Build a JUnit 5 Extension for the Snapshotmatcher Library

pom.xml

@@ -5,7 +5,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>io.github.json-snapshot</groupId>
   <artifactId>json-snapshot</artifactId>
-  <version>1.0.17</version>
+  <version>1.0.18</version>
   <packaging>jar</packaging>
 
   <name>json-snapshot</name>
@@ -47,6 +47,7 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+    <junit.version>5.4.1</junit.version>
   </properties>
 
   <dependencies>
@@ -74,12 +75,17 @@
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>
-      <version>5.3.2</version>
+      <version>${junit.version}</version>
     </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>
-      <version>5.3.2</version>
+      <version>${junit.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-params</artifactId>
+      <version>${junit.version}</version>
     </dependency>
     <dependency>
       <groupId>org.mockito</groupId>

src/main/java/io/github/jsonSnapshot/Snapshot.java

@@ -1,6 +1,5 @@
 package io.github.jsonSnapshot;
 
-import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Set;
@@ -15,22 +14,22 @@ public class Snapshot {
 
   private Class clazz;
 
-  private Method method;
+  private String testName;
 
   private Function<Object, String> jsonFunction;
 
   private Object[] current;
 
-  Snapshot(
+  public Snapshot(
       SnapshotFile snapshotFile,
       Class clazz,
-      Method method,
+      String method,
       Function<Object, String> jsonFunction,
       Object... current) {
     this.current = current;
     this.snapshotFile = snapshotFile;
     this.clazz = clazz;
-    this.method = method;
+    this.testName = method;
     this.jsonFunction = jsonFunction;
   }
 
@@ -88,6 +87,6 @@ private String takeSnapshot() {
   }
 
   public String getSnapshotName() {
-    return clazz.getName() + "." + method.getName() + "=";
+    return String.format("%s.%s=", clazz.getName(), testName);
   }
 }

src/main/java/io/github/jsonSnapshot/SnapshotConfig.java

@@ -1,5 +1,10 @@
 package io.github.jsonSnapshot;
 
-public interface SnapshotConfig {
-  String getFilePath();
+import lombok.Builder;
+import lombok.Getter;
+
+@Builder
+@Getter
+public class SnapshotConfig {
+  @Builder.Default private final String filePath = "src/test/java/";
 }

src/main/java/io/github/jsonSnapshot/SnapshotFile.java

@@ -1,6 +1,7 @@
 package io.github.jsonSnapshot;
 
 import java.io.*;
+import java.nio.file.Paths;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.stream.Collectors;
@@ -18,9 +19,9 @@ public class SnapshotFile {
 
   @Getter private Set<String> rawSnapshots;
 
-  SnapshotFile(String filePath, String fileName) throws IOException {
+  public SnapshotFile(String filePath, String fileName) throws IOException {
 
-    this.fileName = filePath + fileName;
+    this.fileName = Paths.get(filePath, fileName).toString();
 
     StringBuilder fileContent = new StringBuilder();
 

src/main/java/io/github/jsonSnapshot/SnapshotMatchException.java

@@ -2,11 +2,11 @@
 
 public class SnapshotMatchException extends RuntimeException {
 
-  SnapshotMatchException(String message) {
+  public SnapshotMatchException(String message) {
     super(message);
   }
 
-  SnapshotMatchException(String message, Throwable cause) {
+  public SnapshotMatchException(String message, Throwable cause) {
     super(message, cause);
   }
 }

src/main/java/io/github/jsonSnapshot/SnapshotMatcher.java

@@ -10,44 +10,32 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.apache.commons.lang3.ArrayUtils;
 import org.apache.commons.lang3.StringUtils;
-import org.assertj.core.util.Arrays;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.jupiter.api.BeforeAll;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.fasterxml.jackson.annotation.JsonAutoDetect;
-import com.fasterxml.jackson.annotation.JsonInclude;
-import com.fasterxml.jackson.core.PrettyPrinter;
-import com.fasterxml.jackson.core.util.DefaultIndenter;
-import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
-import com.fasterxml.jackson.core.util.DefaultPrettyPrinter.Indenter;
-import com.fasterxml.jackson.core.util.Separators;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-
 public class SnapshotMatcher {
 
