t/Makefile: add machinery to check correctness of chainlint.sed

The --chain-lint option uses heuristics and knowledge of shell syntax to
detect broken &&-chains in subshells by pure textual inspection.
Although the heuristics work well, they are still best-guesses and
future changes could accidentally break assumptions upon which they are
based. To protect against this possibility, tests checking correctness
of the linter itself will be added. As preparation, add a new makefile
"check-chainlint" target and associated machinery.

Signed-off-by: Eric Sunshine <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

t/.gitignore

@@ -1,3 +1,4 @@
 /trash directory*
 /test-results
 /.prove
+/chainlinttmp

t/Makefile

@@ -18,23 +18,28 @@ TEST_LINT ?= test-lint
 
 ifdef TEST_OUTPUT_DIRECTORY
 TEST_RESULTS_DIRECTORY = $(TEST_OUTPUT_DIRECTORY)/test-results
+CHAINLINTTMP = $(TEST_OUTPUT_DIRECTORY)/chainlinttmp
 else
 TEST_RESULTS_DIRECTORY = test-results
+CHAINLINTTMP = chainlinttmp
 endif
 
 # Shell quote;
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 TEST_SHELL_PATH_SQ = $(subst ','\'',$(TEST_SHELL_PATH))
 PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
 TEST_RESULTS_DIRECTORY_SQ = $(subst ','\'',$(TEST_RESULTS_DIRECTORY))
+CHAINLINTTMP_SQ = $(subst ','\'',$(CHAINLINTTMP))
 
 T = $(sort $(wildcard t[0-9][0-9][0-9][0-9]-*.sh))
 TGITWEB = $(sort $(wildcard t95[0-9][0-9]-*.sh))
 THELPERS = $(sort $(filter-out $(T),$(wildcard *.sh)))
+CHAINLINTTESTS = $(sort $(patsubst chainlint/%.test,%,$(wildcard chainlint/*.test)))
+CHAINLINT = sed -f chainlint.sed
 
 all: $(DEFAULT_TEST_TARGET)
 
-test: pre-clean $(TEST_LINT)
+test: pre-clean check-chainlint $(TEST_LINT)
 	$(MAKE) aggregate-results-and-cleanup
 
 failed:
@@ -43,7 +48,7 @@ failed:
 		sed -n 's/\.counts$$/.sh/p') && \
 	test -z "$$failed" || $(MAKE) $$failed
 
-prove: pre-clean $(TEST_LINT)
+prove: pre-clean check-chainlint $(TEST_LINT)
 	@echo "*** prove ***"; $(PROVE) --exec '$(TEST_SHELL_PATH_SQ)' $(GIT_PROVE_OPTS) $(T) :: $(GIT_TEST_OPTS)
 	$(MAKE) clean-except-prove-cache
 
@@ -53,13 +58,25 @@ $(T):
 pre-clean:
 	$(RM) -r '$(TEST_RESULTS_DIRECTORY_SQ)'
 
-clean-except-prove-cache:
+clean-except-prove-cache: clean-chainlint
 	$(RM) -r 'trash directory'.* '$(TEST_RESULTS_DIRECTORY_SQ)'
 	$(RM) -r valgrind/bin
 
 clean: clean-except-prove-cache
 	$(RM) .prove
 
+clean-chainlint:
+	$(RM) -r '$(CHAINLINTTMP_SQ)'
+
+check-chainlint:
+	@mkdir -p '$(CHAINLINTTMP_SQ)' && \
+	err=0 && \
+	for i in $(CHAINLINTTESTS); do \
+		$(CHAINLINT) <chainlint/$$i.test | \
+		sed -e '/^# LINT: /d' >'$(CHAINLINTTMP_SQ)'/$$i.actual && \
+		diff -u chainlint/$$i.expect '$(CHAINLINTTMP_SQ)'/$$i.actual || err=1; \
+	done && exit $$err
+
 test-lint: test-lint-duplicates test-lint-executable test-lint-shell-syntax \
 	test-lint-filenames
 
@@ -102,4 +119,4 @@ valgrind:
 perf:
 	$(MAKE) -C perf/ all
 
-.PHONY: pre-clean $(T) aggregate-results clean valgrind perf
+.PHONY: pre-clean $(T) aggregate-results clean valgrind perf check-chainlint clean-chainlint