Unit test tips

Automated unit tests provide a safety net to enhance application so that we wont be afraid to make a change without introducing defects and it also makes an application more maintainable.

Unit test names must be robust; They should be named after the functionality that they are testing. A recommended way to name unit tests is to use the Noun+should+verb pattern.

A body of a test method should be arranged using the AAA pattern (arrange, act, assert).

-          Arrange: This section contains code that sets up the variables that will be used by the unit test.

-          Act : This section execercises the unit under testing and capture the results.

-          Assert: This section verifies the results of the unit test against expectations.

Avoid tests that do too much. Verify only a single concept to make it easier to pinpoint the cause of failures.

A good point is to have only a single assert statement in a test method. If you have multiple asserts, make sure that they are verifying the same concept.

Unit testing with a real database brings a number of challenges:

1.       It significantly slows down the execution time of unit tests.The longer it takes to run the tests, the less likely you will run them frequently. Ideally you would want unit tests to run in seconds- something you do naturally as compiling the project.

2.       It complicates the setup and cleanup logic within the tests. You want each unit test to be isolated and independent of the others with no side effects or dependencies. When working against a real database, you have to be also mindful of state and reset the values between the tests.

To overcome this challenge, it is recommended to use the dependency injection design pattern.

Dependency Injection

Dependencies, like repository classes are no longer implicitly created within the classes that use them. This will allow us to test specific scenarios without requiring a connection to the database.

Cobra Log Analyzer

The Cobra Log Analyzer is a tool I’ve developed that assists in analyzing xml log files from Cobra.

It can consolidate multiple Cobra xml log files into a single window where it can be viewed, filtered and analyzed.

Opening Log Files

This is the main window for Cobra Log Analyzer.

Click on the open button to open a cobra log file.
Select one or more log files to process and click on Open.

Files can also be drag and dropped from explorer into the main window.

This works similar to opening a file via the open dialog.

The Cobra Log Analyzer is optimized to open massive log files.
Multiple threads are spawned to quickly process multiple files asycnhronously.

Grouping and Filtering

The information presented in the main grid can be grouped by simply dragging the desired column into the header band.

The visible cells can also be filtered via the filter icon for every column.

Search

Click on the search icon to bring up the search dialog.

The value specified shall be used to search the content column in the grid.

Concatenating Strings Efficiently

StringBuilders should be reserved when the number of concatenations is unknown or large. 
Strings are immutable (not allowed to be changed). 

Dim sampleString As String = "I think the vegetables are : " _

sampleString &= "Tasty"

In the above example, the compiler will create a new string, allocate memory, copy the data from the original string and then copying the new data at the end of the existing string.

For a large number of concatenations, this operation is inefficient.


The performance of a concatenation operation for a String or StringBuilder object depends on how often a memory allocation occurs. A string concatenation operation always allocates memory, whereas a StringBuilder concatenation operation only allocates memory if the StringBuilder object buffer is too small to accommodate the new data.

Dim sampleString As String = "I think the vegetables are : " _

& "Tasty"

The string class is preferable if a fixed number of string objects are concatenated. Individual concatenation operations might be optmized by the compiler into a single operation.

 

Public Function Reproduce(

ByVal source As String,

ByVal iterations As Integer) As String

      Dim sampleStringBuilder As New System.Text.StringBuilder()

        For index As Integer = 0 To iterations

            sampleStringBuilder.Append(source)

        Next

      Return sampleStringBuilder.ToString()

End Function

A StringBuilder implementation is preferred when a large or unknown number of strings needs to be concatenated.


Resources:

http://www.yoda.arachsys.com/csharp/stringbuilder.html

http://msdn.microsoft.com/en-us/library/system.text.stringbuilder.aspx

Query Engine

The Query Engine is a utility I’ve developed that can connect to and perform queries against SQL Server or Oracle databases.

Connecting to  a Data Source

The Query Engine connects to an Oracle or a SQL Server data source via the File->Connect.

This brings up the Data Link properties dialog where connection parameters for either an Oracle or a SQL Server data source may be specified.

The Data Link properties dialog may also be invoked by clicking on the “Connect” icon in the Query Engine toolbar.

Querying Data Objects

Once connected to a database instance, the Query Engine will display all tables found in the specified data source in the table list located at the left.

Double clicking any of these entries will create an SQL select query in the command window and display the corresponding results in the query results grid.

The command window may also be used to specify more advanced SQL Queries.

These queries get executed once the Run command is clicked in the Query menu.

An alternative to this is the F5 button in the keyboard or the Run icon in the toolbar menu.

The Query results are retrieved asynchronously using a background thread.

This operation can be stopped by clicking on the stop icon in the toolbar.

Selecting Columns in Database Objects

Shift Double Clicking on an item in the table list will display the column names that can be selected prior to generating a query in the command window.

The select all button checks all columns for the selected table.

The de-select all button unchecks all columns for the selected table.

The select specified columns will create an SQL select statement which contains all the checked columns in the select columns dialog.

Search values inside Data Objects

Click on the magnifier icon to bring up the search dialog.

The search box accepts an alphanumeric string which is used to evaluate columns of its occurrence.

The search button initiates the search using the specified search string.

The close button closes the search dialog.

The search is asynchronous.

When a search is in progress, the table name and the column where it is found are dumped in the results grid.

Double click on any of the entries in the results grid to issue an automatic query in the command window of the Query Engine form.

This can be done even if a search is currently in progress.

The next button skips the current table and jumps to the next available data object to scan.

There can only be one active search at a time.

The current search needs to be cancelled via the abort button for a new search to be made.

