preserve status quo and prevent new line breaks with {{.

R/rules-line-break.R

@@ -16,11 +16,10 @@ set_line_break_around_comma <- function(pd) {
   pd
 }
 
-style_line_break_around_curly <- function(strict, pd) {
+style_line_break_around_curly <- function(strict, curly_curly_has_linebreak, pd) {
   if (is_curly_expr(pd) && nrow(pd) > 2) {
-    closing_before <- pd$token == "'}'"
-    opening_before <- (pd$token == "'{'") & (pd$token_after != "COMMENT")
-    to_break <- lag(opening_before, default = FALSE) | closing_before
+    to_break <- to_break_curly_inner(pd, strict, curly_curly_has_linebreak) &
+      to_break_curly_outer(pd, strict, curly_curly_has_linebreak)
     len_to_break <- sum(to_break)
     pd$lag_newlines[to_break] <- ifelse(rep(strict, len_to_break),
       1L,
@@ -30,6 +29,42 @@ style_line_break_around_curly <- function(strict, pd) {
   pd
 }
 
+
+to_break_curly_inner <- function(pd, strict, curly_curly_has_linebreak) {
+  closing_before <- (pd$token == "'}'") &
+    if (!curly_curly_has_linebreak) {
+      pd$token_after != "'}'"
+    } else {
+      TRUE
+    }
+  opening_before <- (pd$token == "'{'") &
+    (pd$token_after != "COMMENT") &
+    if (!curly_curly_has_linebreak) {
+      pd$token_before != "'{'"
+    } else {
+      TRUE
+    }
+  lag(opening_before, default = FALSE) | closing_before
+}
+
+to_break_curly_outer <- function(pd, strict, curly_curly_has_linebreak) {
+  closing_before <- (pd$token == "'}'") &
+    if (!curly_curly_has_linebreak) {
+      pd$token_before != "'}'"
+    } else {
+      TRUE
+    }
+
+  opening_before <- (pd$token == "'{'") &
+    (pd$token_after != "COMMENT") &
+    if (!curly_curly_has_linebreak) {
+      pd$token_after != "'{'"
+    } else {
+      TRUE
+    }
+  lag(opening_before, default = FALSE) | closing_before
+}
+
 # if ) follows on }, don't break line
 remove_line_break_before_round_closing_after_curly <- function(pd) {
   round_after_curly <- pd$token == "')'" & (pd$token_before == "'}'")

R/style-guides.R

@@ -126,7 +126,7 @@ tidyverse_style <- function(scope = "tokens",
       remove_line_break_before_round_closing_fun_dec =
         if (strict) remove_line_break_before_round_closing_fun_dec,
       style_line_break_around_curly = partial(style_line_break_around_curly,
-        strict
+        strict = strict, curly_curly_has_linebreak = !strict
       ),
       set_line_break_after_opening_if_call_is_multi_line = if (strict)
         partial(

tests/testthat/helpers-curly-culry.R

@@ -0,0 +1,20 @@
+style_text_without_curly_curly <- function(text,
+                                           ...,
+                                           style = tidyverse_style,
+                                           transformers = style(...),
+                                           include_roxygen_examples = TRUE) {
+  dots <- list(...)
+  if ("strict" %in% names(dots)) {
+    strict <- dots$strict
+  } else {
+    strict <- TRUE
+  }
+  transformers$line_break$style_line_break_around_curly <-
+    purrr::partial(style_line_break_around_curly,
+      curly_curly_has_linebreak = TRUE, strict = strict
+    )
+  style_text(text, ...,
+    style = NULL, transformers = transformers,
+    include_roxygen_examples = include_roxygen_examples
+  )
+}

tests/testthat/test-indention_curly.R

@@ -3,22 +3,22 @@ context("indent curly brackets")
 test_that("indention on one-liner curley only is not changed", {
   expect_warning(test_collection("indention_curly_brackets",
                                  "one_line_curly",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
 })
 
 test_that("indention with multi-line curley only is correct", {
   expect_warning(test_collection("indention_curly_brackets",
                                  "multi_line_curly_only",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
 })
 
 
 test_that("indention with multi-line curley and round is correct", {
   expect_warning(test_collection("indention_curly_brackets",
                                  "multi_line_curly_round_only",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
 })
 
@@ -28,10 +28,10 @@ test_that(paste("complete styling via top level api is correct",
                 "(round, curly, spacing)"), {
   expect_warning(test_collection("indention_curly_brackets",
                                  "multi_line_curly_round_spacing",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
   expect_warning(test_collection("indention_curly_brackets",
                                  "multi_line_curly_while_for_if_fun",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
 })

tests/testthat/test-indention_multiple.R

@@ -14,15 +14,15 @@ test_that("multiple round brackets don't cause extraindention", {
 test_that("multiple curly brackets don't cause extraindention", {
   expect_warning(test_collection("indention_multiple",
                                  "curly_only",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
 })
 
 
 test_that("multiple curly and round brackets don't cause extraindention", {
   expect_warning(test_collection("indention_multiple",
                                  "curly_and_round",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 
 })
 
@@ -46,7 +46,7 @@ test_that("if and ifelse interacting with curly braces works", {
 test_that("edge cases work", {
   expect_warning(test_collection("indention_multiple",
                                  "edge_strict",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
 })
 
 test_that("token / braces interaction works", {

tests/testthat/test-token_adding_removing.R

@@ -8,9 +8,10 @@ test_that("other manipulations are correct (add braces, semi-colon etc.)", {
 
 test_that("braces in if-else clause are added correctly", {
   expect_warning(test_collection("token_adding_removing", "if_else_strict",
-                                 transformer = style_text), NA)
+                                 transformer = style_text_without_curly_curly), NA)
   expect_warning(test_collection("token_adding_removing", "if_else_non_strict",
-                                 transformer = style_text, strict = FALSE), NA)
+                                 transformer = style_text,
+                                 strict = FALSE), NA)
   expect_warning(test_collection("token_adding_removing", "if-else-comma",
                                  transformer = style_text, strict = TRUE), NA)
 

tests/testthat/test-unindention.R

@@ -3,7 +3,7 @@ context("unindention")
 test_that("round brackets are unindented correctly", {
   expect_warning(test_collection("unindention",
                                  "mixed",
-                                 transformer = style_text,
+                                 transformer = style_text_without_curly_curly,
                                  write_back = TRUE), NA)
 })