- Introduce a new sdssubstr api as a building block for sdsrange.
The API of sdsrange is many times hard to work with and also has
corner case that cause bugs. sdsrange is easy to work with and also
simplifies the implementation of sdsrange.
- Revert the fix to RM_StringTruncate and just use sdssubstr instead of
sdsrange.
- Solve valgrind warnings from the new tests introduced by the previous
PR.
Previously, passing 0 for newlen would not truncate the string at all.
This adds handling of this case, freeing the old string and creating a new empty string.
Other changes:
- Move `src/modules/testmodule.c` to `tests/modules/basics.c`
- Introduce that basic test into the test suite
- Add tests to cover StringTruncate
- Add `test-modules` build target for the main makefile
- Extend `distclean` build target to clean modules too