From 58459d5a90964a8d08ff7f79b259fdbe6e59fdf4 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 17:54:16 +0300
Subject: [PATCH 01/12] linters

---
 linters/.golangci.yml            | 117 +++++++++++++++++++++++++++++++
 linters/Makefile                 |   8 +++
 linters/errs/common.go           |  13 ++++
 linters/errs/errcheck.go         |   5 ++
 linters/errs/ineffassign.go      |  11 +++
 linters/errs/ineffassign_test.go |  12 ++++
 linters/errs/staticcheck.go      |   7 ++
 linters/errs/staticcheck_test.go |  12 ++++
 linters/go.mod                   |  11 +++
 linters/go.sum                   |  15 ++++
 10 files changed, 211 insertions(+)
 create mode 100644 linters/.golangci.yml
 create mode 100644 linters/Makefile
 create mode 100644 linters/errs/common.go
 create mode 100644 linters/errs/errcheck.go
 create mode 100644 linters/errs/ineffassign.go
 create mode 100644 linters/errs/ineffassign_test.go
 create mode 100644 linters/errs/staticcheck.go
 create mode 100644 linters/errs/staticcheck_test.go
 create mode 100644 linters/go.mod
 create mode 100644 linters/go.sum

diff --git a/linters/.golangci.yml b/linters/.golangci.yml
new file mode 100644
index 0000000..b022732
--- /dev/null
+++ b/linters/.golangci.yml
@@ -0,0 +1,117 @@
+linters:
+  # Please, do not use `enable-all`: it's deprecated and will be removed soon.
+  # Inverted configuration with `enable-all` and `disable` is not scalable during updates of golangci-lint.
+  # Full list of linters - https://golangci-lint.run/usage/linters
+  disable-all: true
+  enable:
+    - bodyclose # https://github.com/timakin/bodyclose
+#    - deadcode
+    - depguard
+    - errcheck # Mandatory. Do not disable.
+    - gocritic
+    - goimports
+    - gosec
+    - gosimple
+    - govet
+    - noctx
+    - nolintlint
+    - ineffassign # Mandatory. Do not disable.
+    - staticcheck # Mandatory. Do not disable.
+    - stylecheck
+    - structcheck
+    - typecheck
+#    - unused
+    - varcheck
+
+# Other linters:
+#    - dogsled
+#    - dupl
+#    - exportloopref
+#    - exhaustive # e.g. missing cases in switch of type
+#    - funlen
+#    - gochecknoinits
+#    - gocognit
+#    - goconst
+#    - gocyclo
+#    - goerr113
+#    - gofmt
+#    - goprintffuncname
+#    - lll
+#    - misspell
+#    - nakedret
+#    - nlreturn
+#    - prealloc
+#    - revive
+#    - rowserrcheck
+#    - stylecheck
+#    - unconvert
+#    - unparam
+
+linters-settings:
+  gocritic:
+    enabled-tags:
+      - diagnostic
+      - experimental
+      - opinionated
+      - performance
+      - style
+    disabled-checks:
+      - commentedOutCode
+      - dupImport # https://github.com/go-critic/go-critic/issues/845
+      - octalLiteral
+      - wrapperFunc
+      - whyNoLint
+      - hugeParam # TODO: configure(80 bytes is probably not so much) and enable.
+
+  errcheck:
+    # List of functions to exclude from checking, where each entry is a single function to exclude.
+    # See https://github.com/kisielk/errcheck#excluding-functions for details.
+    exclude-functions:
+      - (io.Closer).Close
+      - (io.ReadCloser).Close
+
+  govet:
+    enable-all: true
+    disable:
+     - shadow
+     - fieldalignment
+
+  depguard:
+    # Kind of list is passed in.
+    # Allowed values: allowlist|denylist
+    # Default: denylist
+    list-type: denylist
+    # Check the list against standard lib.
+    # Default: false
+    include-go-root: true
+    # A list of packages for the list type specified.
+    # Default: []
+    packages:
