Avoid use of _ in these tests

Closes #260

Anticipates a possible future in which `_` is the placeholder for the native pipe.

These are better as snapshot tests anyway.

NEWS.md

@@ -1,5 +1,7 @@
 # glue (development version)
 
+* Modify a test for better forward compatibility with R.
+
 # glue 1.6.1
 
 * glue now registers its custom knitr engines in a way that is more robust to namespace-loading edge cases that can arise during package installation (#254).

tests/testthat/_snaps/color.md

@@ -1,3 +1,26 @@
+# glue_col() errors for invalid syntax or when color_fun can't be found
+
+    Code
+      glue_col("{%}")
+    Error <simpleError>
+      <text>:1:1: unexpected input
+      1: %
+          ^
+
+---
+
+    Code
+      glue_col("{foo %}")
+    Error <simpleError>
+      object 'foo' of mode 'function' was not found
+
+---
+
+    Code
+      glue_col("{foo %}")
+    Error <simpleError>
+      object 'foo' of mode 'function' was not found
+
 # glue_col() can exploit the `.literal` argument
 
     Code

tests/testthat/test-color.R

@@ -43,14 +43,15 @@ test_that("glue_col() works on nested colors", {
 })
 
 test_that("glue_col() errors for invalid syntax or when color_fun can't be found", {
-    expect_error(glue_col("{_}"), "unexpected input")
-    expect_error(glue_col("{foo _}"), "object 'foo' of mode 'function' was not found")
+  expect_snapshot(error = TRUE, glue_col("{%}"))
 
-    foo <- 1
-    expect_error(glue_col("{foo _}"), "object 'foo' of mode 'function' was not found")
+  expect_snapshot(error = TRUE, glue_col("{foo %}"))
 
-    foo <- crayon::blue
-    expect_identical(glue_col("{foo _}"), as_glue(foo("_")))
+  foo <- 1
+  expect_snapshot(error = TRUE, glue_col("{foo %}"))
+
+  foo <- crayon::blue
+  expect_identical(glue_col("{foo %}"), as_glue(foo("%")))
 })
 
 test_that("glue_data_col() works", {