Enable parameter injection for @tempdir and run as initialization int…

…erceptor for fields (#1693)

* Enable parameter injection for @tempdir.
* Prior to this commit @tempdir values were not available to other
  field initializers, now they can be used to initialize other fields.
* Fixed exception when configured baseDir did not exist,
  now @tempdir will create the baseDir directory if it is missing.

docs/extensions.adoc

@@ -533,7 +533,11 @@ def ignoreMyExceptions
 In order to generate a temporary directory for test and delete it after test, annotate a member field of type
 `java.io.File`, `java.nio.file.Path` or untyped using `def` in a spec class (`def` will inject a `Path`).
 Alternatively, you can annotate a field with a custom type that has a public constructor accepting either `java.io.File` or `java.nio.file.Path` as its single parameter (see <<utilities.adoc#file-stystem-fixture, FileSystemFixture>> for an example).
-If the annotated field is `@Shared`, the temporary directory will be shared in the corresponding specification, otherwise every feature method and every iteration per parametrized feature method will have their own temporary directories:
+If the annotated field is `@Shared`, the temporary directory will be shared in the corresponding specification, otherwise every feature method and every iteration per parametrized feature method will have their own temporary directories.
+
+Since Spock 2.4, you can also use parameter injection with `@TempDir`.
+The types follow the same rules as for field injection.
+Valid methods are `setup()`, `setupSpec()`, or any feature methods.
 
 [source,groovy,indent=0]
 ----

docs/release_notes.adoc

@@ -14,6 +14,9 @@ include::include.adoc[]
 
 === Misc
 * Add support for <<extensions.adoc#extension-store,keeping state in extensions>>
+* Add support for parameter injection of `@TempDir`
+* Improve `@TempDir` field injection, now it happens before field initialization, so it can be used by other field initializers.
+* Fix exception when configured `baseDir` was not existing, now `@TempDir` will create the baseDir directory if it is missing.
 * Fix bad error message for collection conditions, when one of the operands is `null`
 
 == 2.4-M1 (2022-11-30)

spock-core/src/main/java/org/spockframework/runtime/extension/builtin/TempDirExtension.java

@@ -10,13 +10,17 @@
 import java.io.File;
 import java.lang.reflect.Constructor;
 import java.nio.file.Path;
+import java.util.EnumSet;
+import java.util.Set;
 
 /**
  * @author dqyuan
  * @since 2.0
  */
 @Beta
 public class TempDirExtension implements IAnnotationDrivenExtension<TempDir> {
+
+  private static final Set<MethodKind> VALID_METHOD_KINDS = EnumSet.of(MethodKind.SETUP, MethodKind.SETUP_SPEC, MethodKind.FEATURE);
   private final TempDirConfiguration configuration;
 
   public TempDirExtension(TempDirConfiguration configuration) {
@@ -25,41 +29,21 @@ public TempDirExtension(TempDirConfiguration configuration) {
 
   @Override
   public void visitFieldAnnotation(TempDir annotation, FieldInfo field) {
-    Class<?> fieldType = field.getType();
-    IThrowableFunction<Path, ?, Exception> mapper = createPathToFieldTypeMapper(fieldType);
-    TempDirInterceptor interceptor = new TempDirInterceptor(mapper, field, configuration.baseDir, configuration.keep);
+    TempDirInterceptor interceptor = TempDirInterceptor.forField(field, configuration.baseDir, configuration.keep);
 
     // attach interceptor
     SpecInfo specInfo = field.getParent();
     if (field.isShared()) {
-      specInfo.getBottomSpec().addInterceptor(interceptor);
+      specInfo.getBottomSpec().addSharedInitializerInterceptor(interceptor);
     } else {
-      for (FeatureInfo featureInfo : specInfo.getBottomSpec().getAllFeatures()) {
-        featureInfo.addIterationInterceptor(interceptor);
-      }
+      specInfo.addInitializerInterceptor(interceptor);
     }
   }
 
-  private IThrowableFunction<Path, ?, Exception> createPathToFieldTypeMapper(Class<?> fieldType) {
-    if (fieldType.isAssignableFrom(Path.class) || Object.class.equals(fieldType)) {
-      return p -> p;
-    }
-    if (fieldType.isAssignableFrom(File.class)) {
-      return Path::toFile;
-    }
-
-    try {
-      return fieldType.getConstructor(Path.class)::newInstance;
-    } catch (NoSuchMethodException ignore) {
-      // fall through
-    }
-    try {
-      Constructor<?> constructor = fieldType.getConstructor(File.class);
-      return path -> constructor.newInstance(path.toFile());
-    } catch (NoSuchMethodException ignore) {
-      // fall through
-    }
-    throw new InvalidSpecException("@TempDir can only be used on File, Path, untyped field, " +
-      "or class that takes Path or File as single constructor argument.");
+  @Override
+  public void visitParameterAnnotation(TempDir annotation, ParameterInfo parameter) {
+    Checks.checkArgument(VALID_METHOD_KINDS.contains(parameter.getParent().getKind()), () -> "@TempDir can only be used on setup, setupSpec or feature method parameters.");
+    TempDirInterceptor interceptor = TempDirInterceptor.forParameter(parameter, configuration.baseDir, configuration.keep);
+    parameter.getParent().addInterceptor(interceptor);
   }
 }

spock-core/src/main/java/org/spockframework/runtime/extension/builtin/TempDirInterceptor.java

