issues/150: Allow projects to customize SkippyRepository's default be…

…havior (#151)

settings.gradle

@@ -3,3 +3,5 @@ include 'skippy-gradle'
 include 'skippy-maven'
 include 'skippy-junit4'
 include 'skippy-junit5'
+include ':skippy-extensions:skippy-repository-filesystem'
+include ':skippy-extensions:skippy-repository-regression-suite'

skippy-core/src/main/java/io/skippy/core/AnalyzedTest.java

@@ -31,7 +31,7 @@
  *      "class": 0,
  *      "result": "PASSED",
  *      "coveredClasses": [0, 1],
- *      "executionId": "C57F877F6F9BF164"
+ *      "executionId": "C57F877F...."
  * }
  * </pre>
  *
@@ -180,16 +180,18 @@ public int compareTo(AnalyzedTest other) {
     }
 
     @Override
-    public boolean equals(Object other) {
-        if (other instanceof AnalyzedTest a) {
-            return Objects.equals(testClassId, a.testClassId);
-        }
-        return false;
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        AnalyzedTest that = (AnalyzedTest) o;
+        return testClassId == that.testClassId &&
+                result == that.result &&
+                Objects.equals(coveredClassesIds, that.coveredClassesIds) &&
+                Objects.equals(executionId, that.executionId);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(testClassId);
+        return Objects.hash(testClassId, result, coveredClassesIds, executionId);
     }
-
 }

skippy-core/src/main/java/io/skippy/core/ClassFile.java

@@ -157,24 +157,26 @@ public String toJson() {
     @Override
     public int compareTo(ClassFile other) {
         return comparing(ClassFile::getClassName)
+                .thenComparing(ClassFile::getPath)
                 .thenComparing(ClassFile::getOutputFolder)
                 .compare(this, other);
     }
 
     @Override
-    public boolean equals(Object other) {
-        if (other instanceof ClassFile c) {
-            return Objects.equals(getClassName() + getOutputFolder(), c.getClassName()  + c.getOutputFolder());
-        }
-        return false;
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ClassFile classFile = (ClassFile) o;
+        return Objects.equals(className, classFile.className) &&
+                Objects.equals(path, classFile.path) &&
+                Objects.equals(outputFolder, classFile.outputFolder);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(getClassName(), getOutputFolder());
+        return Objects.hash(className, path, outputFolder);
     }
 
-
     boolean hasChanged() {
         return ! hash.equals(HashUtil.debugAgnosticHash(outputFolder.resolve(path)));
     }

skippy-core/src/main/java/io/skippy/core/ClassFileContainer.java

@@ -183,4 +183,16 @@ ClassFileContainer merge(ClassFileContainer other) {
         return ClassFileContainer.from(new ArrayList<>(result));
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ClassFileContainer that = (ClassFileContainer) o;
+        return Objects.equals(classFilesById, that.classFilesById);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(classFilesById);
+    }
 }

skippy-core/src/main/java/io/skippy/core/ClassNameAndPrediction.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2023-2024 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 io.skippy.core;
 
