Test helper for refaster checks

.gitignore

@@ -12,7 +12,7 @@
 .project
 .settings
 build
-/out/
+out/
 gradle.properties
 docs/node_modules/
 generated_src

baseline-refaster-rules/build.gradle

@@ -5,4 +5,7 @@ apply from: "${rootDir}/gradle/publish-jar.gradle"
 
 dependencies {
     compile 'com.google.errorprone:error_prone_refaster'
+
+    testCompile 'junit:junit'
+    testCompile project(':baseline-refaster-testing')
 }

baseline-refaster-rules/src/test/java/com/palantir/baseline/refaster/CollectionsIsEmptyTest.java

@@ -0,0 +1,40 @@
+/*
+ * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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 com.palantir.baseline.refaster;
+
+import org.junit.Test;
+
+public class CollectionsIsEmptyTest {
+
+    @Test
+    public void test() {
+        RefasterTestHelper
+                .forRefactoring(CollectionsIsEmpty.class)
+                .withInputLines(
+                        "Test",
+                        "import java.util.ArrayList;",
+                        "public class Test {",
+                        "  boolean empty = new ArrayList<>().size() == 0;",
+                        "}")
+                .hasOutputLines(
+                        "import java.util.ArrayList;",
+                        "public class Test {",
+                        "  boolean empty = new ArrayList<>().isEmpty();",
+                        "}");
+    }
+
+}

baseline-refaster-rules/src/test/java/com/palantir/baseline/refaster/OptionalOrElseSupplierTest.java

@@ -0,0 +1,44 @@
+/*
+ * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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 com.palantir.baseline.refaster;
+
+import org.junit.Test;
+
+public class OptionalOrElseSupplierTest {
+
+    @Test
+    public void test() {
+        RefasterTestHelper
+                .forRefactoring(OptionalOrElseSupplier.class)
+                .withInputLines(
+                        "Test",
+                        "import java.util.*;",
+                        "import java.util.function.Supplier;",
+                        "public class Test {",
+                        "  Supplier<String> supplier = () -> \"hello\";",
+                        "  String s = Optional.ofNullable(\"world\").orElse(supplier.get());",
+                        "}")
+                .hasOutputLines(
+                        "import java.util.*;",
+                        "import java.util.function.Supplier;",
+                        "public class Test {",
+                        "  Supplier<String> supplier = () -> \"hello\";",
+                        "  String s = Optional.ofNullable(\"world\").orElseGet(supplier);",
+                        "}");
+    }
+
+}

baseline-refaster-rules/src/test/java/com/palantir/baseline/refaster/SortedFirstTest.java

@@ -0,0 +1,45 @@
+/*
+ * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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 com.palantir.baseline.refaster;
+
+import org.junit.Test;
+
+public class SortedFirstTest {
+
+    @Test
+    public void test() {
+        RefasterTestHelper
+                .forRefactoring(SortedFirst.class)
+                .withInputLines(
+                        "Test",
+                        "import java.util.*;",
+                        "import java.util.stream.Stream;",
+                        "public class Test {",
+                        "  Optional<Integer> i = Arrays.asList(5, -10, 7, -18, 23).stream()",
+                        "      .sorted(Comparator.reverseOrder())",
+                        "      .findFirst();",
+                        "}")
+                .hasOutputLines(
+                        "import java.util.*;",
+                        "import java.util.stream.Stream;",
+                        "public class Test {",
+                        "  Optional<Integer> i = Arrays.asList(5, -10, 7, -18, 23).stream()"
+                                + ".min(Comparator.reverseOrder());",
+                        "}");
+    }
+
+}

baseline-refaster-rules/src/test/java/com/palantir/baseline/refaster/Utf8LengthTest.java

@@ -0,0 +1,41 @@
+/*
+ * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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 com.palantir.baseline.refaster;
+
+import org.junit.Test;
+
+public class Utf8LengthTest {
+
+    @Test
+    public void test() {
+        RefasterTestHelper
+                .forRefactoring(Utf8Length.class)
+                .withInputLines(
+                        "Test",
+                         "import java.nio.charset.StandardCharsets;",
+                        "public class Test {",
+                        "  int i = \"hello world\".getBytes(StandardCharsets.UTF_8).length;",
+                        "}")
+                .hasOutputLines(
+                        "import com.google.common.base.Utf8;",
+                        "import java.nio.charset.StandardCharsets;",
+                        "public class Test {",
+                        "  int i = Utf8.encodedLength(\"hello world\");",
+                        "}");
+    }
+
+}

baseline-refaster-testing/build.gradle

@@ -0,0 +1,27 @@
+/*
+ * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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.
+ */
+
+apply plugin: 'java-library'
+apply from: "${rootDir}/gradle/publish-jar.gradle"
+
+dependencies {
+    compile 'com.google.errorprone:error_prone_refaster'
+    compile 'com.google.errorprone:error_prone_test_helpers'
+
+    compile 'com.google.guava:guava'
+    compile 'junit:junit'
+    compile 'org.assertj:assertj-core'
+}

baseline-refaster-testing/src/main/java/com/palantir/baseline/refaster/CompilerUtility.java

@@ -0,0 +1,88 @@
+/*
+ * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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 com.palantir.baseline.refaster;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.CharStreams;
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.tools.javac.api.JavacTaskImpl;
+import com.sun.tools.javac.api.JavacTool;
+import com.sun.tools.javac.util.Context;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Locale;
+import javax.tools.Diagnostic;
+import javax.tools.DiagnosticCollector;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
+import javax.tools.StandardJavaFileManager;
+
+final class CompilerUtility {
+
+    private CompilerUtility() {}
+
+    static CompilerResult compile(JavaFileObject javaFileObject) {
+        JavaCompiler compiler = JavacTool.create();
+        DiagnosticCollector<JavaFileObject> diagnosticsCollector = new DiagnosticCollector<>();
+        StandardJavaFileManager fileManager =
+                compiler.getStandardFileManager(diagnosticsCollector, Locale.ENGLISH, StandardCharsets.UTF_8);
+
+        JavacTaskImpl task = (JavacTaskImpl) compiler.getTask(
+                CharStreams.nullWriter(),
+                fileManager,
+                diagnosticsCollector,
+                ImmutableList.of(),
+                null,
+                ImmutableList.of(javaFileObject));
+
+        Iterable<? extends CompilationUnitTree> trees;
+        try {
+            trees = task.parse();
+            task.analyze();
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+
+        return new CompilerResult() {
+            @Override
+            public Context context() {
+                return task.getContext();
+            }
+
+            @Override
+            public List<CompilationUnitTree> compilationUnits() {
+                return ImmutableList.copyOf(trees);
+            }
+
+            @Override
+            public List<Diagnostic<? extends JavaFileObject>> diagnostics() {
+                return diagnosticsCollector.getDiagnostics();
+            }
+        };
+    }
+
+    interface CompilerResult {
+
+        Context context();
+
+        List<CompilationUnitTree> compilationUnits();
+
+        List<Diagnostic<? extends JavaFileObject>> diagnostics();
+
+    }
+
+}