Unit test with files system dependency - hidden files - java

I am writing a "Total Commander" like application in Java. There is quite obvious file system dependency here.
I want to unit test it. I created directory structure for test purposes, I keep it in known location in SVN repository. It works great so far.
Now, I have a method that should ignore hidden files. How can I go about this? Can I mark file hidden in the SVN somehow?
Other solution would be to make one of the files hidden in the build script before running tests, but I'm afraid this would mark file as modified and always show in a commit dialog.
Any suggestions?

I would put all the initialization of a test directory into the tests themselves. And such a case would be simple:
create a directory
put some hidden and visible files into it
test
tear down by removing the directory

Essentially, accessing the file system is a big no-no when unit testing. For starters, these tests are slow(er) than your in-system tests, thus reducing the likelihood of you running your tests at a high frequency (such as with every compilation).
Much better if you use an adapter-pattern to abstract away the access to the file system. I'm a .NET developer so my example will be in C#, but I expect you to be able to translate it simply enough:
public class MyManager
{
private readonly IFileAdapter _fileAdapter;
public MyManager(IFileAdapter fileAdapter)
{
_fileAdapter = fileAdapter;
}
}
public interface IFileAdapter
{
public FileStream Open(string fileName);
public string ReadLine(FileStream fileStream);
// More methods...
}
public class FileAdapter : IFileAdapter
{
public FileStream Open(string fileName)
{
return System.Io.File.Open(fileName);
}
public string ReadLine(FileStream fileStream)
{
return File.Open(fileStream);
}
}
Now, as usual, you can mock the file system, as you would any other class, supplying the returned results. Remember - you are not testing Java's IO classes it is assumed that they work. You are only testing your classes (i.e. MyManager, in the example above).
Leave the tests that actually use the file system to your integration / acceptance tests.
Hope this helps,
Assaf.

I would prefer to abstract file system, so that my unit-test wouldn't require access to real file system. Of course, this abstraction layer must be tested with real file system, but this allow you to reduce dependency on it.
As for storing hidden files in SVN, I second artemb. You should create all files necessary to test in JUnit set up. Presumably, you should prefer setup per test method (#Before and #After). But if you encounter test slowness problems, have a look at #BeforeClass and #AfterClass. I consider they can be used with test suites too.

artemb's answer is correct, you can use #Before and #After to create and remove your structure for each test.
Here is some code I use to create a new directory with some files in it, it will create the directory in the systems temp dir, this is important because depending on the machine your tests will run on, you may will not be allowed to create files or dirs somewhere else. (I had to write this code to allow my tests to be executed on our linux integration machine...)
final String tempdir = System.getProperty("java.io.tmpdir");
final String dirname = Long.toHexString(System.currentTimeMillis());
final File dir = new File(tempdir, dirname);
dir.deleteOnExit();
dir.mkdir();
final String path = dir.getAbsolutePath();
assertTrue(dir.exists());
// pre condition, the directory is empty
assertTrue(dir.list().length == 0);
// create temp files in the directory
final int nbFiles = 3;
for (int i = 0; i < nbFiles; i++) {
(File.createTempFile("test", ".txt", dir)).deleteOnExit();
}
BTW you will have to know on what platform you run to be able to create hiden files...

Related

Getting a specific version of an image with Jib (Maven, Docker, testcontainers)

I'm trying to understand a comment that a colleague made. We're using testcontainers to create a fixture:
import org.testcontainers.containers.GenericContainer;
import org.testcontainers.utility.DockerImageName;
public class SalesforceFixture extends GenericContainer<SalesforceFixture> {
private static final String APPLICATION_NAME = "salesforce-emulator";
public SalesforceFixture() {
// super(ImageResolver.resolve(APPLICATION_NAME));
super(DockerImageName.parse("gcr.io/ad-selfserve/salesforce-emulator:latest"));
...
}
...
The commented code is what it used to be. The next line is my colleague's suggestion. And on that line he commented:
This is the part I don't know. The [ImageResolver] gets the specific version of the emulator, rather than the latest. You need a docker-info file for that though, which jib doesn't automatically generate (but I think it can).
This is what I know or have figured so far:
SalesforceFixture is a class that will be used by other projects to write tests. It spins up a container in Docker, running a service that emulates the real service's API. It's like a local version of the service that behaves enough like the real thing that if one writes code and tests using the fixture, it should work the same in production. (This is where my knowledge ends.)
I looked into ImageResolver—it seems to be a class we wrote that searches a filesystem for something:
public static String resolve(String applicationName, File... roots) {
Stream<File> searchPaths = Arrays.stream(roots).flatMap((value) -> {
return Stream.of(new File(value, "../" + applicationName), new File(value, applicationName));
});
Optional<File> buildFile = searchPaths.flatMap((searchFile) -> {
if (searchFile.exists()) {
File imageFile = new File(searchFile + File.separator + "/target/docker/image-name");
if (imageFile.exists()) {
return Stream.of(imageFile);
}
}
return Stream.empty();
}).findAny();
InputStream build = (InputStream)buildFile.map(ImageResolver::fileStream).orElseGet(() -> {
return searchClasspath(applicationName);
});
if (build != null) {
try {
return IOUtils.toString(build, Charset.defaultCharset()).trim();
} catch (IOException var6) {
throw new RuntimeException("An exception has occurred while reading build file", var6);
}
} else {
throw new RuntimeException("Could not resolve target image for application: " + applicationName);
}
}
But I'm confused. What filesystem? Like, what is the present working directory? My local computer, wherever I ran the Java program from? Or is this from within some container? (I don't think so.) Or maybe the directory structure inside a .jar file? Or somewhere in gcr.io?
What does he mean about a "specific version number" vs. "latest"? I mean, when I build this project, whatever it built is all I have. Isn't that equivalent to "latest"? In what case would an older version of an image be present? (That's what made me think of gcr.io.)
Or, does he mean, that in the project using this project's image, one will not be able to specify a version via Maven/pom.xml—it will always spin up the latest.
Sorry this is long, just trying to "show my work." Any hints welcome. I'll keep looking.
I can't comment on specifics of your own internal implementations, but ImageResolver seems to work on your local filesystem, e.g. it looks into your target/ directory and also touches the classpath. I can imagine this code was just written for resolving an actual image name (not an image), since it also returns a String.
Regarding latest, using a latest tag for a Docker image is generally considered an anti-pattern, so likely your colleague is commenting about this. Here is a random article from the web explaining some of the issues with latest tag:
https://vsupalov.com/docker-latest-tag/
Besides, I don't understand why you ask these questions which are very specific to your project here on SO rather than asking your colleague.