@@ -1,36 +1,51 @@
 package org.spockframework.runtime.extension.builtin;
 
-import org.spockframework.runtime.extension.*;
+import org.codehaus.groovy.runtime.ResourceGroovyMethods;
+import org.spockframework.runtime.InvalidSpecException;
+import org.spockframework.runtime.extension.IMethodInterceptor;
+import org.spockframework.runtime.extension.IMethodInvocation;
+import org.spockframework.runtime.extension.IStore;
 import org.spockframework.runtime.model.FieldInfo;
+import org.spockframework.runtime.model.ParameterInfo;
 import org.spockframework.util.*;
 
+import java.io.File;
 import java.io.IOException;
-import java.nio.file.*;
+import java.lang.reflect.Constructor;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.regex.Pattern;
 
-import org.codehaus.groovy.runtime.ResourceGroovyMethods;
-
 import static java.nio.file.FileVisitResult.CONTINUE;
+import static org.spockframework.runtime.model.MethodInfo.MISSING_ARGUMENT;
 
 /**
  * @author dqyuan
  * @since 2.0
  */
 @Beta
 public class TempDirInterceptor implements IMethodInterceptor {
+
+  private static final IStore.Namespace NAMESPACE = IStore.Namespace.create(TempDirInterceptor.class);
   private static final String TEMP_DIR_PREFIX = "spock";
   private static final Pattern VALID_CHARS = Pattern.compile("[^a-zA-Z0-9_.-]++");
 
-  private final IThrowableFunction<Path, ?, Exception> pathToFieldMapper;
-  private final FieldInfo fieldInfo;
+  private final IThrowableBiConsumer<IMethodInvocation, Path, Exception> valueSetter;
+  private final String name;
   private final Path parentDir;
   private final boolean keep;
 
-  TempDirInterceptor(IThrowableFunction<Path, ?, Exception> pathToFieldMapper, FieldInfo fieldInfo,
-                     Path parentDir, boolean keep) {
-    this.pathToFieldMapper = pathToFieldMapper;
-    this.fieldInfo = fieldInfo;
+  private TempDirInterceptor(
+    IThrowableBiConsumer<IMethodInvocation, Path, Exception> valueSetter,
+    String name,
+    Path parentDir,
+    boolean keep) {
+
+    this.valueSetter = valueSetter;
+    this.name = name;
     this.parentDir = parentDir;
     this.keep = keep;
   }
@@ -50,40 +65,58 @@ private String dirPrefix(IMethodInvocation invocation) {
     if (invocation.getIteration() != null) {
       prefix.append('_').append(invocation.getIteration().getIterationIndex());
     }
-    return prefix.append('_').append(fieldInfo.getName()).toString();
+    return prefix.append('_').append(name).toString();
   }
 
   private Path generateTempDir(IMethodInvocation invocation) throws IOException {
     String prefix = dirPrefix(invocation);
     if (parentDir == null) {
       return Files.createTempDirectory(prefix);
     }
+    if (!Files.exists(parentDir)) {
+      Files.createDirectories(parentDir);
+    }
     return Files.createTempDirectory(parentDir, prefix);
   }
 
   protected Path setUp(IMethodInvocation invocation) throws Exception {
     Path tempPath = generateTempDir(invocation);
-    fieldInfo.writeValue(invocation.getInstance(), pathToFieldMapper.apply(tempPath));
+    valueSetter.accept(invocation, tempPath);
     return tempPath;
   }
 
-  protected void destroy(Path path) throws IOException {
-    if (!keep) {
-      deleteTempDir(path);
-    }
-  }
-
   @Override
   public void intercept(IMethodInvocation invocation) throws Throwable {
     Path path = setUp(invocation);
+    invocation.getStore(NAMESPACE).put(path, new TempDirContainer(path, keep));
+    invocation.proceed();
+  }
+
+
+  private static IThrowableFunction<Path, ?, Exception> createPathToTypeMapper(Class<?> targetType) {
+    if (targetType.isAssignableFrom(Path.class) || Object.class.equals(targetType)) {
+      return p -> p;
+    }
+    if (targetType.isAssignableFrom(File.class)) {
+      return Path::toFile;
+    }
+
+    try {
+      return targetType.getConstructor(Path.class)::newInstance;
+    } catch (NoSuchMethodException ignore) {
+      // fall through
+    }
     try {
-      invocation.proceed();
-    } finally {
-      destroy(path);
+      Constructor<?> constructor = targetType.getConstructor(File.class);
+      return path -> constructor.newInstance(path.toFile());
+    } catch (NoSuchMethodException ignore) {
+      // fall through
     }
+    throw new InvalidSpecException("@TempDir can only be used on File, Path, untyped field, " +
+      "or class that takes Path or File as single constructor argument.");
   }
 
