t/Makefile: optimize chainlint self-test

sunshineco · gitster · commit f30c1d5eb1ce · 2021-12-13T14:15:28.000-08:00
Rather than running `chainlint` and `diff` once per self-test -- which
may become expensive as more tests are added -- instead run `chainlint`
a single time over all tests bodies collectively and compare the result
to the collective "expected" output.

Signed-off-by: Eric Sunshine &lt;sunshine@sunshineco.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/t/Makefile b/t/Makefile
@@ -71,12 +71,10 @@ clean-chainlint:
 
 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
+	sed -e '/^# LINT: /d' $(patsubst %,chainlint/%.test,$(CHAINLINTTESTS)) >'$(CHAINLINTTMP_SQ)'/tests && \
+	cat $(patsubst %,chainlint/%.expect,$(CHAINLINTTESTS)) >'$(CHAINLINTTMP_SQ)'/expect && \
+	$(CHAINLINT) '$(CHAINLINTTMP_SQ)'/tests >'$(CHAINLINTTMP_SQ)'/actual && \
+	diff -u '$(CHAINLINTTMP_SQ)'/expect '$(CHAINLINTTMP_SQ)'/actual
 
 test-lint: test-lint-duplicates test-lint-executable test-lint-shell-syntax \
 	test-lint-filenames
