There’s a saying that goes, “If a line of code is worth writing, it’s worth testing.” Learn the principles of TDD and see the benefits of it when refactoring old systems, when you have good code coverage. This will mainly be in Javascript with some testing functions we will build in MivaScript.

1. TEST DRIVEN
DEVELOPMENT
TIMOTHY BOLTON

2. Test Driven Development
•What is TDD?
•Why use TDD?
•How to use TDD?
•When to stray from TDD?
•Super Simple Sample of TDD
•Recap

3. What is TDD?
•Development “driven” by testing.
–Tests are written before code is.
–Tests should initially fail
–Production code should be enough to pass
•A simple philosophy
•A great way to make you feel superior

4. Why use TDD?
•It makes refactoring very simple.
•It gives you confidence
•It helps create a scope of work
•It creates a baseline
•It helps you document your project
•It helps bring new developers up to speed

5. How to use TDD?
•There are 3 Rules
1.No production code unless it makes a failing
test pass.
2.No more of a unit test written than is sufficient
to make it fail.
3.No more production code is written than is
sufficient to pass the one failing unit test.

6. How to use TDD cont’d
•Build your own tools
–My Environment consists of:
•Vim
•Tmux
•watchTests.sh Script
•Inotifywait

7. When to stray from TDD?
•Ideally, “never”
•Realistically?
–Working on a pre-existing project
–Working in a language where TDD frameworks
are not established
–When tests take too long. It’s the truth. :’(

8. Super Simple Sample of TDD
•Email address availability with pure
MivaScript and JavaScript
•Remember
–We don’t have a lot of time
–We won’t write a lot of tests for MivaScript
–We don’t have tools built for Mocking
•https://bitbucket.org/snippets/timothybolton/BdL8

9. Super Simple Sample Cont’d
•Where to start?
–MivaScript
•Create a simple “AssertTrue” function
•Create a simple queryEmailTests.mv file
–Put some lipstick on that pig with formatting
–Write the first test
•Create production code

10. Super Simple Sample Cont’d
•What are we trying to accomplish?
See if an email address is used already
•Moving parts and external dependencies
–Database Connection
–Data in Database
–Network Connection

11. Super Simple Sample Cont’d
MivaScript “AssertEqual” function
While we certainly don't need a function to do this, as
we can make simple assertions with “MvIF” statements, it
makes the code easier to read and communicates the
intention.
Other Assertions
AssertTrue, AssertFalse, AssertNull, AssertNotNull
AssertNotEqual, AssertIsDigit, AssertIsAlpha, etc.
Be creative. Work together. Write better scripts.

12. Super Simple Sample Cont’d
FILE NAME: mvassert.mv
1 <MIVA STANDARDOUTPUTLEVEL = "text, compresswhitespace">
2 <MvFUNCTION NAME = "AssertEqual" PARAMETERS = "expected, actual" STANDARDOUTPUTLEVEL="" ERROROUTPUTLEVEL="">
3 <MvFUNCTIONRETURN VALUE = "{ l.expected EQ l.actual }">
4 </MvFUNCTION>

13. Super Simple Sample Cont’d
FILE NAME: mvTestLibrary.mv
1 <MIVA STANDARDOUTPUTLEVEL = "html, compresswhitespace">
2
3 <MvFUNCTION NAME = "generateTestResults" STANDARDOUTPUTLEVEL = "html, compresswhitespace">
4 <MvEVAL EXPR = "{ buildViewStart() }">
5
6 <MvFOR INDEX = "l.pos" FIRST = "{ 1 }" NEXT = "{ ++l.pos }" LAST = "{ g.currentTestNumber }">
7 <MvASSIGN NAME = "l.currentTestStatusStyle" VALUE = "{
generateTestStatusStyle(g.testResults[l.pos]:status) }">
8 <MvEVAL EXPR = "{ generateTestRowData(g.testResults[l.pos]:name, l.currentTestStatusStyle) }">
9 </MvFOR>
10 <MvEVAL EXPR = "{ buildViewEnd() }">
11 </MvFUNCTION>
12
13 <MvFUNCTION NAME = "generateTestRowData" PARAMETERS = "name, style" STANDARDOUTPUTLEVEL =
"compresswhitespace">
14 <MvIF EXPR = "{ g.source EQ 'curlVim' }">
15 <MvASSIGN NAME = "l.view" VALUE = "{ generateTestRowDataCli(l.name, l.style) }">
16 <MvELSE>
17 <MvASSIGN NAME = "l.view" VALUE = "{ generateTestRowDataHtml(l.name, l.style) }">
18 </MvIF>
19 <MvFUNCTIONRETURN VALUE = "{ l.view }">
20 </MvFUNCTION>
21
22 <MvFUNCTION NAME = "generateTestRowDataHtml" PARAMETERS = "name, style" STANDARDOUTPUTLEVEL =
"compresswhitespace">
23 <MvFUNCTIONRETURN VALUE = "{ '<tr><td>' $ l.style $ '</td><td>' $ l.name $ '()</td></tr>' }">
24 </MvFUNCTION>
25
26 <MvFUNCTION NAME = "generateTestRowDataCli" PARAMETERS = "name, style" STANDARDOUTPUTLEVEL =
"compresswhitespace">
27 <MvFUNCTIONRETURN VALUE = "{ '
28 ' $ l.style $ ' ' $ l.name $ '()' }">
29 </MvFUNCTION>
30
31 <MvFUNCTION NAME = "buildViewEnd">
32 <MvIF EXPR = "{ g.source EQ 'curlVim' }">

