test: use $TEST_TIMEOUT to specify timeout

cmake/RunTests.cmake

@@ -49,6 +49,10 @@ endif()
 set(ENV{TMPDIR} "${BUILD_DIR}/Xtest_tmpdir/${TEST_PATH}")
 execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory $ENV{TMPDIR})
 
+if(NOT DEFINED ENV{TEST_TIMEOUT} OR "$ENV{TEST_TIMEOUT}" STREQUAL "")
+  set(ENV{TEST_TIMEOUT} 1200)
+endif()
+
 set(ENV{SYSTEM_NAME} ${CMAKE_HOST_SYSTEM_NAME})  # used by test/helpers.lua.
 execute_process(
   COMMAND ${BUSTED_PRG} -v -o test.busted.outputHandlers.${BUSTED_OUTPUT_TYPE}
@@ -58,7 +62,7 @@ execute_process(
     --lpath=?.lua
     ${BUSTED_ARGS}
     ${TEST_PATH}
-  TIMEOUT 1200
+  TIMEOUT $ENV{TEST_TIMEOUT}
   WORKING_DIRECTORY ${WORKING_DIR}
   ERROR_VARIABLE err
   RESULT_VARIABLE res

test/README.md

@@ -258,6 +258,9 @@ Number; !must be defined to function properly):
 
 - `TEST_SKIP_FRAGILE` (F) (D): makes test suite skip some fragile tests.
 
+- `TEST_TIMEOUT` (FU) (I): specifies maximum time, in seconds, before the test
+  suite run is killed
+
 - `NVIM_PROG`, `NVIM_PRG` (F) (S): override path to Neovim executable (default
   to `build/bin/nvim`).