Read up on compass variation or declination. For example, this NOAA site provides some useful information.
Mariners use the magnetic variation to compute the difference between True north (i.e., aligned with the grid on the chart) and Magnetic north (i.e., aligned with the compass.)
The essential use …
Another case study on TDRE.
Provided: 2,938 lines of Python code which process a handful of large files to create a number of outputs. [Details can't be disclosed.]
Objective: Refactor to distinguish between the overall sequence of transformational steps and the details of each individual step.
The code …
Unit test coverage is a politically sensitive issue.
If you don't like (or want) unit testing, you set the threshold really high. 100% code coverage, or worse, 100% logic path coverage. Since these goals are difficult to achieve, the whole unit testing business can be made to go away.
If …
more ...Check out this StackOverflow "question": Does anyone have metrics on the utility of formal Unit Testing? . While -- technically -- it does have a question, it's more of a rant against formal unit testing than a proper question.
Here's the conflation comment. "I've worked with developers who never caught any errors in …
more ...Here's a recipe for transforming a pile of similarly-formatted source spreadsheets into a suite of unittest test cases.
The customer sent a screen grab from an accounting desktop application with a couple of rows highlighted. They claim that the application I reverse engineered from C and rewrote in Java didn't work for this one case.
Step 1. Get clarification on the screen grab information. The data labels don't …
more ...First, read Bach's Heuristic Risk-Based Testing . Clear and simple.
Then, read Amland and Garborgsv Risk-Based Testing and Metrics . Not so clear -- probability gets folded in, confusing the issue. Also check out Schaefer's Risk-Based Testing . Probabilities are waved around like they're important. They aren't.
Risk management shouldn’t be confused with …
more ...Here's one recent example of a significant bug.
The code said A is not NULL OrElse A != " ", which doesn't do anything useful. If A has non-NULL data, this is true. The second part of the clause (A != " ") is only evaluated if A is NULL. If A is NULL, no other …
more ...See Scott Ambler's article in Dr. Dobb's Journal , "Scaling Test-Driven Development ".
Recently, I'd seen some notes in SD Times on a similar theme, and blogged that in Not Quite Following the Book .
Ambler's point seems to be the same as Coplien's: "High-level architecture sketches created during your Iteration 0 envisioning …
more ...I can't find all of the Better Software Magazine articles on the Sticky Minds web site, so I can't provide a permalink. But look for "A Story About User Stories and Test Driven Development". It's good stuff, weighing out the good and bad features of "by-the-book" TDD.
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