Add tests

tests/testthat/subsetting.txt

@@ -290,6 +290,23 @@ Error: Must extract column with a single valid subscript.
 x Subscript `TRUE` has the wrong type `logical`.
 i It must be numeric or character.
 
+> foo[[-1]]
+Error: Must extract column with a single valid subscript.
+x Subscript `-1` has value -1 but must be a positive location.
+
+> foo[[1.5]]
+Error: Must extract column with a single valid subscript.
+x Can't convert from `1.5` <double> to <integer> due to loss of precision.
+
+> foo[[3]]
+Error: Can't subset columns that don't exist.
+x Location 3 doesn't exist.
+i There are only 2 columns.
+
+> foo[[Inf]]
+Error: Must extract column with a single valid subscript.
+x Can't convert from `Inf` <double> to <integer> due to loss of precision.
+
 > foo[[mean]]
 Error: Must extract column with a single valid subscript.
 x Subscript `mean` has the wrong type `function`.

tests/testthat/test-subsetting.R

@@ -789,6 +789,10 @@ verify_output("subsetting.txt", {
   foo[[1:3]]
   foo[[ letters[1:3] ]]
   foo[[TRUE]]
+  foo[[-1]]
+  foo[[1.5]]
+  foo[[3]]
+  foo[[Inf]]
   foo[[mean]]
   foo[[foo]]