Testing type promotions with dplyr's rbind

test_dplyr_rbind.R

.rbind = function(x, y)
    tryCatch({
        dplyr::rbind_list(x, y)
        message("OK")
    }, error=function(e) print(e))

message("logical --> integer")
.rbind(data.frame(x=TRUE), data.frame(x=1L))
.rbind(data.frame(x=1L), data.frame(x=TRUE))

message("logical --> numeric")
.rbind(data.frame(x=TRUE), data.frame(x=1.5))
.rbind(data.frame(x=1.5), data.frame(x=TRUE))

message("integer --> numeric")
.rbind(data.frame(x=1L), data.frame(x=1.5))
.rbind(data.frame(x=1.5), data.frame(x=1L))

# Not sure if factor should be promoted to character or character to factor.
# base::rbind seems to keep type of the first argument.
message("factor <--> character")
.rbind(data.frame(x="foo"), data.frame(x="foo", stringsAsFactors=FALSE))
.rbind(data.frame(x="foo", stringsAsFactors=FALSE), data.frame(x="foo"))

message("NA --> integer")
.rbind(data.frame(x=NA), data.frame(x=1L))
.rbind(data.frame(x=1L), data.frame(x=NA))

message("NA --> factor")
.rbind(data.frame(x=NA), data.frame(x="foo"))
.rbind(data.frame(x="foo"), data.frame(x=NA))

message("NA --> numeric")
.rbind(data.frame(x=NA), data.frame(x=1.5))
.rbind(data.frame(x=1.5), data.frame(x=NA))

message("NA --> character")
.rbind(data.frame(x=NA), data.frame(x="foo", stringsAsFactors=FALSE))
.rbind(data.frame(x="foo", stringsAsFactors=FALSE), data.frame(x=NA))