Makefile

# Run an arbitrary Emacs version like
#   make test emacs="docker run --rm -it -v $PWD:/work -w /work silex/emacs:26 emacs"
emacs := emacs
dependencies := flycheck reformatter
run_emacs = $(emacs) -Q -L . -L $(elpa_dir) -l package \
	--eval "(setq package-user-dir (expand-file-name \"$(elpa_dir)\"))" \
	--eval "(add-to-list 'package-archives '(\"melpa\" . \"https://melpa.org/packages/\") t)" \
	--eval "(package-initialize)"
elpa_dir := elpa

.PHONY: test
test: ## Compile and run unit tests
test: test-compile

$(elpa_dir):
	$(run_emacs) \
		--eval "(unless (seq-every-p (lambda (e) (require e nil t)) '($(dependencies))) \
			(package-refresh-contents) (mapc #'package-install '($(dependencies))))" \
		--batch

.PHONY: deps
deps: $(elpa_dir)

.PHONY: test-compile
test-compile: | $(elpa_dir)
	$(run_emacs) \
		--eval '(setq byte-compile-error-on-warn t)' \
		--batch -f batch-byte-compile *.el

.PHONY: clean
clean: ## Clean files
	rm -f *.elc

.PHONY: clobber
clobber: ## Remove all generated files
clobber: clean
	rm -rf $(elpa_dir)

# Hooks

hooks := $(filter-out %~,$(wildcard hooks/*))
git_dir := $(shell git rev-parse --git-dir)

.PHONY: hooks
hooks: ## Install helpful git hooks
hooks: $(foreach _,$(hooks),$(git_dir)/hooks/$(notdir $(_)))

$(git_dir)/hooks/%: hooks/%
	ln -s $(PWD)/$(<) $(@)

.PHONY: help
help: ## Show this help text
	$(info usage: make [target])
	$(info )
	$(info Available targets:)
	@awk -F ':.*?## *' '/^[^\t].+?:.*?##/ \
         {printf "  %-24s %s\n", $$1, $$2}' $(MAKEFILE_LIST)