diff --git a/src/test/java/rife/bld/extension/propertyfile/PropertyFileOperationTest.java b/src/test/java/rife/bld/extension/propertyfile/PropertyFileOperationTest.java
new file mode 100644
index 0000000..22dc242
--- /dev/null
+++ b/src/test/java/rife/bld/extension/propertyfile/PropertyFileOperationTest.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2023-Copyright $today.yearamp;#36;today.year 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 rife.bld.extension.propertyfile;
+
+import org.junit.jupiter.api.Test;
+import rife.bld.Project;
+
+import java.io.File;
+import java.nio.file.Files;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.Properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static rife.bld.extension.propertyfile.Calc.ADD;
+
+class PropertyFileOperationTest {
+    @Test
+    @SuppressWarnings("PMD.AvoidDuplicateLiterals")
+    void testExecute() throws Exception {
+        var tmpFile = File.createTempFile("property-file-", "properties");
+        tmpFile.deleteOnExit();
+
+        new PropertyFileOperation()
+                .fromProject(new Project())
+                .file(tmpFile)
+                .comment("This is a comment")
+                .failOnWarning(true)
+                .entry(new EntryInt("version.major").defaultValue(0).calc(ADD))
+                .entry(new EntryInt("version.minor").set(0))
+                .entry(new EntryInt("version.patch").set(0))
+                .entry(new EntryDate("build.date").now().pattern("yyyy-MM-dd"))
+                .execute();
+
+        var p = new Properties();
+        p.load(Files.newInputStream(tmpFile.toPath()));
+
+        assertThat(p.getProperty("version.major")).as("major").isEqualTo("1");
+        assertThat(p.getProperty("version.minor")).as("minor").isEqualTo("0");
+        assertThat(p.getProperty("version.patch")).as("patch").isEqualTo("0");
+        assertThat(p.getProperty("build.date")).as("date")
+                .isEqualTo(LocalDate.now().format(DateTimeFormatter.ISO_LOCAL_DATE));
+
+        new PropertyFileOperation()
+                .fromProject(new Project())
+                .file(tmpFile.getAbsolutePath())
+                .entry(new EntryInt("version.major").calc(c -> c + 2))
+                .execute();
+
+        p.load(Files.newInputStream(tmpFile.toPath()));
+        assertThat(p.getProperty("version.major")).as("major+2").isEqualTo("3");
+
+        new PropertyFileOperation()
+                .fromProject(new Project())
+                .file(tmpFile)
+                .entry(new EntryInt("build.date").delete())
+                .execute();
+
+        p.clear();
+        p.load(Files.newInputStream(tmpFile.toPath()));
+
+        assertThat(p.getProperty("build.date")).as("dalete build.date").isNull();
+        assertThat(p).as("version keys").containsKeys("version.major", "version.minor", "version.patch");
+    }
+}