From 2e2c7d47031e6ade0d67caeaa9cb77d76e2da6dc Mon Sep 17 00:00:00 2001
From: vkatsuba <v.katsuba.dev@gmail.com>
Date: Fri, 7 May 2021 00:12:25 +0300
Subject: [PATCH] Fixes #81: add parentheses to macros inside of binaries

---
 src/formatters/default_formatter.erl    | 12 +++++++++---
 test_app/after/src/macros_in_binary.erl |  9 +++++++++
 test_app/src/macros_in_binary.erl       |  9 +++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 test_app/after/src/macros_in_binary.erl
 create mode 100644 test_app/src/macros_in_binary.erl

diff --git a/src/formatters/default_formatter.erl b/src/formatters/default_formatter.erl
index 759d4d1..1fbafe3 100644
--- a/src/formatters/default_formatter.erl
+++ b/src/formatters/default_formatter.erl
@@ -70,7 +70,8 @@
          truncate_strings = false :: boolean(),
          parenthesize_infix_operations = false :: boolean(),
          empty_lines = [] :: [pos_integer()],
-         encoding = epp:default_encoding() :: epp:source_encoding()}).
+         encoding = epp:default_encoding() :: epp:source_encoding(),
+         in = undefined :: atom()}).
 
 set_prec(Ctxt, Prec) ->
     Ctxt#ctxt{prec = Prec}.    % used internally
@@ -489,7 +490,7 @@ lay_no_comments(Node, Ctxt) ->
             beside(D, lay_text_float("."));
         binary ->
             Ctxt1 = reset_prec(Ctxt),
-            Es = lay_items(erl_syntax:binary_fields(Node), Ctxt1, fun lay/2),
+            Es = lay_items(erl_syntax:binary_fields(Node), Ctxt1#ctxt{in = binary}, fun lay/2),
             beside(lay_text_float("<<"), beside(Es, lay_text_float(">>")));
         binary_field ->
             Ctxt1 = set_prec(Ctxt, max_prec()),
@@ -601,7 +602,12 @@ lay_no_comments(Node, Ctxt) ->
                     Args ->
                         lay_application(N, Args, Ctxt1)
                 end,
-            D1 = beside(lay_text_float("?"), D),
+            D1 = case Ctxt1#ctxt.in of
+                    binary ->
+                        beside(lay_text_float("(?"), beside(D, lay_text_float(")")));
+                    _ ->
+                        beside(lay_text_float("?"), D)
+                end,
             maybe_parentheses(D1, 0, Ctxt1);
         parentheses ->
             D = lay(erl_syntax:parentheses_body(Node), reset_prec(Ctxt)),
diff --git a/test_app/after/src/macros_in_binary.erl b/test_app/after/src/macros_in_binary.erl
new file mode 100644
index 0000000..2385b5c
--- /dev/null
+++ b/test_app/after/src/macros_in_binary.erl
@@ -0,0 +1,9 @@
+-module(macros_in_binary).
+
+-export([chunkify/1]).
+
+-define(CHUNK_SIZE, 65535 - 1).
+-define(CONCAT(A, B), <<A/binary, B/binary>>).
+
+chunkify(<<Binary:(?CHUNK_SIZE)/binary, Rest/binary>>) ->
+    {<<(?CONCAT(Binary, Rest))/binary>>, <<(?CONCAT(Binary, Rest))/binary>>}.
diff --git a/test_app/src/macros_in_binary.erl b/test_app/src/macros_in_binary.erl
new file mode 100644
index 0000000..9437582
--- /dev/null
+++ b/test_app/src/macros_in_binary.erl
@@ -0,0 +1,9 @@
+-module(macros_in_binary).
+
+-export([chunkify/1]).
+
+-define(CHUNK_SIZE, 65535 - 1).
+-define(CONCAT(A, B), <<A/binary, B/binary>>).
+
+chunkify(<<Binary:(?CHUNK_SIZE)/binary, Rest/binary>>) ->
+    {<<(?CONCAT(Binary, Rest))/binary>>, <<?CONCAT(Binary, Rest)/binary>>}.