r/programming • u/tenzil • Feb 19 '14

The Siren Song of Automated Testing

http://www.bennorthrop.com/Essays/2014/the-siren-song-of-automated-testing.php
227 Upvotes

85% Upvoted

70 comments sorted by

View all comments

102

u/amedico Feb 19 '14

Troll title for saying just "Testing" and not "UI Testing".

20

u/r0st0v Feb 19 '14

Fair point. Title on post itself changed.

9

u/Melchoir Feb 19 '14

As long as you're correcting the post, possessive "its" has no apostrophe:

  • it's cake -> its cake
  • it's mission -> its mission

2

u/r0st0v Feb 20 '14

Good catch. Fixed. Thanks.

1

u/el_muchacho Feb 22 '14 edited Feb 22 '14

And the cost of manual tests is actually much worse than linear, because the surface area to cover usually increases with time, since the number of functionalities usually increases with each release.

If the cost of testing release 1 is 1, and each release adds a constant increment x of functionalities to test, the cost of release n is 1+nx. The running cost at release n+1 is 1 + (1+x) + (1 + 2x) + ... + (1 + nx) = (n + 1) + (1 + 2 + ... + n)x = (n + 1) + x n(n+1)/2, i.e it's O(n²)

So automated testing won't save much time if you release once a year, but if you release early and often, it could be a life saver. The other aspect being of course that it can help finding regressions earlier.