Martin Hořeňovský 1079da4c5f Avoid quadratic JSON array parse behaviour in catch_discover_tests ...

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.

2026-07-26 19:51:58 +02:00

..

ExtraTests

Fix --warn InfiniteGenerators firing even if the generator was filtered

2026-07-07 14:09:11 +02:00

SelfTest

Better support for infs and NaNs in JSON writer

2026-07-23 14:26:26 +02:00

TestScripts

Avoid quadratic JSON array parse behaviour in catch_discover_tests

2026-07-26 19:51:58 +02:00

BUILD.bazel

Support for constexpr matchers in C++20 (P0784)

2026-05-12 11:05:02 +02:00

CMakeLists.txt

Avoid quadratic JSON array parse behaviour in catch_discover_tests

2026-07-26 19:51:58 +02:00

meson.build

Support for constexpr matchers in C++20 (P0784)

2026-05-12 11:05:02 +02:00