Reset the indent counter at the end of a line (#243)

* Add a failing test

* Reset indent

Fixes #238

* Tweak whitespace in test

* Fix comment

* Use the hex escape for a space, so editors don't trim this trailing space away

src/trim.c

@@ -48,6 +48,7 @@ SEXP trim_(SEXP x) {
     while (i < str_len) {
       if (xx[i] == '\n') {
         new_line = true;
+        indent = 0;
       } else if (new_line) {
         if (xx[i] == ' ' || xx[i] == '\t') {
           ++indent;

tests/testthat/test-trim.R

@@ -16,7 +16,7 @@ test_that("trim works", {
       "test
     "))
   expect_identical("test",
-    trim("      
+    trim("\x20\x20\x20\x20\x20\x20
       test
       "))
   expect_identical("test",
@@ -154,3 +154,16 @@ test_that("lines containing only indentation are handled properly", {
     "a\nb\n\nc"
   )
 })
+
+# https://github.com/tidyverse/glue/issues/238
+test_that("indent counter resets at newline", {
+  # whitespace-only line has 1 space < min_indent (which is 2)
+  # comment in trim_() says:
+  # "if the line consists only of tabs and spaces, and if the line is
+  #  shorter than min_indent, copy the entire line"
+  expect_identical(trim("\n \n  abcd"), " \nabcd")
+
+  # whitespace-only line has n spaces, n >= min_indent
+  expect_identical( trim("\n  \n  abcd"),  "\nabcd")
+  expect_identical(trim("\n   \n  abcd"), " \nabcd")
+})