Add FileUtil tests

sop-java-picocli/src/main/java/sop/cli/picocli/FileUtil.java

@@ -33,6 +33,26 @@ public class FileUtil {
     public static final String PRFX_ENV = "@ENV:";
     public static final String PRFX_FD = "@FD:";
 
+    private static EnvironmentVariableResolver envResolver = System::getenv;
+
+    public static void setEnvironmentVariableResolver(EnvironmentVariableResolver envResolver) {
+        if (envResolver == null) {
+            throw new NullPointerException("Variable envResolver cannot be null.");
+        }
+        FileUtil.envResolver = envResolver;
+    }
+
+    public interface EnvironmentVariableResolver {
+        /**
+         * Resolve the value of the given environment variable.
+         * Return null if the variable is not present.
+         *
+         * @param name name of the variable
+         * @return variable value or null
+         */
+        String resolveEnvironmentVariable(String name);
+    }
+
     public static File getFile(String fileName) {
         if (fileName == null) {
             throw new NullPointerException("File name cannot be null.");
@@ -45,7 +65,7 @@ public class FileUtil {
             }
 
             String envName = fileName.substring(PRFX_ENV.length());
-            String envValue = System.getenv(envName);
+            String envValue = envResolver.resolveEnvironmentVariable(envName);
             if (envValue == null) {
                 throw new IllegalArgumentException(String.format(ERROR_ENV_FOUND, envName));
             }

sop-java-picocli/src/test/java/sop/cli/picocli/FileUtilTest.java

@@ -0,0 +1,134 @@
+/*
+ * Copyright 2021 Paul Schaub.
+ *
+ * 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 sop.cli.picocli;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import sop.exception.SOPGPException;
+
+public class FileUtilTest {
+
+    @BeforeAll
+    public static void setup() {
+        FileUtil.setEnvironmentVariableResolver(new FileUtil.EnvironmentVariableResolver() {
+            @Override
+            public String resolveEnvironmentVariable(String name) {
+                if (name.equals("test123")) {
+                    return "test321";
+                }
+                return null;
+            }
+        });
+    }
+
+    @Test
+    public void getFile_ThrowsForNull() {
+        assertThrows(NullPointerException.class, () -> FileUtil.getFile(null));
+    }
+
+    @Test
+    public void getFile_prfxEnvAlreadyExists() throws IOException {
+        File tempFile = new File("@ENV:test");
+        tempFile.createNewFile();
+        tempFile.deleteOnExit();
+
+        assertThrows(SOPGPException.AmbiguousInput.class, () -> FileUtil.getFile("@ENV:test"));
+    }
+
+    @Test
+    public void getFile_EnvironmentVariable() {
+        File file = FileUtil.getFile("@ENV:test123");
+        assertEquals("test321", file.getName());
+    }
+
+    @Test
+    public void getFile_nonExistentEnvVariable() {
+        assertThrows(IllegalArgumentException.class, () -> FileUtil.getFile("@ENV:INVALID"));
+    }
+
+    @Test
+    public void getFile_prfxFdAlreadyExists() throws IOException {
+        File tempFile = new File("@FD:1");
+        tempFile.createNewFile();
+        tempFile.deleteOnExit();
+
+        assertThrows(SOPGPException.AmbiguousInput.class, () -> FileUtil.getFile("@FD:1"));
+    }
+
+    @Test
+    public void getFile_prfxFdNotSupported() {
+        assertThrows(IllegalArgumentException.class, () -> FileUtil.getFile("@FD:2"));
+    }
+
+    @Test
+    public void createNewFileOrThrow_throwsForNull() {
+        assertThrows(NullPointerException.class, () -> FileUtil.createNewFileOrThrow(null));
+    }
+
+    @Test
+    public void createNewFileOrThrow_success() throws IOException {
+        File dir = Files.createTempDirectory("test").toFile();
+        dir.deleteOnExit();
+        File file = new File(dir, "file");
+
+        assertFalse(file.exists());
+        FileUtil.createNewFileOrThrow(file);
+        assertTrue(file.exists());
+    }
+
+    @Test
+    public void createNewFileOrThrow_alreadyExists() throws IOException {
+        File dir = Files.createTempDirectory("test").toFile();
+        dir.deleteOnExit();
+        File file = new File(dir, "file");
+
+        FileUtil.createNewFileOrThrow(file);
+        assertTrue(file.exists());
+        assertThrows(SOPGPException.OutputExists.class, () -> FileUtil.createNewFileOrThrow(file));
+    }
+
+    @Test
+    public void getFileInputStream_success() throws IOException {
+        File dir = Files.createTempDirectory("test").toFile();
+        dir.deleteOnExit();
+        File file = new File(dir, "file");
+
+        FileUtil.createNewFileOrThrow(file);
+        FileInputStream inputStream = FileUtil.getFileInputStream(file.getAbsolutePath());
+        assertNotNull(inputStream);
+    }
+
+    @Test
+    public void getFileInputStream_fileNotFound() throws IOException {
+        File dir = Files.createTempDirectory("test").toFile();
+        dir.deleteOnExit();
+        File file = new File(dir, "file");
+
+        assertThrows(SOPGPException.MissingInput.class,
+                () -> FileUtil.getFileInputStream(file.getAbsolutePath()));
+    }
+}