From 432b5322409d935bcc771e726f472ca573d85457 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Wed, 6 Jul 2022 21:42:12 -0500
Subject: [PATCH] Only use nbsp for old style usage

Fixes #1342. Closes #1343.
---
 NEWS.md                        |  2 ++
 R/rd-usage.R                   | 29 ++++++++++++++++++-----------
 tests/testthat/test-rd-usage.R |  7 ++++++-
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index b3f42b99..2fa44f13 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # roxygen2 (development version)
 
+* Automated usage no longer mangles nbsp in default arguments (#1342).
+
 * Give useful error if `@describeIn` can't combine docs (#1366).
 
 * Code evaluated in inline markdown code chunks and `@eval`/`@evalRd`/
diff --git a/R/rd-usage.R b/R/rd-usage.R
index 3f3163f8..c68f6524 100644
--- a/R/rd-usage.R
+++ b/R/rd-usage.R
@@ -111,8 +111,8 @@ usage_args <- function(args) {
   map_chr(args, arg_to_text)
 }
 
-args_string <- function(x) {
-  sep <- ifelse(x != "", "\u{A0}=\u{A0}", "")
+args_string <- function(x, space = " ") {
+  sep <- ifelse(x != "", paste0(space, "=", space), "")
   arg_names <- escape(auto_backtick(names(x)))
   paste0(arg_names, sep, escape(x))
 }
@@ -127,24 +127,31 @@ args_call <- function(call, args) {
 #' @param suffix Optional suffix, used for replacement functions
 #' @noRd
 wrap_usage <- function(name, format_name, formals, suffix = NULL, width = 80L) {
-  args <- args_string(usage_args(formals))
+  if (roxy_meta_get("old_usage", FALSE)) {
+    # Use nbsp to keep argument name & default value on same line
+    args <- args_string(usage_args(formals), "\u{A0}")
+    x <- args_call(format_name(name), args)
+    out <- wrapUsage(x, width = as.integer(width), indent = 2)
+
+    out <- gsub("\u{A0}", " ", out, useBytes = TRUE)
+    Encoding(out) <- "UTF-8"
+
+    return(rd(paste0(out, suffix)))
+  }
 
-  # Do we need any wrapping?
+  args <- args_string(usage_args(formals))
   bare <- args_call(name, args)
+
   if (!str_detect(bare, "\n") && nchar(bare, type = "width") < width) {
+    # Don't need to wrap
     out <- args_call(format_name(name), args)
-  } else if (roxy_meta_get("old_usage", FALSE)) {
-    x <- args_call(format_name(name), args)
-    out <- wrapUsage(x, width = as.integer(width), indent = 2)
   } else {
+    # Wrap each argument and put on own line
     args <- paste0("  ", args)
     args <- map_chr(args, wrapUsage, width = 90, indent = 4)
     out <- paste0(format_name(name), "(\n", paste0(args, collapse = ",\n"), "\n)")
   }
 
-  out <- gsub("\u{A0}", " ", out, useBytes = TRUE)
-  Encoding(out) <- "UTF-8"
-
   rd(paste0(out, suffix))
 }
 
@@ -153,5 +160,5 @@ wrap_usage <- function(name, format_name, formals, suffix = NULL, width = 80L) {
 # used for testing
 call_to_usage <- function(code, env = pkg_env()) {
   obj <- call_to_object(!!enexpr(code), env)
-  gsub("\u{A0}", " ", as.character(object_usage(obj)))
+  as.character(object_usage(obj))
 }
diff --git a/tests/testthat/test-rd-usage.R b/tests/testthat/test-rd-usage.R
index 4176be52..69f74937 100644
--- a/tests/testthat/test-rd-usage.R
+++ b/tests/testthat/test-rd-usage.R
@@ -354,4 +354,9 @@ test_that("old wrapping style doesn't change unexpectedly", {
   })
 })
 
-
+test_that("preserves non-breaking-space", {
+   expect_equal(
+     call_to_usage(f <- function(a = "\u{A0}") {}),
+     'f(a = "\u{A0}")'
+   )
+})