+      - github.com/pkg/errors
+    # A list of packages for the list type specified.
+    # Specify an error message to output when a denied package is used.
+    # Default: []
+    packages-with-error-message:
+      - github.com/pkg/errors: 'Deprecated: use standard "errors" instead.'
+
+  stylecheck:
+    # Select the Go version to target.
+    # Default: 1.13
+    go: "1.17"
+    # https://staticcheck.io/docs/options#checks
+    checks: ["all"]
+
+issues:
+  # Maximum issues count per one linter. Set to 0 to disable. Default is 50.
+  max-issues-per-linter: 0
+
+  # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
+  max-same-issues: 50
+
+run:
+  # include test files or not, default is true
+  tests: true
+
+  # Timeout for analysis, e.g. 30s, 5m.
+  # Default: 1m
+  timeout: 5m
diff --git a/linters/Makefile b/linters/Makefile
new file mode 100644
index 0000000..e126847
--- /dev/null
+++ b/linters/Makefile
@@ -0,0 +1,8 @@
+# linter:
+GOLINT = $(GOPATH)/bin/golangci-lint
+$(GOLINT):
+	curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin v1.48.0
+
+.PHONY: lint
+lint: $(GOLINT)
+	$(GOLINT) run
diff --git a/linters/errs/common.go b/linters/errs/common.go
new file mode 100644
index 0000000..c893b09
--- /dev/null
+++ b/linters/errs/common.go
@@ -0,0 +1,13 @@
+package errs
+
+import (
+	"errors"
+)
+
+func fnWithError() error {
+	return errors.New("some error")
+}
+
+func fnNoError() error {
+	return nil
+}
diff --git a/linters/errs/errcheck.go b/linters/errs/errcheck.go
new file mode 100644
index 0000000..619c3b1
--- /dev/null
+++ b/linters/errs/errcheck.go
@@ -0,0 +1,5 @@
+package errs
+
+func errcheck() {
+	fnWithError()
+}
diff --git a/linters/errs/ineffassign.go b/linters/errs/ineffassign.go
new file mode 100644
index 0000000..701c6f0
--- /dev/null
+++ b/linters/errs/ineffassign.go
@@ -0,0 +1,11 @@
+package errs
+
+func ineffassign() error {
+	err := fnWithError()
+	err = fnNoError()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/linters/errs/ineffassign_test.go b/linters/errs/ineffassign_test.go
new file mode 100644
index 0000000..136cc46
--- /dev/null
+++ b/linters/errs/ineffassign_test.go
@@ -0,0 +1,12 @@
+package errs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ineffassign(t *testing.T) {
+	err := ineffassign()
+	require.Error(t, err)
+}
diff --git a/linters/errs/staticcheck.go b/linters/errs/staticcheck.go
new file mode 100644
index 0000000..c0e7e8d
--- /dev/null
+++ b/linters/errs/staticcheck.go
@@ -0,0 +1,7 @@
+package errs
+
+func staticcheck() (err error) {
+	err = fnWithError()
+	err = fnNoError()
+	return
+}
diff --git a/linters/errs/staticcheck_test.go b/linters/errs/staticcheck_test.go
new file mode 100644
index 0000000..e0f8ab5
--- /dev/null
+++ b/linters/errs/staticcheck_test.go
@@ -0,0 +1,12 @@
+package errs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_staticcheck(t *testing.T) {
+	err := staticcheck()
+	require.Error(t, err)
+}
diff --git a/linters/go.mod b/linters/go.mod
new file mode 100644
index 0000000..e563be7
--- /dev/null
+++ b/linters/go.mod
@@ -0,0 +1,11 @@
+module linters
+
+go 1.17
+
+require github.com/stretchr/testify v1.8.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/linters/go.sum b/linters/go.sum
new file mode 100644
index 0000000..5164829
--- /dev/null
+++ b/linters/go.sum
@@ -0,0 +1,15 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

From 3e2079ebb40f88e74a4cab582be16712f63b8d34 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 17:58:01 +0300
Subject: [PATCH 02/12] added config

