test functions

R/function.R

@@ -8,7 +8,14 @@ parse_args <- function(x, mc) {
         )
     }
     args <- lapply(names(fmls), function(n) {
-        fmls[[n]]$check(eval(mc[[n]]))
+        tryCatch(
+            {
+                fmls[[n]]$check(eval(mc[[n]]))
+            },
+            error = function(e) {
+                stop("Invalid argument '", n, "': ", e$message, call. = FALSE)
+            }
+        )
     })
     names(args) <- names(fmls)
     args
@@ -48,6 +55,10 @@ ts_function <- function(f, ..., result = NULL) {
         stop("Invalid return type")
     }
 
+    if (length(args) == 0) {
+        args <- lapply(formals(f), eval)
+    }
+
     fn <- function(...) {
         mc <- match.call(f)
         x <- parse_args(args, mc)

tests/testthat/test-functions.R

@@ -1,12 +1,12 @@
 # # optional, check arguments - useful for debugging/development
 # check_args(match.call(), formals())
 
-# test_that("function definitions", {
-#     add <- ts_fun(
-#         function(a = ts_numeric(1), b = ts_numeric(1)) a + b,
-#         result = ts_numeric(1)
-#     )
+test_that("function definitions", {
+    add <- ts_function(
+        function(a = ts_numeric(1), b = ts_numeric(1)) a + b,
+        result = ts_numeric(1)
+    )
 
-#     expect_equal(add(1, 2), 3)
-#     expect_error(add("a", 2))
-# })
+    expect_equal(add(1, 2), 3)
+    expect_error(add("a", 2))
+})