How to access version of my project in build.gradle from a Java class

I'm quite new to Gradle so the answer might be simple, so I apologize if the answer is simple: I have a testing tool that needs to fetch it's version and compare it to the version of the application it is testing. However , the version of my tool is in my build.graddle as
version '1.0'
I tried different way to access it ( such as) :
task generateSources {
File outDir
outDir = file("$buildDir/classes/test/tests/Version.java")
doFirst {
outDir.exists() || outDir.mkdirs()
new File(outDir).write("public class Version { public static final String VERSION = \"$project.version\"; }")
}
}
compileJava.dependsOn generateSources
compileJava.source generateSources.outputs.files, sourceSets.main.java
I found this piece of code to output the version to another java file, but I fail to see how I'd be able to retrieve that info afterwards ( I mean, my tests are defined in src and I would need to point to a file that doesn't exist at compilation -- correct me if I'm wrong here).
Any idea on how I could accomplish this task?
First of all, you are trying to create java source file in your build/classes (it should contain compiled classes, not sources) directory, but you have to do it in your sources, otherwise it won't be compiled. And if you need this new class to be vailable not for tests, then use src/main/java, not src/test/java/
But anyway, I suppose for your case it's much easier to use some properties file for that and replace some token within it during build. That will allow you to make some static logic to get this property value and use it yet before running the build. So all you need is:
1- to have some properties file in your resources src/main/resources (for example app.properties), where should version variable be stored, with it's value like APP_VERSION_TOKEN
version=%APP_VERSION_TOKEN%
2- configure you Gradle processResources to replace tokens, something like this:
processResources {
filesMatching('**/app.properties') {
filter {
it.replace('%APP_VERSION_TOKEN%', version)
}
}
}
3- make some method to read this file and return the value of the property and use it where you need.
And that's all. For unit tests you can have another file with the same name under src/test/resource with the unchanging value you need for testing.

How to get the file name from .properties file in java JUnit?

I have 8 test cases in which each test case makes use of a different file. How do I get the specific file from the .properties file which contains the path for the file(s). Some of the test cases are as shown below:
#Test
public void testIfColDataReadIsCorrect() throws FileNotFoundException{
obj.readExcelToGetData("D:/ExcelTestFiles/testExcelWithAllColData.xlsx");
rowObj= obj.getRowRecord();
assertEquals(rowObj.getName(), TEST_NAME);
assertEquals(rowObj.getId(), TEST_id);
assertEquals(rowObj.getDate(), TEST_DATE);
assertEquals(rowObj.getMessage(), TEST_MSG);
assertEquals(rowObj.getPage(), TEST_PAGE);
assertEquals(rowObj.getType(), TEST_TYPE);
assertEquals(rowObj.getLikeCount(),TEST_LIKECOUNT);
assertEquals(rowObj.getShareCount(), TEST_SHARECOUNT);
assertEquals(rowObj.getCommentCount(), TEST_COMMENTCOUNT);
}
#Test
public void testWhenNameColDoesNotExists() throws FileNotFoundException{
//FacebookDataExtraction obj= new FacebookDataExtraction();
//FacebookFields rowObj=new FacebookFields();
obj.readExcelToGetData("D:/ExcelTestFiles/testExcelWithNoNameCol.xlsx");
rowObj= obj.getRowRecord();
assertEquals(rowObj.getName(), null);
assertEquals(rowObj.getId(), TEST_id);
assertEquals(rowObj.getDate(), TEST_DATE);
assertEquals(rowObj.getMessage(), TEST_MSG);
assertEquals(rowObj.getPage(), TEST_PAGE);
assertEquals(rowObj.getType(), TEST_TYPE);
assertEquals(rowObj.getLikeCount(),TEST_LIKECOUNT);
assertEquals(rowObj.getShareCount(), TEST_SHARECOUNT);
assertEquals(rowObj.getCommentCount(), TEST_COMMENTCOUNT);
}
I think this is not the best practice to directly input the file path to the method readExcelToGetData(). After going through certain posts I found that the files can the put in .properties file and can be read from it. How do I get the specific file path in each test case?
You can load files from the classpath via a ClassLoader. E.g. : this.getClass().getClassLoader().getResourceAsStream("myFiles.properties");
So depending on your IDE, you might put the properties file into your source- or resources folder.
Running the JUnit test with #Parameterized runner allows you to run multiple iterations of the same test with different inputs.
You can read the test parameters from whatever source you wish and use them in the parameterized test without the need to copy the test method for every input.
You'll need at least JUnit 4.11 to use Parameterized.