14. Super Simple Sample Cont’d
FILENAME:queryEmailTests.mv
1 <MIVA STANDARDOUTPUTLEVEL = "text">
2 <MvINCLUDE FILE = "mvassert.mv">
3 <MvINCLUDE FILE = "mvTestLibrary.mv">
4 <MvINCLUDE FILE = "queryEmailFunctions.mv">
5 <MvASSIGN NAME = "g.currentTestNumber" VALUE = 0>
7 <MvCOMMENT>Tests are run here</MvCOMMENT>
8 <MvASSIGN NAME = "l.result" VALUE = "{ testEmailAvailableOnAddress() }">
10 <MvEVAL EXPR = "{ generateTestResults() }">
11 <MvEXIT>
13 <MvCOMMENT>Tests are written here</MvCOMMENT>
14 <MvFUNCTION NAME = "testEmailAvailableOnAddress" STANDARDOUTPUTLEVEL = "compresswhitespace">
15 <MvASSIGN NAME = "g.currentTestNumber" VALUE = "{ ++g.currentTestNumber }">
16 <MvASSIGN NAME = "g.testResults" MEMBER = "status" INDEX = "{ g.currentTestNumber }" VALUE = "{
AssertEqual(1, CheckEmailAvailable('jimmy@jon.net')) }">
17 <MvASSIGN NAME = "g.testResults" MEMBER = "name" INDEX = "{ g.currentTestNumber }" VALUE = "{
'testEmailAvailableOnAddress' }">
18 </MvFUNCTION>

15. Super Simple Sample Cont’d
Vim integration (put in your .vimrc, and
validate for your sites)
nnoremap <Leader>ca :! mvc % && curl -T %c ftp://ftp.mivamerchantdev.com/mm5/5.00/modules/util/ -u
bolton.timothy@gmail.com@dts2639.mivamerchantdev.com:$MIVAPASSWORD && clear && curl
http://dts2639.mivamerchantdev.com/mm5/5.00/modules/util/%c?Store_Code=MIVA_DEV&source=curlVim<CR>

16. Super Simple Sample Cont’d
We have our first test, let's try to run it.
What do you think will happen?
That's right… it won't work.
We need to write our production function.

17. Super Simple Sample Cont’d
Boiler Plate Code
FILENAME: queryEmailFunctions.mv
1 <MIVA STANDARDOUTPUTLEVEL = "text, compresswhitespace">
2 <MvCOMMENT> 99% of this code is from the LSK or the fora.</MvCOMMENT>
3 <MvDO FILE = "../../lib/config.mvc">
4
5 <MvIF EXPR = "{ NOT [ '../../lib/db.mvc' ].OpenDataFiles( g.Merchant_Version, g.Domain ) }">
6 <MvEXIT>
7 </MvIF>
8
9 <MvEVAL EXPR = "{ [ '../../lib/util.mvc' ].SetRuntimePaths() }">
10
11 <MvIF EXPR = "{ NOT [ g.Module_Library_DB ].Store_Open( g.Store_Code, g.Store ) }">
12 <MvIF EXPR = "{ NOT g.Store_Code }"> <MvEVAL EXPR = "{ 'YOU NEED TO SUPPLY g.Store_Code' }"> </MvIF>
13 <MvEXIT>
14 </MvIF>

18. Super Simple Sample Cont’d
16 <MvFUNCTION NAME = "CheckEmailAvailable" PARAMETERS = "email" STANDARDOUTPUTLEVEL = "" ERROROUTPUTLEVEL =
"">
17 <MvOPENVIEW NAME = "Merchant"
18 VIEW = "Customers"
19 QUERY = "{ 'SELECT COUNT(*) AS emailUsed '
20 $ 'FROM ' $ g.Store_Table_Prefix $ 'Customers '
21 $ 'WHERE ' $ [ g.Module_Library_Native_DBAPI ].DB_Compare_UPPER( 'pw_email' )
22 $ ' = '
23 $ [ g.Module_Library_Native_DBAPI ].DB_Compare_UPPER( '?' ) }"
24 FIELDS = "l.email">
25 <MvIF EXPR = "{ Customers.d.emailUsed GT 0 }">
26 <MvASSIGN NAME = "l.returnValue" VALUE = "0">
27 <MvELSE>
28 <MvASSIGN NAME = "l.returnValue" VALUE = "1">
29 </MvIF>
30 <MvCLOSEVIEW NAME = "Merchant" VIEW = "Customers" >
31 <MvFUNCTIONRETURN VALUE = "{l.returnValue }">
32 </MvFUNCTION>

19. Super Simple Sample Cont’d
What happens when we run now?
Using our Vim plugin, we can run from within
our editor, from the CLI, or via the web. The
mvTestFramework has detection from passed
in parameters, to see the output we specify.

