fix old tests

Author: MichaelChirico

inst/tests/tests.Rraw

@@ -17986,9 +17986,9 @@ test(2230.2, setDF(merge(DT, y, by="k2", incomparables=c(NA,4))),    merge(x, y,
 test(2230.3, setDF(merge(DT, y, by="k2", incomparables=c(4,5))),     merge(x, y, by="k2", incomparables=c(4,5)))
 test(2230.4, setDF(merge(DT, y, by="k2", incomparables=c(1, NA, 4, 5))), merge(x, y, by="k2", incomparables=c(1,NA,4,5)))
 test(2230.5, setDF(merge(DT, y, by="k2", incomparables=c(NA, 3, 4, 5))), merge(x, y, by="k2", incomparables=c(NA,3,4,5)))
-test(2230.6, merge(DT, y, by="k2", unk=1), merge(DT, y, by="k2"), warning="Unknown argument 'unk' has been passed.")
+test(2230.6, merge(DT, y, by="k2", unk=1), merge(DT, y, by="k2"), warning="1 unknown keyword argument which will be ignored: [unk]")
 test(2230.7, merge(DT, y, by="k2", NULL, NULL, FALSE, FALSE, FALSE, TRUE, c(".x", ".y"), TRUE, getOption("datatable.allow.cartesian"), NULL, 1L),
-             merge(DT, y, by="k2"), warning=c("Supplied both `by` and `by.x`/`by.y`. `by` argument will be ignored.", "Passed 1 unknown and unnamed arguments."))
+             merge(DT, y, by="k2"), warning=c("Supplied both `by` and `by.x`/`by.y`. `by` argument will be ignored.", "1 unnamed arguments wound up in '...' and will be ignored."))
 
 # weighted.mean GForce optimized, #3977
 old = options(datatable.optimize=1L)