make: implement check-format in POSIX shell

The docker image used for the CI does not contain bash.

2 files changed, 10 insertions, 5 deletions

diff --git a/Makefile b/Makefile
index cdf9647..7d505d4 100644
--- a/Makefile
+++ b/Makefile
@@ -4,19 +4,16 @@ LUA_FILES := $(shell find -name "*.lua" -not -path "./json.lua")
 
 TEST_FILES := $(shell find -name "*_test.lua")
 
-# bash's process substitution is used for check-format
-SHELL := /bin/bash
-
 check: check-luacheck check-format
 
 check-luacheck:
 	luacheck --globals=vis -- $(LUA_FILES)
 
 check-format:
-	for lf in $(LUA_FILES); do diff $$lf <(lua-format $$lf) >/dev/null; done
+	for lf in $(LUA_FILES); do tools/check-format "$${lf}"; done
 
 format:
 	lua-format -i $(LUA_FILES)
 
 test:
-	for tf in $(TEST_FILES); do $$tf; done
+	for tf in $(TEST_FILES); do "$$tf"; done
diff --git a/tools/check-format b/tools/check-format
new file mode 100755
index 0000000..392d023
--- /dev/null
+++ b/tools/check-format
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+LUA_FILE=$1
+lua-format "${LUA_FILE}" > "${LUA_FILE}.fmt"
+diff "${LUA_FILE}" "${LUA_FILE}.fmt"
+RET=$?
+rm "${LUA_FILE}.fmt"
+exit ${RET}