You can also invoke the search dialog via Ctrl+F or via the Tools menu of Query Engine.

Viewing in Card View

Card view allows viewing of records with a large number of columns vertically.

To view records in card view, right click on the grid and then select Card View.

Grouping Records

The Query Engine can group records using a particular column.

This can be enabled via the tools menu.

Once enabled, a band will appear in the grid where columns can be dragged for grouping.

Dragging a column into this band will group the records using that column.

Freezing Columns

A column can be frozen by clicking on the freeze icon. This is the right-most icon beside the column name.

Filtering Rows

Query results can be filtered by specifying the filter condition in a column. To specify a filter condition, click on the filter icon which is the second icon to the right of the column name.

A dropdown appears with a list of choices in which the records may be filtered.

To specify a more complex filter condition, click on the Custom item in the filter dropdown.

Adding Summaries

To add a summary, click on the summary icon for the column that needs to be summarized.

From the dialog, select one or more methods on how to summarize the column.

Clicking the ok button will apply the selection on the column.

Exporting to Excel

To export a query result to excel, click on the Export to excel button in the Query Engine toolbar.
Specify a file name and click on save.

Configuring Query Engine

Clicking on the Tools->Configure menu will bring up the Query Engine configuration screen.

The working directory points to the location that will be used by Query Engine for its processes.

The displayed rows setting controls the maximum rows displayed per query.

This prevents massive datasets from being accidentally loaded to Query Engine.

This can be turned off by specifying a value of 0.

The recommended value is 200,000 rows.

The font setting controls the font that is used for the query editor and the Query Engine grid.

To modify the font, click on the Change button beside the font field.

Clicking Ok will apply the settings to the query editor and the grid.

Cobra Log Zipper

The Cobra Log Zipper is a utility I’ve written that locates the various Cobra log files and zips them to a location specified by the user.

For more information on Deltek Cobra 5, visit:
http://www.deltek.com/products/cobra/default.asp

The tool will automatically work out the list of log file locations once started.

Clicking the zip log files button will compress the log files to the specified location.

By default, the zip will be created in the user’s My Documents folder.

The Cobra Log Zipper Grid

When Cobra Log Zipper starts, it locates all Cobra Log Files in the machine and creates an entry for them in the grid.

The records in this grid will be included in the zip file when the user clicks on the Zip log files button.

The Cobra Log Zipper grid contains five columns.

·         The file name column contains the name of the Cobra log file detected in the system.

·         The last updated column contains the date and time when this file was last written to.

·         The age column describes how long since the file was last written to.

·         The size column specifies how large the Cobra log file entry is.

·         The location column shows the full path where the Cobra log file was found.

Previewing Cobra Log Files

The Open in notepad button will open the selected Cobra log file using Windows notepad.

This can also be done by double clicking on the Cobra Log Zipper grid.

The open log folder will open the selected Cobra log file’s directory using Windows Explorer.

A right click in the CobraLogZipper grid will open up a context menu which either option can be selected.

Specifying a destination folder

By default the Cobra Log Zipper will place zipped files in the My Documents folder.

This can be changed by manually typing in the path inside the destination folder text box.

The background color will change to signal a valid or an invalid folder entry.

The textbox will offer suggestions as you type based on the folders that exist in the system.

The destination folder can also be specified via a folder browser dialog by clicking on the ellipsis button beside the textbox.

The folder browser dialog allows the user to create and specify an output folder where the Cobra Log Zipper will place its generated file.

The contents of the output folder can be viewed by clicking on the Open output folder in explorer icon.

Zipping the Log Files

Clicking on the zip log files creates a zip file containing the Cobra Log files outlined in the Cobra Log Zipper grid and places them in the specified destination folder.

Clicking the Zip log files button invokes a results dialog which contains details on the zipping process.

The contents of the output folder can be viewed from this screen by clicking on the Open output folder icon.

Cobra API Builder

The Cobra API Builder is a tool that assists in creating and running scripts for the Cobra 5 API.
For more information on Deltek Cobra 5, visit:
http://www.deltek.com/products/cobra/default.asp

A script can be added by using the add script button (ctrl+shift+a).
An integrated help system enables displaying of hints by pressing the question mark key.

To select a script, pick an entry in the dropdown list.

If the script needed to be run is known, simply type in the name of the script.

Choosing a script in the dropdown control will display the parameters in the panel below it.

Selecting ok will populate the main editor window with the necessary details to run the process.

The script can be saved by clicking on the save icon or hitting Ctrl+S on the keyboard.

Creating a batch file to run the script

Click on the Create/Configure batch script icon to configure a batch file that can be used to run the script. This invokes the dialog which allows the necessary credential to be specified.

The batch file name defaults to the name of the saved file with an extension of bat.

The credential fields must contain the cobra login details that will be used to run the script.

The Cobra API Location must point to the location of the Cobra.Api.exe which is the main executable required to run the script.

This will generate a batch file in the same folder where the script is saved.

Running the script via the API Builder

Click on the Run batch script icon or press F5 on the keyboard to run the script using the API Builder. This invokes a dialog which allows the necessary credential to be specified.

After the run has completed, Cobra API Builder will open the Cobra API log file which contains the results of the run.

This API log file can be viewed anytime via the view Menu.

Auto complete

As of Cobra API Builder version 1.0.4, the main script editor window has been added the capability to use basic auto complete to guide the user in building the API script.

Scheduling a Process

The Cobra API Builder allows sending the current script as a job to be run by the Windows Task Scheduler.

Once a script has been setup, click on the schedule button in the toolbar.