TESTS: Test scripts risks passing a 'which' out of range to rowOrderStats()

[HenrikBengtsson]

Adopted from an off-line report by @AngelPn:

Issue

Test script https://github.com/HenrikBengtsson/matrixStats/blob/develop/tests/rowOrderStats.R:

matrixStats/tests/rowOrderStats.R

Lines 50 to 54 in 2ef2ab0

	probs <- runif(1)
	which <- round(probs * ncol)
	y0 <- rowOrderStats_R(x, probs = probs)
	y1 <- rowOrderStats(x, which = which)

and test script https://github.com/HenrikBengtsson/matrixStats/blob/2ef2ab0a308ecc07bf7419ea18ac163df6219d17/tests/rowOrderStats_subset.R:

matrixStats/tests/rowOrderStats_subset.R

Lines 21 to 27 in 2ef2ab0

	if (is.null(cols)) which <- round(probs * ncol(x))
	else {
	xxrows <- rows
	suppressWarnings({
	xx <- tryCatch(x[, cols, drop = FALSE], error = function(c) "error")
	if (identical(xx, "error")) which <- 0
	else which <- round(probs * ncol(xx))

tests with a which index that is randomly drawn. However, the way they draw it, risks returning which = 0, which is out of range. It's just by luck from how the initial random seed is set that this is not happening in the current tests.

Action

• Replace probs <- runif(1); which <- round(probs * max) with a better strategy that guarantees that which is in [1,max].