnnotationMirror mirror;
+
+    private BuilderGem( BuilderImpl builder ) {
+        isValid = true;
+        mirror = builder.mirror;
+    }
+
+    @Override
+    public AnnotationMirror mirror( ) {
+        return mirror;
+    }
+
+    @Override
+    public boolean isValid( ) {
+        return isValid;
+    }
+
+    public static BuilderGem  instanceOn(Element element) {
+        return build( element, new BuilderImpl() );
+    }
+
+    public static BuilderGem instanceOn(AnnotationMirror mirror ) {
+        return build( mirror, new BuilderImpl() );
+    }
+
+    public static  <T> T  build(Element element, Builder_<T> builder) {
+        AnnotationMirror mirror = element.getAnnotationMirrors().stream()
+            .filter( a ->  "org.mapstruct.tools.gem.test.Builder".contentEquals( ( ( TypeElement )a.getAnnotationType().asElement() ).getQualifiedName() ) )
+            .findAny()
+            .orElse( null );
+        return build( mirror, builder );
+    }
+
+    public static <T> T build(AnnotationMirror mirror, Builder_<T> builder ) {
+
+        // return fast
+        if ( mirror == null || builder == null ) {
+            return null;
+        }
+        builder.setMirror( mirror );
+        return builder.build();
+    }
+
+    /**
+     * A builder that can be implemented by the user to define custom logic e.g. in the
+     * build method, prior to creating the annotation gem.
+     */
+    public interface Builder_<T> {
+
+        /**
+         * Sets the annotation mirror
+         *
+         * @param mirror the mirror which this gem represents
+         *
+         * @return the {@link Builder_} for this gem, representing {@link BuilderGem}
+         */
+          Builder_ setMirror( AnnotationMirror mirror );
+
+        /**
+         * The build method can be overriden in a custom custom implementation, which allows
+         * the user to define his own custom validation on the annotation.
+         *
+         * @return the representation of the annotation
+         */
+        T build();
+    }
+
+    private static class BuilderImpl implements Builder_<BuilderGem> {
+
+        private AnnotationMirror mirror;
+
+        public Builder_  setMirror( AnnotationMirror mirror ) {
+            this.mirror = mirror;
+            return this;
+        }
+
+        public BuilderGem build() {
+            return new BuilderGem( this );
+        }
+    }
+
+}