Unit tests

peacemaker · 2025-01-14T07:35:25+0000

HI, All

I know about this term only theoretically.
How should it look in B4X development ? Especially in B4R ...
Any example of codes ?

tchart · 2025-01-14T08:44:19+0000

peacemaker said:
HI, All

I know about this term only theoretically.
How should it look in B4X development ? Especially in B4R ...
Any example of codes ?

Unit tests test exactly that ie a “unit of code”. Generally you would have a separate project that would reference a module from your main project and then test each Sub with an input and then validate that input. You would also have tests that test with a bad input and validate that the error is handled it correctly.

If you look on GitHub at most Java repos under the src directory there will be a main project and then a test project that will call various functions in the main project.

How that translates to B4X I have not yet figured out a good way to do it.

peacemaker · 2025-01-14T08:49:25+0000

tchart said:
not yet figured out a good way

I did not see, and also cannot imagine yet. Do you have an example of such Java repo to check ?
What feature of the programming language and\or IDE must be to allow creation of such tests ?

tchart · 2025-01-14T08:54:16+0000

Ok so have a look at this library

thumbnailator/src at master · coobird/thumbnailator

Thumbnailator - a thumbnail generation library for Java - coobird/thumbnailator

github.com

Notice how there are two folders under src?

These are two Java projects; one is the actual library source code and the other are the tests.

If you look at the test directories you’ll see it will test functions in the main source.

In terms of technology you use the same as you are developing in, so B4J for B4J projects. It’s manual to create the unit tests. I don’t think I’ve seen any scripts to create unit tests automatically but I could be wrong there.

aeric · 2025-01-14T10:54:51+0000

From my understanding, some programming languages use a function call assert to test the functions.
Not sure this practice is useful in RAD tool like B4X or it can be a topic for debate.
Maybe we can test the inputs like division by zero, input Double value where Integer is expected or input String value to an input that expects numeric and input a very long String to test the limit in database field.

peacemaker · 2025-01-14T11:00:30+0000

aeric said:
assert

tchart said:
thumbnailator/src at master · coobird/thumbnailator

Thumbnailator - a thumbnail generation library for Java - coobird/thumbnailator

github.com

Indeed, here always used try\catch and "assertEquals" function:

Java:

        /**
         * Test for
         * {@link Thumbnailator#createThumbnail(File, File, int, int)}
         * where,
         * <p>
         * 1) Input File does not exist.
         * <p>
         * Expected outcome is,
         * <p>
         * 1) Processing will stop with an IOException.
         *
         * @throws IOException
         */
        @Test
        public void testCreateThumbnail_FFII_nonExistentInputFile() throws IOException {
            /*
             * Actual test
             */
            File inputFile = new File("foo.jpg");
            File outputFile = new File("bar.jpg");

            try {
                Thumbnailator.createThumbnail(inputFile, outputFile, 50, 50);
                fail();
            } catch (IOException e) {
                assertEquals("Input file does not exist.", e.getMessage());
            }
        }

aeric said:
topic for debate

Yes, exact for this the topic has been created. To understand the subject...

peacemaker · 2025-01-14T11:06:56+0000

But ... i don't understand yet what this test tests..., when executed...
File names are ... foolish, it's clear that won't be found.

peacemaker · 2025-01-14T11:12:06+0000

B4X:

function assert(condition)
{
  if (!condition) {
    throw "Assertion failed! See stack trace for details";
  }
}

[B4x] Throwables library

This is a simple b4xlib library that just allows throwing an IllegalArgumentException or a NumberFormatException. Sometimes a Toast or Dialog is not enough of an alert that something is going to break if the data passed is incorrect, especially in libraries. Compatible with B4a and B4j...

www.b4x.com

Maybe these can be combined for usage ?
But how to use correctly ?

peacemaker · 2025-01-14T11:35:00+0000

Java:
assertEquals()
The assertEquals() method compares two objects for equality, using their equals() method.

Here is a simple example:

Java:

import org.junit.Test; import static org.junit.Assert.*; public class MyUnitTest { @Test public void testConcatenate() { MyUnit myUnit = new MyUnit(); String result = myUnit.concatenate("one", "two"); assertEquals("onetwo", result); } }

First the myUnit.concatenate() method is called, and the result is stored in the variable result.