---
 .github/workflows/lint.yaml | 44 +++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 .github/workflows/lint.yaml

diff --git a/.github/workflows/lint.yaml b/.github/workflows/lint.yaml
new file mode 100644
index 0000000..a34ee44
--- /dev/null
+++ b/.github/workflows/lint.yaml
@@ -0,0 +1,44 @@
+name: Lint
+
+on:
+  push:
+    branches:
+      - master
+      - main
+  pull_request:
+
+jobs:
+  lint:
+    name: lint
+    strategy:
+      matrix:
+        os: [ ubuntu-latest ]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          go-version-file: ./go.mod
+
+      - name: Cache/restore build and pkg cache
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          version: v1.48
+
+          skip-cache: true
+
+          # Optional: working directory, useful for monorepos
+          working-directory: linters

From 0f815db5ee1d1ef1788e66c5fda042fc132de69d Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 17:59:05 +0300
Subject: [PATCH 03/12] enabled

---
 linters/.golangci.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/linters/.golangci.yml b/linters/.golangci.yml
index b022732..6f74f44 100644
--- a/linters/.golangci.yml
+++ b/linters/.golangci.yml
@@ -5,7 +5,7 @@ linters:
   disable-all: true
   enable:
     - bodyclose # https://github.com/timakin/bodyclose
-#    - deadcode
+    - deadcode
     - depguard
     - errcheck # Mandatory. Do not disable.
     - gocritic
@@ -20,7 +20,7 @@ linters:
     - stylecheck
     - structcheck
     - typecheck
-#    - unused
+    - unused
     - varcheck
 
 # Other linters:

From 281c162d3ec798fb6c7bed768635074b05982edc Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 18:00:07 +0300
Subject: [PATCH 04/12] fix

---
 .github/workflows/lint.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/lint.yaml b/.github/workflows/lint.yaml
index a34ee44..8661fd8 100644
--- a/.github/workflows/lint.yaml
+++ b/.github/workflows/lint.yaml
@@ -21,7 +21,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v3
         with:
-          go-version-file: ./go.mod
+          go-version-file: ./linters/go.mod
 
       - name: Cache/restore build and pkg cache
         uses: actions/cache@v3

From 71f1266f8729b6203f9e950421cc3c70f736504d Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 18:03:09 +0300
Subject: [PATCH 05/12] revert

---
 linters/.golangci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/linters/.golangci.yml b/linters/.golangci.yml
index 6f74f44..1216e12 100644
--- a/linters/.golangci.yml
+++ b/linters/.golangci.yml
@@ -5,7 +5,7 @@ linters:
   disable-all: true
   enable:
     - bodyclose # https://github.com/timakin/bodyclose
-    - deadcode
+#    - deadcode
     - depguard
     - errcheck # Mandatory. Do not disable.
     - gocritic

From b62c4d0785621498ae15450684afa7fed773abd2 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 18:04:03 +0300
Subject: [PATCH 06/12] errcheck

---
 linters/errs/errcheck.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/linters/errs/errcheck.go b/linters/errs/errcheck.go
index 619c3b1..11016f8 100644
--- a/linters/errs/errcheck.go
+++ b/linters/errs/errcheck.go
@@ -1,5 +1,7 @@
 package errs
 
-func errcheck() {
+func errcheck() error {
 	fnWithError()
+
+	return nil
 }

From 5a0d83f4f8845a9021f3e644d2c529151234fa2b Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Tue, 16 Aug 2022 18:04:19 +0300
Subject: [PATCH 07/12] revert

---
 linters/.golangci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/linters/.golangci.yml b/linters/.golangci.yml
index 1216e12..b022732 100644
--- a/linters/.golangci.yml
+++ b/linters/.golangci.yml
@@ -20,7 +20,7 @@ linters:
     - stylecheck
     - structcheck
     - typecheck
-    - unused
+#    - unused
     - varcheck
 
 # Other linters:

From 692d9fdef8ef98fd5d61e007f1c7523d55077658 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Fri, 26 Aug 2022 13:38:54 +0300
Subject: [PATCH 08/12] removed deprecated

