+
+
+
+Some test suite philosophy:
+
+GDB has an extensive test suite --- around 6300 tests. Every time the
+test suite catches a bug, it's great.
+
+GDB is so complicated that folks are often unable to get a solid
+understanding of the code before making a change --- we just don't
+have time. You'll see people say things like, "Here's a fix for X; it
+doesn't cause any regressions." The subtext is, I made a change that
+looks reasonable, and the test suite didn't complain, so it must be
+okay.
+
+I think this is terrible, because it suggests that the writer is using
+the test suite as a substitute for having a rock-solid explanation of
+why their changes are correct. The problem is that any test suite is
+woefully incomplete. Diligent reasoning about code can catch corner
+conditions or limitations that no test suite will ever find.
+
+
+
+Jim's rule for test suites:
+
+Every test suite failure should be a complete, mysterious surprise,
+never a possibility you were prepared for. Any other attitude
+indicates that you're using the test suite as a crutch, which you need
+only because your understanding is weak.