Integrate GolangCI-Lint (#90)

* Use plugin orb for ci

* Add golangci-lint config and fix issues

* Simplify circleci config

* Drop unparam

* Drop maligned

* Ignore varcheck in server/manifest.go

.circleci/config.yml

@@ -1,27 +1,12 @@
 version: 2.1
-executors:
-  default:
-    docker:
-      - image: circleci/golang:1.14-node
 
-jobs:
-  lint:
-    executor:
-      name: default
-    steps:
-      - checkout
-      - run: make check-style
-
-  test:
-    executor:
-      name: default
-    steps:
-      - checkout
-      - run: make test
+orbs:
+  plugin-ci: mattermost/plugin-ci@0.1.0
 
 workflows:
   version: 2
-  untagged-build:
+  ci:
     jobs:
-      - lint
-      - test
+      - plugin-ci/lint
+      - plugin-ci/test
+      - plugin-ci/build

.golangci.yml

@@ -0,0 +1,60 @@
+run:
+  timeout: 5m
+  modules-download-mode: readonly
+
+linters-settings:
+  goconst:
+    min-len: 2
+    min-occurrences: 2
+  gofmt:
+    simplify: true
+  goimports:
+    local-prefixes: github.com/mattermost/mattermost-starter-template
+  golint:
+    min-confidence: 0
+  govet:
+    check-shadowing: true
+    enable-all: true
+  misspell:
+    locale: US
+
+linters:
+  disable-all: true
+  enable:
+    - bodyclose
+    - deadcode
+    - errcheck
+    - goconst
+    - gocritic
+    - gofmt
+    - goimports
+    - golint
+    - gosec
+    - gosimple
+    - govet
+    - ineffassign
+    - interfacer
+    - misspell
+    - nakedret
+    - staticcheck
+    - structcheck
+    - stylecheck
+    - typecheck
+    - unconvert
+    - unused
+    - varcheck
+    - whitespace
+
+issues:
+  exclude-rules:
+    - path: server/manifest.go
+      linters:
+        - unused
+        - varcheck
+    - path: server/configuration.go
+      linters:
+        - unused
+    - path: _test\.go
+      linters:
+        - goconst
+        - scopelint # https://github.com/kyoh86/scopelint/issues/4

Makefile

@@ -30,54 +30,25 @@ all: check-style test dist
 apply:
 	./build/bin/manifest apply
 
-## Runs govet and gofmt against all packages.
+## Runs golangci-lint and eslint.
 .PHONY: check-style
-check-style: webapp/.npminstall gofmt govet golint
+check-style: webapp/.npminstall golangci-lint
 	@echo Checking for style guide compliance
 
 ifneq ($(HAS_WEBAPP),)
 	cd webapp && npm run lint
 endif
 
-## Runs gofmt against all packages.
-.PHONY: gofmt
-gofmt:
-ifneq ($(HAS_SERVER),)
-	@echo Running gofmt
-	@for package in $$(go list ./...); do \
-		echo "Checking "$$package; \
-		files=$$(go list -f '{{range .GoFiles}}{{$$.Dir}}/{{.}} {{end}}' $$package); \
-		if [ "$$files" ]; then \
-			gofmt_output=$$(gofmt -d -s $$files 2>&1); \
-			if [ "$$gofmt_output" ]; then \
-				echo "$$gofmt_output"; \
-				echo "Gofmt failure"; \
-				exit 1; \
-			fi; \
-		fi; \
-	done
-	@echo Gofmt success
-endif
+## Run golangci-lint on codebase.
+.PHONY: golangci-lint
+golangci-lint:
+	@if ! [ -x "$$(command -v golangci-lint)" ]; then \
+		echo "golangci-lint is not installed. Please see https://github.com/golangci/golangci-lint#install for installation instructions."; \
+		exit 1; \
+	fi; \
 
-## Runs govet against all packages.
-.PHONY: govet
-govet:
-ifneq ($(HAS_SERVER),)
-	@echo Running govet
-	@# Workaround because you can't install binaries without adding them to go.mod
-	env GO111MODULE=off $(GO) get golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow
-	$(GO) vet ./...
-	$(GO) vet -vettool=$(GOPATH)/bin/shadow ./...
-	@echo Govet success
-endif
-
-## Runs golint against all packages.
-.PHONY: golint
-golint:
-	@echo Running lint
-	env GO111MODULE=off $(GO) get golang.org/x/lint/golint
-	$(GOPATH)/bin/golint -set_exit_status ./...
-	@echo lint success
+	@echo Running golangci-lint
+	golangci-lint run ./...
 
 ## Builds the server, if it exists, including support for multiple architectures.
 .PHONY: server
@@ -104,6 +75,7 @@ ifneq ($(HAS_WEBAPP),)
 endif
 
 ## Builds the webapp in debug mode, if it exists.
+.PHONY: webapp-debug
 webapp-debug: webapp/.npminstall
 ifneq ($(HAS_WEBAPP),)
 	cd webapp && \

build/deploy/main.go

@@ -85,13 +85,13 @@ func uploadPlugin(client *model.Client4, pluginID, bundlePath string) error {
 	log.Print("Uploading plugin via API.")
 	_, resp := client.UploadPluginForced(pluginBundle)
 	if resp.Error != nil {
-		return fmt.Errorf("Failed to upload plugin bundle: %s", resp.Error.Error())
+		return errors.Wrap(resp.Error, "failed to upload plugin bundle")
 	}
 
 	log.Print("Enabling plugin.")
 	_, resp = client.EnablePlugin(pluginID)
 	if resp.Error != nil {
-		return fmt.Errorf("Failed to enable plugin: %s", resp.Error.Error())
+		return errors.Wrap(resp.Error, "Failed to enable plugin")
 	}
 
 	return nil

server/plugin_test.go

@@ -19,6 +19,7 @@ func TestServeHTTP(t *testing.T) {
 
 	result := w.Result()
 	assert.NotNil(result)
+	defer result.Body.Close()
 	bodyBytes, err := ioutil.ReadAll(result.Body)
 	assert.Nil(err)
 	bodyString := string(bodyBytes)