   private static Logger log = LoggerFactory.getLogger(SnapshotMatcher.class);
-
+  private static final SnapshotConfig DEFAULT_CONFIG = SnapshotConfig.builder().build();
   private static Class clazz = null;
   private static SnapshotFile snapshotFile = null;
   private static List<Snapshot> calledSnapshots = new ArrayList<>();
   private static Function<Object, String> jsonFunction;
 
   public static void start() {
-    start(new DefaultConfig(), defaultJsonFunction());
+    start(DEFAULT_CONFIG, SnapshotUtils.defaultJsonFunction());
   }
 
   public static void start(SnapshotConfig config) {
-    start(config, defaultJsonFunction());
+    start(config, SnapshotUtils.defaultJsonFunction());
   }
 
   public static void start(Function<Object, String> jsonFunction) {
-    start(new DefaultConfig(), jsonFunction);
+    start(DEFAULT_CONFIG, jsonFunction);
   }
 
   public static void start(SnapshotConfig config, Function<Object, String> jsonFunction) {
@@ -94,72 +82,15 @@ public static Snapshot expect(Object firstObject, Object... others) {
       throw new SnapshotMatchException(
           "SnapshotTester not yet started! Start it on @BeforeClass/@BeforeAll with SnapshotMatcher.start()");
     }
-    Object[] objects = mergeObjects(firstObject, others);
+    Object[] objects = SnapshotUtils.mergeObjects(firstObject, others);
     StackTraceElement stackElement = findStackElement();
     Method method = getMethod(clazz, stackElement.getMethodName());
-    Snapshot snapshot = new Snapshot(snapshotFile, clazz, method, jsonFunction, objects);
-    validateExpectCall(snapshot);
+    Snapshot snapshot = new Snapshot(snapshotFile, clazz, method.getName(), jsonFunction, objects);
+    SnapshotUtils.validateExpectCall(snapshot, calledSnapshots);
     calledSnapshots.add(snapshot);
     return snapshot;
   }
 
-  static Function<Object, String> defaultJsonFunction() {
-
-    ObjectMapper objectMapper = buildObjectMapper();
-
-    PrettyPrinter pp = buildDefaultPrettyPrinter();
-
-    return (object) -> {
-      try {
-        return objectMapper.writer(pp).writeValueAsString(object);
-      } catch (Exception e) {
-        throw new SnapshotMatchException(e.getMessage());
-      }
-    };
-  }
-
-  private static PrettyPrinter buildDefaultPrettyPrinter() {
-    DefaultPrettyPrinter pp =
-        new DefaultPrettyPrinter("") {
-          @Override
-          public DefaultPrettyPrinter withSeparators(Separators separators) {
-            this._separators = separators;
-            this._objectFieldValueSeparatorWithSpaces =
-                separators.getObjectFieldValueSeparator() + " ";
-            return this;
-          }
-        };
-    Indenter lfOnlyIndenter = new DefaultIndenter("  ", "\n");
-    pp.indentArraysWith(lfOnlyIndenter);
-    pp.indentObjectsWith(lfOnlyIndenter);
-    return pp;
-  }
-
-  private static ObjectMapper buildObjectMapper() {
-    ObjectMapper objectMapper = new ObjectMapper();
-    objectMapper.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS, true);
-    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
-
-    objectMapper.setVisibility(
-        objectMapper
-            .getSerializationConfig()
-            .getDefaultVisibilityChecker()
-            .withFieldVisibility(JsonAutoDetect.Visibility.ANY)
-            .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
-            .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
-            .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
-    return objectMapper;
-  }
-
-  private static void validateExpectCall(Snapshot snapshot) {
-    for (Snapshot eachSnapshot : calledSnapshots) {
-      if (eachSnapshot.getSnapshotName().equals(snapshot.getSnapshotName())) {
-        throw new SnapshotMatchException(
-            "You can only call 'expect' once per test method. Try using array of arguments on a single 'expect' call");
-      }
-    }
-  }
-
   private static Method getMethod(Class<?> clazz, String methodName) {
     try {
       return Stream.of(clazz.getDeclaredMethods())
@@ -211,15 +142,6 @@ private static boolean hasTestAnnotation(Method method) {
         || method.isAnnotationPresent(BeforeAll.class);
   }
 
