Codestyle: Add typecheck and unused linters (#17491)

Signed-off-by: Mario Trangoni <mjtrangoni@gmail.com>

scripts/backend-lint.sh

@@ -31,7 +31,9 @@ exit_if_fail golangci-lint run --deadline 10m --disable-all \
   --enable=govet\
   --enable=ineffassign\
   --enable=structcheck\
+  --enable=typecheck\
   --enable=unconvert\
+  --enable=unused\
   --enable=varcheck
 
 exit_if_fail go vet ./pkg/...

scripts/build/publish_test.go

-package main
-
-import (
-	"testing"
-)
-
-type testPackage struct {
-	path    string
-	version string
-	os      string
-	arch    string
-}
-
-var testData = []testPackage{
-	{
-		path:    "grafana-5.2.0-474pre1.aarch64.rpm",
-		version: "5.2.0-474pre1",
-		os:      "rhel",
-		arch:    "arm64",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.armhfp.rpm",
-		version: "5.2.0-474pre1",
-		os:      "rhel",
-		arch:    "armv7",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.darwin-amd64.tar.gz",
-		version: "5.2.0-474pre1",
-		os:      "darwin",
-		arch:    "amd64",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.linux-amd64.tar.gz",
-		version: "5.2.0-474pre1",
-		os:      "linux",
-		arch:    "amd64",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.linux-arm64.tar.gz",
-		version: "5.2.0-474pre1",
-		os:      "linux",
-		arch:    "arm64",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.linux-armv7.tar.gz",
-		version: "5.2.0-474pre1",
-		os:      "linux",
-		arch:    "armv7",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.windows-amd64.zip",
-		version: "5.2.0-474pre1",
-		os:      "win",
-		arch:    "amd64",
-	},
-	{
-		path:    "grafana-5.2.0-474pre1.x86_64.rpm",
-		version: "5.2.0-474pre1",
-		os:      "rhel",
-		arch:    "amd64",
-	},
-	{
-		path:    "grafana_5.2.0-474pre1_amd64.deb",
-		version: "5.2.0-474pre1",
-		os:      "deb",
-		arch:    "amd64",
-	},
-	{
-		path:    "grafana_5.2.0-474pre1_arm64.deb",
-		version: "5.2.0-474pre1",
-		os:      "deb",
-		arch:    "arm64",
-	},
-	{
-		path:    "grafana_5.2.0-474pre1_armhf.deb",
-		version: "5.2.0-474pre1",
-		os:      "deb",
-		arch:    "armv7",
-	},
-}
-
-func TestFileWalker(t *testing.T) {
-	for _, packageInfo := range testData {
-		version = ""
-		actualPackageInfo, err := mapPackage(packageInfo.path, packageInfo.path, []byte{})
-		if err != nil {
-			t.Error(err)
-			continue
-		}
-
-		if version != packageInfo.version {
-			t.Errorf("Testing (%v), expected %v to be %v.", packageInfo.path, version, packageInfo.version)
-		}
-
-		if actualPackageInfo.Os != packageInfo.os {
-			t.Errorf("Testing (%v), expected %v to be %v.", packageInfo.path, actualPackageInfo.Os, packageInfo.os)
-		}
-
-		if actualPackageInfo.Arch != packageInfo.arch {
-			t.Errorf("Testing (%v), expected %v to be %v.", packageInfo.path, actualPackageInfo.Arch, packageInfo.arch)
-		}
-	}
-
-	incorrectPackageName := "grafana_5.2.0-474pre1_armfoo.deb"
-	_, err := mapPackage(incorrectPackageName, incorrectPackageName, []byte{})
-	if err == nil {
-		t.Errorf("Testing (%v), expected to fail due to an unrecognized arch, but signaled no error.", incorrectPackageName)
-	}
-}