fix: relocate() works when .before and .after called in a function

NEWS.md

@@ -1,3 +1,10 @@
+# poorman 0.2.7.9000 (devel)
+
+The following fixes were also implemented:
+
+* `relocate()` now works correctly when its arguments `.before` and `.after`
+  are passed through a function (#114, @etiennebacher).
+
 # poorman 0.2.6
 
 This update adds the following features:

R/relocate.R

@@ -51,8 +51,26 @@ relocate.data.frame <- function(.data, ..., .before = NULL, .after = NULL) {
   data_names <- colnames(.data)
   col_pos <- select_positions(.data, ...)
 
-  if (!missing(.before)) .before <- colnames(.data)[eval_select_pos(.data, substitute(.before))]
-  if (!missing(.after)) .after <- colnames(.data)[eval_select_pos(.data, substitute(.after))]
+  if (!missing(.before)) {
+    x <- try(eval(.before), silent = TRUE)
+    if (inherits(x, "try-error")) {
+      .before <- colnames(.data)[eval_select_pos(.data, substitute(.before))]
+    } else if (is.null(x)) {
+      .after <- NULL
+    } else {
+      .before <- colnames(.data)[eval_select_pos(.data, .before)]
+    }
+  }
+  if (!missing(.after)) {
+    x <- try(eval(.after), silent = TRUE)
+    if (inherits(x, "try-error")) {
+      .after <- colnames(.data)[eval_select_pos(.data, substitute(.after))]
+    } else if (is.null(x)) {
+      .after <- NULL
+    } else {
+      .after <- colnames(.data)[eval_select_pos(.data, .after)]
+    }
+  }
 
   has_before <- !is.null(.before)
   has_after <- !is.null(.after)

inst/tinytest/test_relocate.R

@@ -44,3 +44,23 @@ expect_error(
   mtcars %>% relocate(gear, .after = mpg, .before = cyl),
   info = "relocate() fails when .after and .before are both given"
 )
+
+myFun <- function(location) {
+  relocate(mtcars, gear, .after = location)
+}
+
+expect_equal(
+  myFun(1),
+  mtcars[, c("mpg", "gear", "cyl", "disp", "hp", "drat", "wt", "qsec", "vs", "am", "carb")],
+  info = "relocate() works when .after is passed through a function"
+)
+
+myFun <- function(location) {
+  relocate(mtcars, gear, .before = location)
+}
+
+expect_equal(
+  myFun(1),
+  mtcars[, c("gear", "mpg", "cyl", "disp", "hp", "drat", "wt", "qsec", "vs", "am", "carb")],
+  info = "relocate() works when .before is passed through a function"
+)