-  private static Object[] mergeObjects(Object firstObject, Object[] others) {
-    Object[] objects = new Object[1];
-    objects[0] = firstObject;
-    if (!Arrays.isNullOrEmpty(others)) {
-      objects = ArrayUtils.addAll(objects, others);
-    }
-    return objects;
-  }
-
   private static Class<?> getClass(String className) {
     try {
       return Class.forName(className);

src/main/java/io/github/jsonSnapshot/SnapshotUtils.java

@@ -8,9 +8,21 @@
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.function.Function;
 
+import org.apache.commons.lang3.ArrayUtils;
+import org.assertj.core.util.Arrays;
 import org.mockito.ArgumentCaptor;
 
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.core.PrettyPrinter;
+import com.fasterxml.jackson.core.util.DefaultIndenter;
+import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
+import com.fasterxml.jackson.core.util.Separators;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+
 public class SnapshotUtils {
 
   public static <T> HashMap<String, List<LinkedHashMap<String, Object>>> extractArgs(
@@ -88,4 +100,70 @@ private static <T> HashMap<String, List<LinkedHashMap<String, Object>>> process(
 
     return result;
   }
+
+  public static Function<Object, String> defaultJsonFunction() {
+
+    ObjectMapper objectMapper = buildObjectMapper();
+
+    PrettyPrinter pp = buildDefaultPrettyPrinter();
+
+    return (object) -> {
+      try {
+        return objectMapper.writer(pp).writeValueAsString(object);
+      } catch (Exception e) {
+        throw new SnapshotMatchException(e.getMessage());
+      }
+    };
+  }
+
+  public static PrettyPrinter buildDefaultPrettyPrinter() {
+    DefaultPrettyPrinter pp =
+        new DefaultPrettyPrinter("") {
+          @Override
+          public DefaultPrettyPrinter withSeparators(Separators separators) {
+            this._separators = separators;
+            this._objectFieldValueSeparatorWithSpaces =
+                separators.getObjectFieldValueSeparator() + " ";
+            return this;
+          }
+        };
+    DefaultPrettyPrinter.Indenter lfOnlyIndenter = new DefaultIndenter("  ", "\n");
+    pp.indentArraysWith(lfOnlyIndenter);
+    pp.indentObjectsWith(lfOnlyIndenter);
+    return pp;
+  }
+
+  private static ObjectMapper buildObjectMapper() {
+    ObjectMapper objectMapper = new ObjectMapper();
+    objectMapper.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS, true);
+    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+
+    objectMapper.setVisibility(
+        objectMapper
+            .getSerializationConfig()
+            .getDefaultVisibilityChecker()
+            .withFieldVisibility(JsonAutoDetect.Visibility.ANY)
+            .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
+            .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
+            .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
+    return objectMapper;
+  }
+
+  public static void validateExpectCall(Snapshot snapshot, List<Snapshot> calledSnapshots) {
+    for (Snapshot eachSnapshot : calledSnapshots) {
+      if (eachSnapshot.getSnapshotName().equals(snapshot.getSnapshotName())) {
+        throw new SnapshotMatchException(
+            "You can only call 'expect' once per test method. Try using array of arguments on a single 'expect' call");
+      }
+    }
+  }
+
+  public static Object[] mergeObjects(Object firstObject, Object[] others) {
+    Object[] objects = new Object[1];
+    objects[0] = firstObject;
+    if (!Arrays.isNullOrEmpty(others)) {
+      objects = ArrayUtils.addAll(objects, others);
+    }
+    return objects;
+  }
 }

src/main/java/io/github/jsonSnapshot/junit5/Constants.java

@@ -0,0 +1,17 @@
+package io.github.jsonSnapshot.junit5;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+public class Constants {
+
+  public static final ExtensionContext.Namespace NAMESPACE =
+      ExtensionContext.Namespace.create(SnapshotMatcher.class);
+  public static final String SNAPSHOT_FILE = "snapshotFile";
+  public static final String CALLED_SNAPSHOTS = "calledSnapshots";
+
+  // ***************** JVM Config Values *************************
+  public static final String SNAPSHOT_ROOT_DIR =
+      "junit.jupiter.extensions.snapshotmatcher.snaps.rootDir";
+
+  private Constants() {}
+}