https://github.com/dernasherbrezon/mockfs

Java FileSystem for simulating IOExceptions
https://github.com/dernasherbrezon/mockfs

filesystem java jdk7 junit mock unit-testing

Last synced: about 13 hours ago
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Java FileSystem for simulating IOExceptions

• Host: GitHub
• URL: https://github.com/dernasherbrezon/mockfs
• Owner: dernasherbrezon
• License: apache-2.0
• Created: 2019-04-14T20:39:12.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2021-06-21T20:04:49.000Z (over 3 years ago)
• Last Synced: 2024-05-02T05:09:19.209Z (7 months ago)
• Topics: filesystem, java, jdk7, junit, mock, unit-testing
• Language: Java
• Size: 44.9 KB
• Stars: 5
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
## About [![Build Status](https://travis-ci.com/dernasherbrezon/mockfs.svg?branch=master)](https://travis-ci.com/dernasherbrezon/mockfs) [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=com.aerse%3Amockfs&metric=alert_status)](https://sonarcloud.io/dashboard?id=com.aerse%3Amockfs)

Java FileSystem for simulating IOExceptions

## Usage

1. Add maven dependency:

```xml

  com.aerse

  mockfs

  1.4

```

2. Ensure code is ready

* Ensure `java.nio.file.Path` is used instead of `java.io.File`. FileSystem is available only for `Path`.

* Ensure `Path::resolve(...)` is used instead of `java.nio.file.Paths.get(...)` or `Path::of(...)`. The latter uses `FileSystems.getDefault()` instead of mocked

* All `Path` should be created from the FileSystem using `FileSystem::getPath(...)` method.

3. Setup the test

For example:

```java

	@Test(expected = IOException.class)

	public void testFailingWrite() throws IOException {

		byte[] data = createSampleData();

		Path path = basePath.resolve(UUID.randomUUID().toString());

		mockFs.mock(path, new FailingByteChannelCallback(5));

		try (OutputStream w = Files.newOutputStream(path)) {

			w.write(data);

		}

	}

```

## Features

 * MockFileSystem could transparently pass the data to the default FileSystem. Just use `com.aerse.mockfs.NoOpByteChannelCallback`:

 ```java

		FileSystem fs = FileSystems.getDefault();

		MockFileSystem mockFs = new MockFileSystem(fs);

		mockFs.mock(path, new NoOpByteChannelCallback());

 ```

 * Use `com.aerse.mockfs.FailingByteChannelCallback` for simulating IOExceptions after configurable number of bytes.

 * Mock read/write to every file in the directory. Just pass this directory to the `com.aerse.mockfs.MockFileSystem::mock(directoryToMock, ...)`