Initialize a test counter, a matrix used to tally tests, their stack depth and the execution order as the trace associated with key is hit. Each test trace is an environment, which allows assignment into a pre-allocated tests matrix with minimall reallocation.




generated with key()


The tests matrix has columns tests, depth and i, corresponding to the test index (the index of the associated test in .counters$tests), the stack depth when the trace is evaluated and the number of traces that have been hit so far during test evaluation.