Add linting to CircleCI & to the Makefile.

.circleci/config.yml

@@ -31,6 +31,22 @@ jobs:
       - store_test_results:
           path: /tmp/test-results
 
+  lint:
+    docker:
+      - image: circleci/golang:1.13-node
+
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+            - go-mod-{{ checksum "go.sum" }}
+      - run:
+          name: Install golint
+          command: go get golang.org/x/lint/golint
+      - run:
+          name: Lint & check
+          command: make check
+
   acceptance:
     docker:
       - image: circleci/golang:1.13-node
@@ -110,6 +126,7 @@ workflows:
   build:
     jobs:
       - test
+      - lint
       - acceptance
       - buildimage
       - release_docker:

Makefile

@@ -27,6 +27,17 @@ conftest:
 test: conftest
 	$(BUILD) --target test .
 
+check: check-fmt check-vet check-lint
+
+check-fmt:
+	test -z $$(gofmt -l .) || echo $$(gofmt -l .)
+
+check-vet:
+	go vet ./...
+
+check-lint:
+	golint -set_exit_status ./...
+
 push: examples conftest
 	$(PUSH) $(IMAGE):$(TAG)
 	$(PUSH) $(IMAGE):latest

internal/runner/test.go

@@ -13,6 +13,8 @@ import (
 	"github.com/open-policy-agent/conftest/policy"
 )
 
+// TestRunner is the runner for the Test command, executing
+// Rego policy checks against configuration files.
 type TestRunner struct {
 	Trace         bool
 	Policy        []string

internal/runner/verify.go

@@ -12,6 +12,8 @@ import (
 	"github.com/open-policy-agent/opa/topdown"
 )
 
+// VerifyRunner is the runner for the Verify command, executing
+// Rego policy unit-tests.
 type VerifyRunner struct {
 	Policy  []string
 	Data    []string

policy/engine.go

@@ -61,7 +61,7 @@ func Load(ctx context.Context, policyPaths []string) (*Engine, error) {
 	return &engine, nil
 }
 
-// Load returns an Engine after loading all of the specified policies and data paths.
+// LoadWithData returns an Engine after loading all of the specified policies and data paths.
 func LoadWithData(ctx context.Context, policyPaths []string, dataPaths []string) (*Engine, error) {
 	engine, err := Load(ctx, policyPaths)
 	if err != nil {