 record ClassNameAndPrediction(String className, Prediction prediction) {}

skippy-core/src/main/java/io/skippy/core/DefaultRepositoryExtension.java

@@ -0,0 +1,177 @@
+/*
+ * Copyright 2023-2024 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 io.skippy.core;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.Optional;
+import java.util.zip.Deflater;
+import java.util.zip.Inflater;
+
+import static java.nio.file.Files.*;
+
+/**
+ * Default {@link SkippyRepositoryExtension} implementation that
+ * <ul>
+ *     <li>stores and retrieves all data in / from the .skippy folder,</li>
+ *     <li>only retains the latest {@link TestImpactAnalysis} and </li>
+ *     <li>only retains the JaCoCo execution data files that are referenced by the latest {@link TestImpactAnalysis}.</li>
+ * </ul>
+ * It is intended for small projects that do not care about code coverage reports and thus do not need to store JaCoCo
+ * execution data files. However, it supports projects of any size and the storage of JaCoCo execution data
+ * files. This is useful for experimentation. It is not recommended to be used for large projects and / or
+ * projects that want to store JaCoCo execution data files since it will significantly increase the size of your Git
+ * repository.
+ * <br /><br />
+ * Large projects that want to store and more permanently retain {@link TestImpactAnalysis} instances and JaCoCo
+ * execution data files should provide a custom implementation that stores those arteficts outside the project's
+ * repository in storage systems
+ * like
+ * <ul>
+ *     <li>databases,</li>
+ *     <li>network file systems,</li>
+ *     <li>blob storage like AWS S3,</li>
+ *     <li>etc.</li>
+ * </ul>
+ *
+ * @author Florian McKee
+ */
+public final class DefaultRepositoryExtension implements SkippyRepositoryExtension {
+
+    private final Path projectDir;
+
+    /**
+     * Constructor that will be invoked via reflection.
+     *
+     * @param projectDir the project directory (e.g., ~/repo)
+     */
+    public DefaultRepositoryExtension(Path projectDir) {
+        this.projectDir = projectDir;
+    }
+
+    @Override
+    public Optional<TestImpactAnalysis> findTestImpactAnalysis(String id) {
+        try {
+            var jsonFile = SkippyFolder.get(projectDir).resolve(Path.of("test-impact-analysis.json"));
+
+            if (false == exists(jsonFile)) {
+                return Optional.empty();
+            }
+            var tia = TestImpactAnalysis.parse(readString(jsonFile, StandardCharsets.UTF_8));
+            if ( ! id.equals(tia.getId())) {
+                return Optional.empty();
+            }
+            return Optional.of(tia);
+        } catch (IOException e) {
+            throw new UncheckedIOException("Unable to read test impact analysis: %s.".formatted(e.getMessage()), e);
+        }
+    }
+
+    @Override
+    public void saveTestImpactAnalysis(TestImpactAnalysis testImpactAnalysis) {
+        try {
+            var jsonFile = SkippyFolder.get(projectDir).resolve(Path.of("test-impact-analysis.json"));
+            Files.writeString(jsonFile, testImpactAnalysis.toJson(), StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+            deleteObsoleteExecutionDataFiles(testImpactAnalysis);
+        } catch (IOException e) {
+            throw new UncheckedIOException("Unable to save test impact analysis %s: %s.".formatted(testImpactAnalysis.getId(), e.getMessage()), e);
+        }
+    }
+
+    @Override
+    public void saveJacocoExecutionData(String executionId, byte[] jacocoExecutionData) {
+        try {
+            Files.write(SkippyFolder.get(projectDir).resolve("%s.exec".formatted(executionId)), zip(jacocoExecutionData), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+        } catch (IOException e) {
+            throw new UncheckedIOException("Unable to save JaCoCo execution data %s: %s.".formatted(executionId, e.getMessage()), e);
+        }
+    }
+
+    @Override
+    public Optional<byte[]> findJacocoExecutionData(String testExecutionId) {
+        try {
+            var execFile = SkippyFolder.get(this.projectDir).resolve("%s.exec".formatted(testExecutionId));
+            if (exists(execFile)) {
+                return Optional.of(unzip(readAllBytes(execFile)));
+            }
+            return Optional.empty();
+        } catch (IOException e) {
+            throw new UncheckedIOException("Unable to read JaCoCo execution data %s: %s.".formatted(testExecutionId, e.getMessage()), e);
+        }
+    }
+
+    private void deleteObsoleteExecutionDataFiles(TestImpactAnalysis testImpactAnalysis) {
+        var executions = testImpactAnalysis.getExecutionIds();
+        try (var directoryStream  = Files.newDirectoryStream(SkippyFolder.get(projectDir), path -> path.toString().endsWith(".exec"))) {
+            for (var executionDataFile : directoryStream) {
+                if (false == executions.contains(executionDataFile.getFileName().toString().replaceAll("\\.exec", ""))) {
+                    delete(executionDataFile);
+                }
+            }
+        } catch (IOException e) {
+            throw new UncheckedIOException("Deletion of obsolete execution data files failed: %s".formatted(e.getMessage()), e);
+        }
+    }
+
+    private static byte[] zip(byte[] data) {
+        Deflater deflater = new Deflater();
+        deflater.setInput(data);
+        deflater.finish();
+
+        byte[] buffer = new byte[1024];
+        byte[] result = new byte[0];
+
+        while (!deflater.finished()) {
+            int count = deflater.deflate(buffer);
+            byte[] tmp = new byte[result.length + count];
+            System.arraycopy(result, 0, tmp, 0, result.length);
+            System.arraycopy(buffer, 0, tmp, result.length, count);
+            result = tmp;
+        }
+        deflater.end();
+        return result;
+    }
+
+    private static byte[] unzip(byte[] data) {
+        Inflater inflater = new Inflater();
+        inflater.setInput(data);
+
+        byte[] buffer = new byte[1024];
+        byte[] result = new byte[0];
+
+        try {
+            while (!inflater.finished()) {
+                int count = inflater.inflate(buffer);
+                byte[] tmp = new byte[result.length + count];
+                System.arraycopy(result, 0, tmp, 0, result.length);
+                System.arraycopy(buffer, 0, tmp, result.length, count);
+                result = tmp;
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            inflater.end();
+        }
+
+        return result;
+    }
+
+}

skippy-core/src/main/java/io/skippy/core/PredictionWithReason.java

@@ -16,7 +16,6 @@
 
 package io.skippy.core;
 
-
 /**
  * 2-tuple that contains a {@link Prediction} and the {@link Reason} why the prediction was made.
  *

skippy-core/src/main/java/io/skippy/core/Reason.java

@@ -26,6 +26,12 @@
 record Reason(Category category, Optional<String> details) {
 
     enum Category {
+
+        /**
+         * Skippy was unable to retrieve an existing Test Impact Analysis to make a skip-or-execute decision.
+         */
+        TEST_IMPACT_ANALYSIS_NOT_FOUND,
+
         /**
          * Neither the test nor any of the covered classes have changed.
          */
@@ -59,7 +65,19 @@ enum Category {
         /**
          * The class file of a covered class  was not found on the file system.
          */
-        COVERED_CLASS_CLASS_FILE_NOT_FOUND
+        COVERED_CLASS_CLASS_FILE_NOT_FOUND,
+
+        /**
+         * Coverage for skipped tests is enabled but the test has no execution id. The test needs to be re-run in order
+         * to capture coverage for skipped tests.
+         */
+        MISSING_EXECUTION_ID,
+
+        /**
+         * Coverage for skipped tests is enabled and the test has an execution id. However, Skippy is unable to read the
+         * execution data. The test needs to be re-run in order to capture coverage for skipped tests.
+         */
+        UNABLE_TO_READ_EXECUTION_DATA
     }
 
 }