From 0034fb27458d62e1fcad59aed97c2f29e59bd329 Mon Sep 17 00:00:00 2001
From: Nicholas Lundgaard <nalundgaard@gmail.com>
Date: Tue, 22 Aug 2017 13:08:05 -0500
Subject: [PATCH] Add support for Erlang 20

* adds support for building with Erlang 20, with compiler warnings addressed (primarily in test module)
* relaxes `require_otp_vsn` to be future (expected) compatible
* adds Erlang 20 to travis config
---
 .travis.yml        |  1 +
 rebar.config       |  5 +++--
 src/jsn.erl        |  2 +-
 test/jsn_tests.erl | 37 +++++++++++++++++++++++++------------
 4 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index a411a28..952cdff 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,6 @@
 language: erlang
 otp_release:
+  - 20.0
   - 19.3
   - 18.3
   - 17.5
diff --git a/rebar.config b/rebar.config
index 046a6af..110b2a5 100644
--- a/rebar.config
+++ b/rebar.config
@@ -1,10 +1,11 @@
-{require_otp_vsn, "R1[456]|1[789]"}.
+{require_otp_vsn, "R1[456]|^[0-9]+"}.
 
 {deps, [
     {jsonx, ".*", {git, "https://github.com/iskra/jsonx.git", {branch, master}}}
 ]}.
 
-{erl_opts, [inline_list_funcs,
+{erl_opts, [{platform_define, "^1[89]|^[2-9][0-9]+", has_rand},
+            inline_list_funcs,
             warn_deprecated_function,
             warn_export_vars,
             warn_obsolete_guard,
diff --git a/src/jsn.erl b/src/jsn.erl
index 5cdffa2..6ef726f 100644
--- a/src/jsn.erl
+++ b/src/jsn.erl
@@ -36,7 +36,7 @@
 -export([as_proplist/1, from_proplist/1, from_proplist/2]).
 
 -ifdef(TEST).
--compile([export_all, debug_info]).
+-compile([export_all, nowarn_export_all, debug_info]).
 -endif.
 
 %%==============================================================================
diff --git a/test/jsn_tests.erl b/test/jsn_tests.erl
index 3b65a75..0815e9d 100644
--- a/test/jsn_tests.erl
+++ b/test/jsn_tests.erl
@@ -2,17 +2,30 @@
 -module(jsn_tests).
 
 -ifdef(TEST).
--compile([export_all, debug_info]).
+-compile([export_all, nowarn_export_all, debug_info]).
 -include_lib("eunit/include/eunit.hrl").
 
 -include("jsn.hrl").
 
+%%==============================================================================
+%% random number compatibility
+%%==============================================================================
+
+-spec rand_uniform(Min :: integer(), Max :: integer()) -> integer().
+-ifdef(has_rand).
+rand_uniform(Min, Max) when Min =< Max ->
+    rand:uniform(Max - Min + 1) + Min - 1.
+-else.
+rand_uniform(Min, Max) when Min =< Max ->
+    crypto:rand_uniform(Min, Max).
+-endif.
+
 %%==============================================================================
 %% json object generation
 %%==============================================================================
 
 generate_json_object(Depth, Options) ->
-    PairNumber = crypto:rand_uniform(5, 10),
+    PairNumber = rand_uniform(5, 10),
     Pairs = [
         { generate_json_key(6), generate_json_value(Depth-1, Options)}
         || _ <- lists:seq(1,PairNumber)
@@ -22,7 +35,7 @@ generate_json_object(Depth, Options) ->
 
 generate_json_key(I) ->
     JsonString = generate_json_string(I),
-    case crypto:rand_uniform(1, 2) of
+    case rand_uniform(1, 2) of
         1 -> JsonString;
         2 -> binary_to_atom(JsonString, utf8)
     end.
@@ -31,9 +44,9 @@ generate_json_key(I) ->
 generate_json_string(I) ->
     Letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
               "0123456789!@#$%^&*()_+-=[]{}/\\|<>,;'\"`",
-    Length = crypto:rand_uniform(1, I),
+    Length = rand_uniform(1, I),
     list_to_binary([
-        lists:nth(crypto:rand_uniform(1, length(Letters)), Letters)
+        lists:nth(rand_uniform(1, length(Letters)), Letters)
         || _ <- lists:seq(1,Length)
     ]).
 
@@ -42,7 +55,7 @@ generate_json_value(X, _Options) when X =< 0 ->
     generate_json_number();
 
 generate_json_value(Depth, Options) ->
-    case crypto:rand_uniform(1, 6) of
+    case rand_uniform(1, 6) of
         1 -> generate_json_object(Depth, Options);
         2 -> generate_json_array(Depth, Options);
         3 -> generate_json_string(6);
@@ -53,7 +66,7 @@ generate_json_value(Depth, Options) ->
 
 
 generate_json_array(Depth, Options) ->
-    Length = crypto:rand_uniform(0, 10),
+    Length = rand_uniform(0, 10),
     [ generate_json_value(Depth-1, Options) || _ <- lists:seq(1, Length) ].
 
 
@@ -62,17 +75,17 @@ generate_json_number() ->
 
 
 generate_json_number(N) ->
-    case crypto:rand_uniform(1, 2) of
-        1 -> crypto:rand_uniform(1, 2 * N) - N;
+    case rand_uniform(1, 2) of
+        1 -> rand_uniform(1, 2 * N) - N;
         2 ->
-            M = crypto:rand_uniform(1, 9999999999999),
-            crypto:rand_uniform(1, N * M) / (M)
+            M = rand_uniform(1, 9999999999999),
+            rand_uniform(1, N * M) / (M)
     end.
 
 
 generate_json_boolean() ->
     Values = ['true', 'false'],
-    lists:nth(crypto:rand_uniform(1, length(Values)), Values).
+    lists:nth(rand_uniform(1, length(Values)), Values).
 
 
 %%==============================================================================