---
 linters/.golangci.yml | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/linters/.golangci.yml b/linters/.golangci.yml
index b022732..bf7c99a 100644
--- a/linters/.golangci.yml
+++ b/linters/.golangci.yml
@@ -5,7 +5,6 @@ linters:
   disable-all: true
   enable:
     - bodyclose # https://github.com/timakin/bodyclose
-#    - deadcode
     - depguard
     - errcheck # Mandatory. Do not disable.
     - gocritic
@@ -18,10 +17,8 @@ linters:
     - ineffassign # Mandatory. Do not disable.
     - staticcheck # Mandatory. Do not disable.
     - stylecheck
-    - structcheck
     - typecheck
 #    - unused
-    - varcheck
 
 # Other linters:
 #    - dogsled

From 1acab899eb35cd7aa81f21a5f6991eb9a5865028 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Fri, 26 Aug 2022 14:51:05 +0300
Subject: [PATCH 09/12] ineffassign

---
 linters/ineffassign/ineffassign.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 linters/ineffassign/ineffassign.go

diff --git a/linters/ineffassign/ineffassign.go b/linters/ineffassign/ineffassign.go
new file mode 100644
index 0000000..1d23d23
--- /dev/null
+++ b/linters/ineffassign/ineffassign.go
@@ -0,0 +1,17 @@
+package ineffassign
+
+func storeCounter(counter int) {
+	_ = counter
+}
+
+func ineffassign() {
+	var counter int
+
+	// do something
+
+	counter++
+	storeCounter(counter)
+
+	// do something else
+	counter++
+}

From a3f63dbd34e83a5f0a5d431f59a9a63ce22100ab Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Fri, 26 Aug 2022 14:52:38 +0300
Subject: [PATCH 10/12] better naming

---
 linters/ineffassign/ineffassign.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/linters/ineffassign/ineffassign.go b/linters/ineffassign/ineffassign.go
index 1d23d23..e7b3766 100644
--- a/linters/ineffassign/ineffassign.go
+++ b/linters/ineffassign/ineffassign.go
@@ -4,7 +4,7 @@ func storeCounter(counter int) {
 	_ = counter
 }
 
-func ineffassign() {
+func fn() {
 	var counter int
 
 	// do something

From aaa5a534889bca2b1b5a9c6e2e1c9f64443e97b4 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Fri, 26 Aug 2022 15:21:36 +0300
Subject: [PATCH 11/12] removed redundant

---
 linters/.golangci.yml | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/linters/.golangci.yml b/linters/.golangci.yml
index bf7c99a..0409d76 100644
--- a/linters/.golangci.yml
+++ b/linters/.golangci.yml
@@ -53,11 +53,8 @@ linters-settings:
       - performance
       - style
     disabled-checks:
-      - commentedOutCode
       - dupImport # https://github.com/go-critic/go-critic/issues/845
-      - octalLiteral
-      - wrapperFunc
-      - whyNoLint
+      - whyNoLint # checked by nolintlint
       - hugeParam # TODO: configure(80 bytes is probably not so much) and enable.
 
   errcheck:

From 22fd7f0872dd79085622878bb7b920e4f9b6b8d5 Mon Sep 17 00:00:00 2001
From: vtopc <32271530+vtopc@users.noreply.github.com>
Date: Fri, 30 Sep 2022 22:30:09 +0300
Subject: [PATCH 12/12] staticcheck2

---
 linters/errs/staticcheck.go      | 7 ++++++-
 linters/errs/staticcheck_test.go | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/linters/errs/staticcheck.go b/linters/errs/staticcheck.go
index c0e7e8d..8f989a7 100644
--- a/linters/errs/staticcheck.go
+++ b/linters/errs/staticcheck.go
@@ -1,7 +1,12 @@
 package errs
 
-func staticcheck() (err error) {
+func staticcheck1() (err error) {
 	err = fnWithError()
 	err = fnNoError()
 	return
 }
+
+func staticcheck2() (err error) {
+	err = fnNoError()
+	return fnWithError()
+}
diff --git a/linters/errs/staticcheck_test.go b/linters/errs/staticcheck_test.go
index e0f8ab5..67ea07b 100644
--- a/linters/errs/staticcheck_test.go
+++ b/linters/errs/staticcheck_test.go
@@ -7,6 +7,6 @@ import (
 )
 
 func Test_staticcheck(t *testing.T) {
-	err := staticcheck()
+	err := staticcheck1()
 	require.Error(t, err)
 }