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Martin Hořeňovský
1079da4c5f
Using CMake's `string(JSON` to parse JSON array leads to quadratic running time in number of tests, see https://gitlab.kitware.com/cmake/cmake/-/work_items/27985 This leads to _terrible_ runtime for `catch_discover_tests` when called on binaries with lot of tests (1k+). To get reasonable runtimes, we have to avoid using `string(JSON` to parse out the individual test objects from the array with all tests. This commit replaces the sane approach of using real JSON parser with a set of terrible hacks, where we use CMake's string APIs to split the JSON array on what looks like object boundary (`}<ws>*,<ws>*{`), and then checking whether the resulting thing can be parsed as JSON object. If not, we append the next piece and check again. And again, and again, until we get a proper JSON object. This is all around a hilariously terrible idea, however: 1) It works in practice for all tested inputs. 2) It improves the time it takes to run `catch_discover_tests` on binary with 1k tests from 4.2s to 1.1s and 2k tests from 16s to 3.9s.