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| -rw-r--r-- | 005-testing-c.7 | 79 | ||||
| -rw-r--r-- | Makefile | 1 |
2 files changed, 80 insertions, 0 deletions
diff --git a/005-testing-c.7 b/005-testing-c.7 new file mode 100644 index 00000000..c3a47c12 --- /dev/null +++ b/005-testing-c.7 @@ -0,0 +1,79 @@ +.Dd December 21, 2018 +.Dt TESTING-C 7 +.Os "Causal Agency" +. +.Sh NAME +.Nm Testing C +.Nd a simple unit testing setup +. +.Sh DESCRIPTION +This is a simple approach +to unit testing in C +that I've used in a couple projects. +At the bottom of a C file +with some code I want to test, +I add: +. +.Bd -literal -offset indent +#ifdef TEST +#include <assert.h> + +int main(void) { + assert(...); + assert(...); +} + +#endif +.Ed +. +.Pp +This file normally produces a +.Pa .o +to be linked into the main binary. +For testing, +I produce separate binaries +and run them with +.Xr make 1 : +. +.Bd -literal -offset indent +TESTS = foo.t bar.t + +\&.SUFFIXES: .t + +\&.c.t: + $(CC) $(CFLAGS) -DTEST $(LDFLAGS) $< $(LDLIBS) -o $@ + +test: $(TESTS) + set -e; $(TESTS:%=./%;) +.Ed +. +.Pp +Note that the test binaries +aren't linked with the rest of the code, +so there is potential for simple stubbing or mocking. +. +.Pp +To get the best output +from C's simple +.Xr assert 3 , +it's best to assert the result +of a helper function +which takes the expected output +and the test input, +rather than calling +.Xr assert 3 +inside the helper function. +This way, +the message printed by the assert failure +contains a useful line number +and the expected output +rather than just variable names. +. +.Pp +For a real example, +check +.Lk https://code.causal.agency/june/catgirl/src/branch/master/term.c term.c +from my IRC client project. +. +.Sh AUTHORS +.An C. McEnroe Aq Mt june@causal.agency diff --git a/Makefile b/Makefile index 2fd9b894..8f2a55a1 100644 --- a/Makefile +++ b/Makefile @@ -4,6 +4,7 @@ TXTS += 001-make.txt TXTS += 002-writing-mdoc.txt TXTS += 003-pleasant-c.txt TXTS += 004-uloc.txt +TXTS += 005-testing-c.txt all: $(TXTS) |