[hw-2] add tests, coverage, benchmarks

make/coverage.mk

@@ -0,0 +1,28 @@
+COV_REPORT_DIR := .coverage
+
+define coverage
+	@if [ -f "$(1)/go.mod" ]; then \
+		echo "===== coverage for $(1) ====="; \
+		outdir=$(COV_REPORT_DIR)/$(1); \
+		mkdir -p $$outdir; \
+		pkgs=$$(go list ./$(1)/... | grep -vE 'mock|config|generated|header|document|internal/pb'); \
+		if [ -z "$$pkgs" ]; then \
+			echo "no packages to test in $(1)"; exit 0; \
+		fi; \
+		go test -race -covermode=atomic -coverprofile=$$outdir/coverage.out $$pkgs; \
+		go tool cover -html=$$outdir/coverage.out -o $$outdir/coverage.html; \
+		echo "html report: $$outdir/coverage.html"; \
+	fi
+endef
+
+cart-coverage:
+	$(call coverage,cart)
+
+loms-coverage:
+	$(call coverage,loms)
+
+notifier-coverage:
+	$(call coverage,notifier)
+
+comments-coverage:
+	$(call coverage,comments)