fix(jsregexp): fix install_jsregexp on Windows

Makefile

@@ -33,36 +33,65 @@ nvim: | ${NVIM_PATH}
 	git -C ${NVIM_MASTER_PATH} fetch origin master --depth 1
 	git -C ${NVIM_MASTER_PATH} checkout FETCH_HEAD
 
-LUASNIP_DETECTED_OS?=$(shell uname)
+LUASNIP_DETECTED_OS?=$(shell uname && false)
 ifeq ($(LUASNIP_DETECTED_OS),Darwin)
 	# flags for dynamic linking on macos, from luarocks
 	# (https://github.com/luarocks/luarocks/blob/9a3c5a879849f4f411a96cf1bdc0c4c7e26ade42/src/luarocks/core/cfg.lua#LL468C37-L468C80)
 	# remove -bundle, should be equivalent to the -shared hardcoded by jsregexp.
 	LUA_LDLIBS=-undefined dynamic_lookup -all_load
 endif
 
-JSREGEXP_PATH=deps/jsregexp
-JSREGEXP005_PATH=deps/jsregexp005
+# On Windows, you may need to set:
+# 	SHELL=C:/path/to/Git/usr/bin/sh.exe
+# 	.SHELLFLAGS=-c
+# 	CC=gcc
+#	NEOVIM_BIN_PATH=C:/path/to/Neovim/bin # contains lua51.dll, or use your own LUA_LDLIBS
+LUASNIP_IS_ON_WINDOWS?=$(OS)
+ifeq ($(LUASNIP_IS_ON_WINDOWS),Windows_NT)
+	# If neovim is installed by scoop, only scoop/shims is exposed. We need to find original nvim/bin that contains lua51.dll
+	# If neovim is installed by winget or other methods, nvim/bin is already included in PATH.
+	# NEOVIM_BIN_PATH?=$(shell type "scoop" >/dev/null 2>&1 && echo "$$(scoop prefix neovim)/bin | sed 's/")
+	NEOVIM_BIN_PATH?=$(shell \
+		if (scoop prefix neovim | grep -v 'Could not find app path for') >/dev/null 2>&1; then \
+			echo "$$(scoop prefix neovim)/bin" | sed 's/\\\\/\\//g' | sed 's/\\(.*\\) \\(.*\\)/"\\1 \\2"/'; \
+		elif which nvim > /dev/null 2>&1; then \
+			dirname "$$(which nvim)" | sed 's/^\\/\\(.\\)\\//\\U\\1:\\//' | sed 's/\\(.*\\) \\(.*\\)/"\\1 \\2"/'; \
+		fi)
+
+	LUA_LDLIBS?=$(if $(strip $(NEOVIM_BIN_PATH)),-L$(NEOVIM_BIN_PATH) -llua51,)
+endif
+
+$(info SHELL is $(SHELL))
+$(info .SHELLFLAGS is $(.SHELLFLAGS))
+$(info CC is $(CC))
+$(info NEOVIM_BIN_PATH is $(NEOVIM_BIN_PATH))
+$(info LUA_LDLIBS is $(LUA_LDLIBS))
+
+# some workaround to empty $(shell command) output on Windows
+# @link: https://stackoverflow.com/questions/74481637/shell-command-in-makefile-returns-empty-on-windows-sometimes
+PROJECT_ROOT:=$(shell pwd && false)
+JSREGEXP_PATH=$(PROJECT_ROOT)/deps/jsregexp
+JSREGEXP005_PATH=$(PROJECT_ROOT)/deps/jsregexp005
 jsregexp:
 	git submodule init
 	git submodule update
-	$(MAKE) "CC=$(CC)" "INCLUDE_DIR=-I'$(shell pwd)/deps/lua51_include/'" LDLIBS="${LUA_LDLIBS}" -C "${JSREGEXP_PATH}"
-	$(MAKE) "CC=$(CC)" "INCLUDE_DIR=-I'$(shell pwd)/deps/lua51_include/'" LDLIBS="${LUA_LDLIBS}" -C "${JSREGEXP005_PATH}"
+	$(MAKE) "CC=$(CC)" "INCLUDE_DIR=-I$(PROJECT_ROOT)/deps/lua51_include/" LDLIBS='$(LUA_LDLIBS)' -C "$(JSREGEXP_PATH)"
+	$(MAKE) "CC=$(CC)" "INCLUDE_DIR=-I$(PROJECT_ROOT)/deps/lua51_include/" LDLIBS='$(LUA_LDLIBS)' -C "$(JSREGEXP005_PATH)"
 
 install_jsregexp: jsregexp
 	# remove old binary.
-	rm "$(shell pwd)/lua/luasnip-jsregexp.so" || true
+	rm "$(PROJECT_ROOT)/lua/luasnip-jsregexp.so" || true
 	# there is some additional trickery to make this work with jsregexp-0.0.6 in
 	# util/jsregexp.lua.
-	cp "$(shell pwd)/${JSREGEXP_PATH}/jsregexp.lua" "$(shell pwd)/lua/luasnip-jsregexp.lua"
+	cp "$(JSREGEXP_PATH)/jsregexp.lua" "$(PROJECT_ROOT)/lua/luasnip-jsregexp.lua"
 	# just move out of jsregexp-directory, so it is not accidentially deleted.
-	cp "$(shell pwd)/${JSREGEXP_PATH}/jsregexp.so" "$(shell pwd)/deps/luasnip-jsregexp.so"
+	cp "$(JSREGEXP_PATH)/jsregexp.so" "$(PROJECT_ROOT)/deps/luasnip-jsregexp.so"
 
 uninstall_jsregexp:
 	# also remove binaries of older version.
-	rm -f "$(shell pwd)/lua/luasnip-jsregexp.so"
-	rm -f "$(shell pwd)/deps/luasnip-jsregexp.so"
-	rm -f "$(shell pwd)/lua/luasnip-jsregexp.lua"
+	rm -f "$(PROJECT_ROOT)/lua/luasnip-jsregexp.so"
+	rm -f "$(PROJECT_ROOT)/deps/luasnip-jsregexp.so"
+	rm -f "$(PROJECT_ROOT)/lua/luasnip-jsregexp.lua"
 
 TEST_07?=true
 TEST_09?=true
@@ -73,11 +102,11 @@ test: nvim install_jsregexp
 	# add our helper-functions to lpath.
 	# exit as soon as an error occurs.
 	unset LUA_PATH LUA_CPATH; \
-	export LUASNIP_SOURCE=$(shell pwd); \
-	export JSREGEXP_ABS_PATH=$(shell pwd)/${JSREGEXP_PATH}; \
-	export JSREGEXP005_ABS_PATH=$(shell pwd)/${JSREGEXP005_PATH}; \
+	export LUASNIP_SOURCE=$(PROJECT_ROOT); \
+	export JSREGEXP_ABS_PATH=$(JSREGEXP_PATH); \
+	export JSREGEXP005_ABS_PATH=$(JSREGEXP005_PATH); \
 	export TEST_FILE=$(realpath ${TEST_FILE}); \
-	export BUSTED_ARGS=--lpath=$(shell pwd)/tests/?.lua; \
+	export BUSTED_ARGS=--lpath=$(PROJECT_ROOT)/tests/?.lua; \
 	set -e; \
 	if ${TEST_07}; then $(MAKE) -C ${NVIM_0.7_PATH} functionaltest DEPS_CMAKE_FLAGS=-DUSE_BUNDLED_GPERF=OFF; fi; \
 	if ${TEST_09}; then $(MAKE) -C ${NVIM_0.9_PATH} functionaltest; fi; \