Check compare arguments (#202)

Fixes #181

DESCRIPTION

@@ -19,7 +19,7 @@ Imports:
     diffobj (>= 0.3.4),
     glue,
     methods,
-    rlang (>= 1.0.0)
+    rlang (>= 1.1.0)
 Suggests:
     R6,
     S7,

NEWS.md

@@ -1,5 +1,6 @@
 # waldo (development version)
 
+* `compare()` now gives informative errors if you misspecify the argument types (#181)
 * waldo gains basic support for S7 objects (#200).
 * `as_map()` now preserves attributes (#185).
 * `compare()` can now distinguish between objects that differ only in the value of their S4 bit (#189).

R/compare.R

@@ -92,7 +92,7 @@
 #'   this is R's default behaviour. Use `FALSE` when specifically concerned
 #'   with the encoding, not just the value of the string.
 #' @param list_as_map Compare lists as if they are mappings between names and
-#'   values. Concretely, this drops `NULLs` in both objects and sorts named
+#'   values. Concretely, this drops `NULL`s in both objects and sorts named
 #'   components.
 #' @param quote_strings Should strings be surrounded by quotes? If `FALSE`,
 #'   only side-by-side and line-by-line comparisons will be used, and there's
@@ -137,6 +137,20 @@ compare <- function(x, y, ...,
                     quote_strings = TRUE
                     ) {
 
+  check_string(x_arg)
+  check_string(y_arg)
+  check_number_decimal(tolerance, allow_null = TRUE, min = 0)
+  check_number_whole(max_diffs, min = 1, allow_infinite = TRUE)
+  check_bool(ignore_srcref)
+  if (!isTRUE(ignore_attr) && !is.character(ignore_attr)) {
+    stop_input_type(ignore_attr, "a TRUE or a character vector")
+  }
+  check_bool(ignore_encoding)
+  check_bool(ignore_function_env)
+  check_bool(ignore_formula_env)
+  check_bool(list_as_map)
+  check_bool(quote_strings)
+
   opts <- compare_opts(
     ...,
     tolerance = tolerance,