chore: setup golangci-lint for precommit check & add go mod tidy chec…

…k to github actions

.github/workflows/go.yml

@@ -20,3 +20,5 @@ jobs:
         run: go build -v ./...
       - name: Test
         run: go test -v ./...
+      - name: Mod Tidy
+        run: go mod tidy && git diff --exit-code -- go.mod go.sum || (echo "go modules are not tidy, run 'go mod tidy'." && exit 1)

.github/workflows/golangci-lint.yml

@@ -12,4 +12,6 @@ jobs:
         uses: golangci/golangci-lint-action@v2
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
+          # NOTICE: golangci-lint version should be the same as go.mod. When upgrading, also update go.mod by:
+          # go get github.com/golangci/[email protected]
           version: v1.29

Makefile

@@ -12,16 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-precommit: FORCE tidy lint csv
-
-csv: FORCE
-	go run . csv github.com/google/go-licenses
-
-lint: FORCE
-# There's no need to lint third_party packages, so we explicitly list other packages here.
-	golint --set_exit_status . licenses/...
+precommit: tidy lint
 
 tidy: FORCE
 	go mod tidy
 
+lint:  FORCE
+# Note, golangci-lint version is pinned in go.mod. When upgrading, also
+# upgrade version in .github/workflows/golangci-lint.yml.
+	go run github.com/golangci/golangci-lint/cmd/golangci-lint run -v
+
 FORCE: ;

go.mod

@@ -4,6 +4,7 @@ go 1.16
 
 require (
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
+	github.com/golangci/golangci-lint v1.29.0
 	github.com/google/go-cmp v0.5.6
 	github.com/google/licenseclassifier v0.0.0-20210722185704-3043a050f148
 	github.com/otiai10/copy v1.6.0