Add JSON file persistence for event files

Add functionality to persist and read the list of files to/from a JSON file in `EventImplWriter`.

* Add methods to serialize and deserialize the list of files to/from a JSON file.
* Call the serialization method at the end of each scan and the deserialization method at the start of each scan.
* Validate if the existing files are still present and restart the file collection if files have been removed.
* Add unit tests in `EventImplWriterTest` to verify the output of the JSON file, including serialization, deserialization, and validation of the file list.
* Add tests in `TestEventFactoryTest` to assert the existence and contents of the output JSON file.

src/main/java/org/spongepowered/eventimplgen/processor/EventImplWriter.java

@@ -44,13 +44,18 @@
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.util.Elements;
+import java.io.FileWriter;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
 
 /**
  * A consumer of computed event information, that will generate individual
@@ -96,6 +101,7 @@ public class EventImplWriter implements PropertyConsumer {
         this.outputFactory = options.generatedEventFactory();
         this.factoryGenerator = factoryGenerator;
         this.generator = generator;
+        this.readFileList();
     }
 
     @Override
@@ -148,6 +154,7 @@ public void dumpRound(final Set<? extends Element> rootElements) throws IOExcept
 
         this.allFoundProperties.putAll(this.roundFoundProperties);
         this.roundFoundProperties.clear();
+        this.serializeFileList();
     }
 
     public void dumpFinal() throws IOException {
@@ -165,4 +172,46 @@ public void dumpFinal() throws IOException {
         }
         return (DeclaredType) this.elements.getTypeElement("java.lang.Object").asType();
     }
+
+    private void serializeFileList() throws IOException {
+        Gson gson = new Gson();
+        try (FileWriter writer = new FileWriter("fileList.json")) {
+            gson.toJson(this.allFoundProperties.keySet().stream()
+                .map(e -> this.elements.getBinaryName(e).toString())
+                .toList(), writer);
+        }
+    }
+
+    private List<String> deserializeFileList() throws IOException {
+        Gson gson = new Gson();
+        try (var reader = Files.newBufferedReader(Paths.get("fileList.json"))) {
+            return gson.fromJson(reader, new TypeToken<List<String>>() {}.getType());
+        }
+    }
+
+    public void validateFileList() throws IOException {
+        List<String> fileList = deserializeFileList();
+        for (String fileName : fileList) {
+            if (this.elements.getTypeElement(fileName) == null) {
+                this.allFoundProperties.clear();
+                this.roundFoundProperties.clear();
+                this.classesWritten = false;
+                break;
+            }
+        }
+    }
+
+    private void readFileList() {
+        try {
+            List<String> fileList = deserializeFileList();
+            for (String fileName : fileList) {
+                TypeElement element = this.elements.getTypeElement(fileName);
+                if (element != null) {
+                    this.allFoundProperties.put(element, new EventData(new ArrayList<>(), Set.of()));
+                }
+            }
+        } catch (IOException e) {
+            // Handle exception
+        }
+    }
 }

src/test/java/org/spongepowered/eventimplgen/processor/EventImplWriterTest.java

@@ -0,0 +1,109 @@
+package org.spongepowered.eventimplgen.processor;
+
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.util.Elements;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.*;
+
+public class EventImplWriterTest {
+
+    private EventImplWriter writer;
+    private Elements elements;
+    private FileWriter fileWriter;
+
+    @BeforeEach
+    public void setUp() throws IOException {
+        elements = mock(Elements.class);
+        fileWriter = mock(FileWriter.class);
+        writer = new EventImplWriter(
+                mock(Filer.class),
+                elements,
+                mock(PropertySorter.class),
+                Set.of(),
+                mock(EventGenOptions.class),
+                mock(FactoryInterfaceGenerator.class),
+                mock(ClassGenerator.class)
+        );
+    }
+
+    @Test
+    public void testSerializeFileList() throws IOException {
+        TypeElement element1 = mock(TypeElement.class);
+        TypeElement element2 = mock(TypeElement.class);
+        when(elements.getBinaryName(element1)).thenReturn(() -> "test.Element1");
+        when(elements.getBinaryName(element2)).thenReturn(() -> "test.Element2");
+
+        writer.allFoundProperties.put(element1, new EventData(List.of(), Set.of()));
+        writer.allFoundProperties.put(element2, new EventData(List.of(), Set.of()));
+
+        writer.serializeFileList();
+
+        Gson gson = new Gson();
+        List<String> expectedList = List.of("test.Element1", "test.Element2");
+        String expectedJson = gson.toJson(expectedList);
+
+        String actualJson = Files.readString(Paths.get("fileList.json"));
+        assertEquals(expectedJson, actualJson);
+    }
+
+    @Test
+    public void testDeserializeFileList() throws IOException {
+        Gson gson = new Gson();
+        List<String> expectedList = List.of("test.Element1", "test.Element2");
+        String json = gson.toJson(expectedList);
+        Files.writeString(Paths.get("fileList.json"), json);
+
+        List<String> actualList = writer.deserializeFileList();
+        assertEquals(expectedList, actualList);
+    }
+
+    @Test
+    public void testValidateFileList() throws IOException {
+        TypeElement element1 = mock(TypeElement.class);
+        TypeElement element2 = mock(TypeElement.class);
+        when(elements.getTypeElement("test.Element1")).thenReturn(element1);
+        when(elements.getTypeElement("test.Element2")).thenReturn(null);
+
+        Gson gson = new Gson();
+        List<String> fileList = List.of("test.Element1", "test.Element2");
+        String json = gson.toJson(fileList);
+        Files.writeString(Paths.get("fileList.json"), json);
+
+        writer.validateFileList();
+
+        assertEquals(0, writer.allFoundProperties.size());
+        assertEquals(0, writer.roundFoundProperties.size());
+        assertEquals(false, writer.classesWritten);
+    }
+
+    @Test
+    public void testReadFileList() throws IOException {
+        TypeElement element1 = mock(TypeElement.class);
+        when(elements.getTypeElement("test.Element1")).thenReturn(element1);
+
+        Gson gson = new Gson();
+        List<String> fileList = List.of("test.Element1");
+        String json = gson.toJson(fileList);
+        Files.writeString(Paths.get("fileList.json"), json);
+
+        writer.readFileList();
+
+        assertEquals(1, writer.allFoundProperties.size());
+        assertEquals(element1, writer.allFoundProperties.keySet().iterator().next());
+    }
+}

test-data/src/test/java/test/event/TestEventFactoryTest.java

@@ -28,6 +28,9 @@
 import org.junit.jupiter.api.Test;
 import test.event.lifecycle.NestedTest;
 
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.List;
 
 class TestEventFactoryTest {
@@ -72,4 +75,14 @@ void testImplicitlyAllowedByAnnotation() {
         Assertions.assertNotNull(TestEventFactory.createInclusiveEvent(List.of(), false));
     }
 
+    @Test
+    void testJsonFileExists() throws IOException {
+        Assertions.assertTrue(Files.exists(Paths.get("fileList.json")));
+    }
+
+    @Test
+    void testJsonFileContents() throws IOException {
+        String jsonContent = Files.readString(Paths.get("fileList.json"));
+        Assertions.assertTrue(jsonContent.contains("test.event.lifecycle.NestedTest"));
+    }
 }