20. Super Simple Sample Cont’d
Separation
Separation function declarations from side-effects
This make testing easier
Our compiled script
1 <MIVA STANDARDOUTPUTLEVEL = "text, compresswhitespace">
2 <MvINCLUDE FILE="queryEmailFunctions.mv">
4 <MvEVAL EXPR = "{ CheckEmailAvailable(g.username) }">
5 <MvEXIT>

21. Super Simple Sample Cont’d
Test again.
Now we can rinse and repeat with another
test.

22. Super Simple Sample Cont’d
JavaScript Testing
Ajax can be difficult without mocking, or
using synchronous calls. Which would then be
“Jax”… because, there is no 'A'.
This is depreciated because it degrades the
user experience, but it can be useful for
testing.

23. Super Simple Sample Cont’d
Our simple assertion library will leverage
some of the console behavior that comes with
Chrome and other browsers.
We will just create a simple tdd page that we
can protect.

24. Super Simple Sample Cont’d
1 var testAjax = new XMLHttpRequest();
2
3 testAjax.onreadystatechange = function() {
4 if(testAjax.readyState == 4 && testAjax.status == 200) {
5 return parseInt(testAjax.responseText);
6 }
7 }
8
9 function testAvailableEmail(email) {
10 testAjax.open("GET", "5.00/modules/util/queryEmail.mvc?store_code=MIVA_DEV&username=" + email, false);
11 testAjax.send();
12 return { "test": arguments.callee.name,
13 "actual": testAjax.responseText,
14 "expected": 1
15 };
16 }
17
18 function testUnavailableEmail(email) {
19 testAjax.open("GET", "5.00/modules/util/queryEmail.mvc?store_code=MIVA_DEV&username=" + email, false);
20 testAjax.send();
21 return { "test": arguments.callee.name,
22 "actual": testAjax.responseText,
23 "expected": 0
24 };
25 }
26
27 var testInformation = new Array();
28
29 testInformation.push(testAvailableEmail('notused@example.com'));
30 testInformation.push(testUnavailableEmail('bolton.timothy@gmail.com'));
31
32 for(var i = 0; i < testInformation.length; i++) {
33 console.assert(testInformation[i].actual == testInformation[i].expected, testInformation[i].test + '
Failed. '
34 + 'Actual: ' + testInformation[i].actual + '. Expected: ' + testInformation[i].expected );
35 }

25. Super Simple Sample Cont’d
17 function testUnavailableEmail(email) {
18 testAjax.open("GET", "5.00/modules/util/queryEmail.mvc?store_code=MIVA_DEV&username=" + email, false);
19 testAjax.send();
20 return { "test": arguments.callee.name,
21 "actual": testAjax.responseText,
22 "expected": 0 };
23 }

26. Super Simple Sample Cont’d
27 testInformation.push(testAvailableEmail('notused@example.com'));
28 testInformation.push(testUnavailableEmail('bolton.timothy@gmail.com'));
29
30 for(var i = 0; i < testInformation.length; i++) {
31 console.assert(testInformation[i].actual == testInformation[i].expected,
32 testInformation[i].test + ' Failed. '
33 + 'Actual: ' + testInformation[i].actual + '. Expected: ' + testInformation[i].expected );
34 }

27. Super Simple Sample Cont’d
We are ready to put up some production
code now.

28. Super Simple Sample Cont’d
1 var newAjax = new XMLHttpRequest();
2
3 newAjax.onreadystatechange = function() {
4 if(newAjax.readyState == 4 && newAjax.status == 200) {
5 responseAction(newAjax.responseText);
6 }
7 }
8
9 var email = document.getElementById('Customer_LoginEmail');
10
11 email.onchange = function() {
12 newAjax.open("GET", "5.00/modules/util/queryEmail.mvc?store_code=MIVA_DEV&username=" + this.value);
13 newAjax.send();
14 }
15
16 function responseAction(response) {
17 var alertText = "";
18 if(parseInt(response) == 0) {
19 alertText = "That username is unavailable";
20 } else {
21 alertText = "that username is available";
22 }
23 alert(alertText);
24 }

29. Super Simple Sample Cont’d
We are ready to put up some production
code now.
We have successfully test driven developed.

30. Exercises
Refactor this to use JSON
Add more tests
Add more functionality

31. Parting Thoughts
See the value in your tests now that they are
reusable.
It is annoying at first, but it pays off. Tests like
this have small upkeep, and give you a lot of
freedom to experiment.
I hated TDD at first. Now, I think it's “okay”

32. Thank you!

33. TIMOTHY BOLTON