-  private void deleteTempDir(Path tempPath) throws IOException {
+  private static void deleteTempDir(Path tempPath) throws IOException {
     if (Files.notExists(tempPath)) {
       return;
     }
@@ -96,7 +129,7 @@ private void deleteTempDir(Path tempPath) throws IOException {
     ResourceGroovyMethods.deleteDir(tempPath.toFile());
   }
 
-  private void tryMakeWritable(Path tempPath) throws IOException {
+  private static void tryMakeWritable(Path tempPath) throws IOException {
     Files.walkFileTree(tempPath, MakeWritableVisitor.INSTANCE);
   }
 
@@ -115,4 +148,45 @@ public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
       return CONTINUE;
     }
   }
+
+  static TempDirInterceptor forField(FieldInfo fieldInfo, Path parentDir, boolean keep) {
+    IThrowableFunction<Path, ?, Exception> typeMapper = createPathToTypeMapper(fieldInfo.getType());
+    return new TempDirInterceptor(
+      (invocation, path) -> fieldInfo.writeValue(invocation.getInstance(), typeMapper.apply(path)),
+      fieldInfo.getName(),
+      parentDir,
+      keep);
+  }
+
+  static TempDirInterceptor forParameter(ParameterInfo parameterInfo, Path parentDir, boolean keep) {
+    IThrowableFunction<Path, ?, Exception> typeMapper = createPathToTypeMapper(parameterInfo.getReflection().getType());
+    return new TempDirInterceptor(
+      (IMethodInvocation invocation, Path path) -> {
+        invocation.resolveArgument(parameterInfo.getIndex(), typeMapper.apply(path));
+      },
+      parameterInfo.getName(),
+      parentDir,
+      keep);
+  }
+
+  static class TempDirContainer implements AutoCloseable {
+    private final Path path;
+    private final boolean keep;
+
+    TempDirContainer(Path path, boolean keep) {
+      this.path = path;
+      this.keep = keep;
+    }
+
+    @Override
+    public void close() {
+      if (!keep) {
+        try {
+          deleteTempDir(path);
+        } catch (IOException e) {
+          ExceptionUtil.sneakyThrow(e);
+        }
+      }
+    }
+  }
 }

spock-core/src/main/java/org/spockframework/util/IThrowableBiConsumer.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024 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
+ *      https://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 org.spockframework.util;
+
+/**
+ * A BiConsumer that may throw a checked exception.
+ *
+ * @author Leonard Brünings
+ * @since 2.4
+ */
+@FunctionalInterface
+public interface IThrowableBiConsumer<A, B, T extends Throwable> {
+  void accept(A a, B b) throws T;
+}

spock-core/src/main/java/org/spockframework/util/IThrowableFunction.java

@@ -21,6 +21,7 @@
  *
  * @author Peter Niederwieser
  */
+@FunctionalInterface
 public interface IThrowableFunction<D, C, T extends Throwable> {
   C apply(D value) throws T;
 }

spock-core/src/main/java/spock/lang/TempDir.java

@@ -36,13 +36,17 @@
  * @TempDir
  * FileSystemFixture fsFixture // will inject an instance of FileSystemFixture with the temp path injected via constructor
  * </code></pre>
+ * <p>
+ * Since Spock 2.4, {@code @TempDir} can be used to annotate a method parameter, with the same behavior as the field types.
+ * Use this if you want to use a temp directory in a single method only.
+ * Valid methods are {@code setup()}, {@code setupSpec()}, or any feature methods.
  *
  * @author dqyuan
  * @since 2.0
  */
 @Beta
 @Retention(RetentionPolicy.RUNTIME)
-@Target(ElementType.FIELD)
+@Target({ElementType.FIELD, ElementType.PARAMETER})
 @ExtensionAnnotation(TempDirExtension.class)
 public @interface TempDir {
 }

spock-specs/src/test/groovy/org/spockframework/docs/extension/TempDirDocSpec.groovy

@@ -29,12 +29,24 @@ class TempDirDocSpec extends Specification {
   @TempDir
   FileSystemFixture path4
 
-  def demo() {
+  // Use for parameter injection of a setupSpec method
+  def setupSpec(@TempDir Path sharedPath) {
+    assert sharedPath instanceof Path
+  }
+
+  // Use for parameter injection of a setup method
+  def setup(@TempDir Path setupPath) {
+    assert setupPath instanceof Path
+  }
+
+  // Use for parameter injection of a feature
+  def demo(@TempDir Path path5) {
     expect:
     path1 instanceof Path
     path2 instanceof File
     path3 instanceof Path
     path4 instanceof FileSystemFixture
+    path5 instanceof Path
   }
 
 // end::example[]