+ $(ECHO) " multifile ## Test multiple file arguments"
+ @(echo "inven" | advent isofoo.log /dev/stdin | diff --text -u multifile.chk -) || exit 1
+ rm -f scratch.tmp /tmp/regress$$$$
+
+# Steps towards TAP. savecheck and the isofoo test are not yet integrated.
+
+# The TAP filter. Only affects presentation of the test suite messages
+TAPCONSUMER=tapview
+
+# Fall back to safety if our declared TAP consumer does not exist.
+# This is helpful in the CI environment, where it would be better for
+# the logfiles to carry the raw TAP messages.
+TAPFILTER=$(shell command -v $(TAPCONSUMER) || echo cat)
+
+# Parallel make doesn't return a fail status when a single subprocess fails,
+# so we need to log the failures and check the log for nonemptiness in order
+# to hand a real status back. This is important for CI/CD.
+FAILLOG=/tmp/advent-test.log
+
+TEST_TARGETS=$(TESTLOADS:%=run-regress-%)
+$(TEST_TARGETS): run-regress-%: %.log
+ @(test=$(<:.log=); legend=$$(sed -n '/^## /s///p' <"$<" 2>/dev/null || echo "(no description)"); \
+ OPTS=`sed -n /#options:/s///p $<`; \
+ $(advent) $$OPTS <$< | tapdiffer "$<: $${legend}" "$${test}.chk") >>$(FAILLOG)
+
+tap: count $(TEST_TARGETS)
+count:
+ @echo 1..$(words $(TEST_TARGETS)) >$(FAILLOG)
+
+tapcheck:
+ @make --no-print-directory tap; tapview <$(FAILLOG)