build: add Makefile with test, lint, lint-fix, coverage targets

Author: dndungu

Makefile

@@ -0,0 +1,68 @@
+SHELL := /bin/sh
+
+PKG := ./...
+COVER_DIR := coverage
+COVER_PROFILE := $(COVER_DIR)/coverage.out
+COVER_HTML := $(COVER_DIR)/coverage.html
+
+.PHONY: all test race vet fmt fmt-check lint lint-fix cover cover-html ci
+
+all: test
+
+# Run unit tests
+test:
+	go test $(PKG)
+
+# Run tests with race detector
+race:
+	go test -race $(PKG)
+
+# Static analysis
+vet:
+	go vet $(PKG)
+
+# Auto-format code
+fmt:
+	gofmt -s -w .
+
+# Check formatting without modifying files; fails if formatting needed
+fmt-check:
+	@diff=$$(gofmt -s -l .); \
+	if [ -n "$$diff" ]; then \
+		echo "Files need formatting:"; echo "$$diff"; exit 1; \
+	else \
+		echo "Formatting OK"; \
+	fi
+
+# Lint: go vet + formatting check + optional golangci-lint if installed
+lint:
+	@echo "Running go vet"; go vet $(PKG)
+	@echo "Checking formatting"; \
+	diff=$$(gofmt -s -l .); if [ -n "$$diff" ]; then echo "Files need formatting:"; echo "$$diff"; exit 1; else echo "Formatting OK"; fi
+	@if command -v golangci-lint >/dev/null 2>&1; then \
+		echo "Running golangci-lint"; golangci-lint run; \
+	else \
+		echo "golangci-lint not installed; skipping"; \
+	fi
+
+# Attempt to fix lint: gofmt + optional golangci-lint --fix if installed
+lint-fix: fmt
+	@if command -v golangci-lint >/dev/null 2>&1; then \
+		echo "Running golangci-lint --fix"; golangci-lint run --fix || true; \
+	else \
+		echo "golangci-lint not installed; skipping"; \
+	fi
+
+# Generate coverage profile and print total coverage
+cover:
+	mkdir -p $(COVER_DIR)
+	go test -covermode=atomic -coverprofile=$(COVER_PROFILE) $(PKG)
+	go tool cover -func=$(COVER_PROFILE) | tail -n 1
+
+# Generate HTML coverage report
+cover-html: cover
+	go tool cover -html=$(COVER_PROFILE) -o $(COVER_HTML)
+	@echo "Wrote $(COVER_HTML)"
+
+# CI-style aggregate target
+ci: fmt-check vet test cover