JUnit Test Cases not changing even though files change

I use Eclipse and Maven and have made a single JUnit test, just to test if it works. The first time I ran the test everything went as expected, but since then, every time I run it, I get the same result, even though I'm changing the actual test-file's content.
I tried just emptying the file, then it said that there are no JUnit test files. But as long as I just have #Test in front of a method in that file, I always get the same results.
Anyone know why that could be?
I tried restarting eclipse.
EDIT:
Just realized that I'm not getting the test results since there is an exception before it gets tested. So, the problem is that I'm always getting the exception even though I changed the file.
Testclass:
public class zipTester {
/**
* The class to be tested on.
*/
private Generator generator;
/**
* Sets up the generator.
*/
#Before
public void setUp() {
generator = new Generator(null, 0);
}
/**
* Creates a zip file and tests whether it exists.
*/
#Test
public void testCreateZip() {
File file = new File("/Users/nicola/Documents/trunk);
generator.createZip(file, new Vector<File>());
}
}
Changed TestClass:
public class zipTester {
#Test
public void heyo() {
}
}
Always getting the following Exception:
java.io.FileNotFoundException: /Users/nicola/Documents/trunk (No such file or directory)
...
1 May be you should clean your project
2 and then recheck project-BuildAutomatically
if still have something wrong,
you can right-click your project "java build path" and open the first tab Source
set default output folder content "test/target/classes"
good luck :)
i think your code was not compiled by eclipse
Seems that happen when there is no file in the relevant location.Because you are passing the file to Generator and try to access that file.Then this exception happen as there are no file to access with generator.
You can follow the below steps to avoid this scenario.
First check is that file exist in that location as below,
File file = new File("/Users/nicola/Documents/trunk");
assertTrue(file.exists());
Then check with your Generator.

Make JAR as a standalone executable

Is there a way to convert JAR lib into JAR standalone?
I need to find a standalone java executable that convert PDF into TIFF and I've found these JARs: http://www.icefaces.org/JForum/posts/list/17504.page
Any ideas?
Easiest might be to create another Jar with a Main() entry point, and then just use the java.exe executable to run it:
e.g.
> java.exe -cp MyJarMain.jar;MyPDFJar.jar com.mydomain.MyMain myPDF.pdf
Where MyMain is a class with a Main static method.
You'll need something with a main entry point to pass in and interpret some command line arguments (myPDF.pdf in my made-up example)
You could do an assembly (are you using maven?) and make sure the Main-Class entry in the manifest.mf points to the main class.
Since there is no main-Method, you have to write one, or write a whole new class to call the class/method TiffConver.convertPDF .
The question is, how you're going to use it. From the command line, you need no executable jar. From the Gui, maybe you want to pass a file to be converted by drag and drop? Then you should take the parameter(s) passed to main as Input-PDF-Names (if they end in .pdf) and pass the names iteratively to TiffConverter, for "a.pdf b.pdf" =>
TiffConver.convertPDF ("a.pdf", "a.tiff");
TiffConver.convertPDF ("b.pdf", "b.tiff");
TiffCoverter will silently overwrite existing tiffs, so check that before or change the code there - this is clearly bad habit, and look out for more such things - I didn't.
/*
* Remove target file if exists
*/
File f = new File(tif);
if (f.exists()) {
f.delete();
}
Maybe you wan't to write a swing-wrapper, which let's you choose Files interactively to be converted. This would be a nice idee, if no filename is given.
If the user passes "a.pdf xy.tiff" you could rename the converted file to xy, as additional feature.
Without a main-class, however, a standalone jar would be magic.
However, building a native executale is almost always a bad idea. You loose portability, you don't profit from security- and performance improvements to the JVM or fixed bugs. For multiple programs you need always an independend bugfix, which you might have to manage yourself, if you don't have a package-management as most linux distros have.
after clearing some questions:
public static void main (String [] args) {
if (args.length == 1 && args[0].endsWith (".pdf")) {
String target = args[0].replaceAll (".pdf$", ".tif");
convertPDF (args[0], target);
}
}
This method you put into TiffConvert. It will allow you to convert a simple pdf-File, and generate a tif-File with the same basename but ending in .tif, silently overwriting an existing one of the same name.
I guess you now need to know how to start it?

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