allow , and %>% on preceding line before {

NEWS.md

@@ -11,7 +11,8 @@
 * Rename `semicolon_terminator_linter` to `semicolon_linter` for better consistency. `semicolon_terminator_linter` survives but is marked for deprecation. The new linter also has a new signature, taking arguments `allow_compound` and `allow_trailing` to replace the old single argument `semicolon=`, again for signature consistency with other linters.
 * Combined several curly brace related linters into a new `brace_linter` (#1041, @AshesITR):
   + `closed_curly_linter()`, also allowing `}]` in addition to `})` and `},` as exceptions.
-  + `open_curly_linter()`, no longer linting unnecessary trailing whitespace
+  + `open_curly_linter()`, no longer linting unnecessary trailing whitespace and also allowing `,` and `%>%` on
+    preceding lines as exceptions. (#487, #1028)
   + `paren_brace_linter()`, also linting `if`/`else` and `repeat` with missing whitespace
   + Require `else` to come on the same line as the preceding `}`, if present (#884, @michaelchirico)
   + Require functions spanning multiple lines to use curly braces (@michaelchirico)

R/brace_linter.R

@@ -34,6 +34,10 @@ brace_linter <- function(allow_single_line = FALSE) {
       "not(
         (@line1 = parent::expr/preceding-sibling::OP-LEFT-BRACE/@line1) or
         (@line1 = following-sibling::expr/OP-LEFT-BRACE/@line1)
+      )",
+      # allow , and %>% on preceding line
+      "not(
+        @line1 = parent::expr/preceding-sibling::*[1][self::OP-COMMA or (self::SPECIAL and text() = '%>%')]/@line2 + 1
       )"
     ))
 

tests/testthat/test-brace_linter.R

@@ -83,6 +83,53 @@ test_that("brace_linter lints braces correctly", {
     linter
   )
 
+  # ,<\n>{ is allowed
+  expect_lint(
+    trim_some("
+      switch(
+        x,
+        'a' = do_something(x),
+        'b' = do_another(x),
+        {
+          do_first(x)
+          do_second(x)
+        }
+      )
+    "),
+    NULL,
+    linter
+  )
+
+  expect_lint(
+    trim_some("
+      fun(
+        'This is very very very long text.',
+        {
+          message('This is the code.')
+          message('It\\'s stupid, but proves my point.')
+        }
+      )
+    "),
+    NULL,
+    linter
+  )
+
+  # %>%\n{ is allowed
+  expect_lint(
+    trim_some("
+    letters %>%
+      {
+        tibble(
+          lo = .,
+          hi = toupper(.)
+        )
+      } %>%
+      mutate(row_id = row_number())
+    "),
+    NULL,
+    linter
+  )
+
   # {{ }} is allowed
   expect_lint("{{ x }}", NULL, linter)