Break line in ggplot2 calls

NEWS.md

@@ -1,3 +1,4 @@
+
 # styler 1.2.0.9000
 
 ## Breaking changes
@@ -23,8 +24,10 @@
 
 ## Minor changes and fixes
 
+* lines are now broken after `+` in `ggplot2` calls for `strict = TRUE` (#569).
+
 * `style_file()` and friends now strip `./` in file paths returned invisibly,
-  i.e. `./script.R` becomes `script.R`.
+  i.e. `./script.R` becomes `script.R` (#568).
 
 * function documentation now contains many more linebreaks due to roxygen2 
   update to version 7.0.1 (#566).

R/rules-line-break.R

@@ -273,3 +273,28 @@ remove_line_break_in_empty_fun_call <- function(pd) {
   }
   pd
 }
+
+
+set_linebreak_after_ggplot2_plus <- function(pd) {
+  is_plus_raw <- pd$token == "'+'"
+  if (any(is_plus_raw)) {
+    first_plus <- which(is_plus_raw)[1]
+    next_non_comment <- next_non_comment(pd, first_plus)
+    is_plus_or_comment_after_plus_before_fun_call <-
+      lag(is_plus_raw, next_non_comment - first_plus - 1, default = FALSE) &
+      (pd$token_after == "SYMBOL_FUNCTION_CALL" | pd$token_after == "SYMBOL_PACKAGE")
+    if (any(is_plus_or_comment_after_plus_before_fun_call)) {
+      gg_call <- pd$child[[previous_non_comment(pd, first_plus)]]$child[[1]]
+      if (!is.null(gg_call) && gg_call$text[gg_call$token == "SYMBOL_FUNCTION_CALL"] == "ggplot") {
+        plus_without_comment_after <- setdiff(
+          which(is_plus_raw),
+          which(lead(pd$token == "COMMENT"))
+          )
+
+        pd$lag_newlines[plus_without_comment_after + 1] <- 1L
+      }
+    }
+
+  }
+  pd
+}

R/style-guides.R

@@ -137,7 +137,8 @@ tidyverse_style <- function(scope = "tokens",
         )
       },
       remove_line_break_in_empty_fun_call,
-      add_line_break_after_pipe = if (strict) add_line_break_after_pipe
+      add_line_break_after_pipe = if (strict) add_line_break_after_pipe,
+      set_linebreak_after_ggplot2_plus = if (strict) set_linebreak_after_ggplot2_plus
     )
   }
 

tests/testthat/line_breaks_and_other/ggplot2-in.R

@@ -0,0 +1,31 @@
+# don't remove line break
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  geom_point()
+
+
+# add when unmasked
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) + geom_point()
+
+
+# add when masked
+ggplot2::ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) + geom_point()
+
+# add when masked
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) + ggplot2::geom_point()
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) + # comment
+  ggplot2::geom_point() + g()
+
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  ggplot2::geom_point() + g() # comment
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) + ggplot2::geom_point() + g() # comment
+
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  ggplot2::geom_point() + g()  + geom_oint() # comment

tests/testthat/line_breaks_and_other/ggplot2-out.R

@@ -0,0 +1,40 @@
+# don't remove line break
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  geom_point()
+
+
+# add when unmasked
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  geom_point()
+
+
+# add when masked
+ggplot2::ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  geom_point()
+
+# add when masked
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  ggplot2::geom_point()
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) + # comment
+  ggplot2::geom_point() +
+  g()
+
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  ggplot2::geom_point() +
+  g() # comment
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  ggplot2::geom_point() +
+  g() # comment
+
+
+# add when comment
+ggplot(data = mtcars, mapping = aes(x = mpg, y = vs)) +
+  ggplot2::geom_point() +
+  g() +
+  geom_oint() # comment

tests/testthat/test-line_breaks_and_other.R

@@ -36,3 +36,8 @@ test_that("line break before comma is removed and placed after comma ", {
   expect_warning(test_collection("line_breaks_and_other", "pipe-line",
                                  transformer = style_text), NA)
 })
+
+test_that("line break added for ggplot2 call", {
+  expect_warning(test_collection("line_breaks_and_other", "ggplot2",
+                                 transformer = style_text), NA)
+})