Second, the result value is compared to the expected value "onetwo", using the assertEquals() method.

If the two objects are equal according to their implementation of their equals() method, the assertEquals() method will return normally. Otherwise the assertEquals() method will throw an exception, and the test will stop there.

This example compared to String objects, but the assertEquals() method can compare any two objects to each other. The assertEquals() method also come in versions which compare primitive types like int and float to each other.

Seems, clear how to use... What is "@test" ?

aeric · 2025-01-14T12:08:42+0000

I think the @test is an annotation which is special keyword that let the compiler knows to execute as a test.

Daestrum · 2025-01-14T12:33:16+0000

In B4J, the @test annotation in Java is a bit like using #If DEBUG.

In a DEBUG compile, all the code within the #If DEBUG block is compiled and executed.
In a RELEASE build, all the code within the #If DEBUG block is excluded from compilation (though it remains in the source file).

However, the key difference with unit tests is that they provide a detailed report indicating the outcome of each test, specifying whether it passed or failed.

peacemaker · 2025-01-14T12:48:20+0000

aeric said:
...IF practice is useful in RAD tool like B4X

What does it mean ?
When and where are the unit tests useful ? No use in B4X ?

aeric · 2025-01-14T12:56:59+0000

peacemaker said:
What does it mean ?
When and where are the unit tests useful ? No use in B4X ?

I think it is useful if your app has many forms, inputs or calculations such as Web API and accounting.
I am not sure, I don't write such tests except for if I remember correctly I did it during college.

peacemaker · 2025-01-14T13:02:59+0000

I have touched the very sensitive area where the software stability is strictly important.
Read about such test, as important subject for such software, but ... do not understand well how and where these tests help to make software more durable.
And see that B4X is not using them at all...
So, maybe impossible, or non-needed for some reasons...

If to understand the root of the subject - maybe it will help to pass it by and do not use as usual...

Daestrum · 2025-01-14T13:27:20+0000

Super simple example how to emulate @test

B4X:

Sub AppStart (Args() As String)
    Dim a As Int = 3
#if DEBUG    
    ' check against known value
    assertEquals(a,3)
#end if    
    Log("Value = " & a)
End Sub
#if DEBUG
Sub assertEquals(o As Object,testValue As Object)
    If o <> testValue Then
        Log($"Test failed : object ${o} <> ${testValue}"$)
    Else
        Log($"Test passed : object ${o} = ${testValue}"$)
    End If
End Sub
#End If

In DEBUG the test is run - in RELEASE the test is omitted

aeric · 2025-01-14T13:41:10+0000

I think for B4A, there is Firebase Analytics that report errors from the user devices.
It is also easy to debug desktop app.
For my server app I always write or insert access log data and error logs for unexpected error into database table.

In today development which is most on web, it is normal for developer to test the back-end API since it is consumed by front-end (client) on another device.

In Computer Science, we learned about Software Development Life Cycle, where we have SIT, UAT, regression test, stress test and etc.

In enterprise, developer will be blame if the code is not well reviewed and tested. I think it is more on the project management.
There are software testers and QA that check for bugs before going for production. There are time and money to invest for this work.

For small projects, we just quickly fix production bugs where they are found.

Unit test or any test is just to reduce the concern of business people. It cannot 100% guarantee the software is 100% free of bugs.
Just my 2 cents.

aeric · 2025-01-14T13:49:10+0000

peacemaker said:
Especially in B4R ...

I see that B4R project is small and straight forward. I don't know if unit test is suitable for this platform.

peacemaker · 2025-01-14T13:51:51+0000

aeric said:
I see that B4R project is small and simple

You just did not see real projects

But they work...

aeric · 2025-01-14T13:57:26+0000

There are many old discussions on unit test
https://www.google.com/search?q=unit+test+site:www.b4x.com
https://www.b4x.com/android/forum/pages/results/?query=unit+test

aeric · 2025-01-14T14:06:13+0000

aeric said:
unit test is suitable for this platform

Maybe I am wrong.
You can ask ChatGPT or Gemini.

Unit tests

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