chore(ci): add golangci-lint action and apply linting changes (#120)

BREAKING CHANGE: `JiraIssueId` has been renamed to `JiraIssueID`. This impacts the value for `pattern_maps` in `config.yml`.

* chore(ci): add golangci-lint action

* chore(lint): address errcheck lint failures

* chore(lint): address misspell lint failures

* chore(lint): address gocritic lint failures

* chore(lint): address golint lint failures

* chore(lint): address structcheck lint failures

* chore(lint): address gosimple lint failures

* chore(lint): address gofmt lint failures

* chore(ci): port to official golangci-lint github action

* Update golangci configuration for better coverage

Signed-off-by: Khosrow Moossavi <khos2ow@gmail.com>

* fix: file is not goimports-ed

Signed-off-by: Khosrow Moossavi <khos2ow@gmail.com>

* fix: golint and exported functions comments

Signed-off-by: Khosrow Moossavi <khos2ow@gmail.com>

* chore(lint): address gosec G304 warning

* chore(lint): address uparam warnings

* chore(lint): address scopelint lint failures

* fix: cyclomatic complexity

Signed-off-by: Khosrow Moossavi <khos2ow@gmail.com>

* chore(lint): address prealloc warning, noting that we are warning for now

* chore(lint): address govet and errorlint failures

* chore: clean up defer logic when checking errors

Co-authored-by: Khosrow Moossavi <khos2ow@gmail.com>

.github/workflows/lint.yml

@@ -0,0 +1,18 @@
+name: lint
+
+on:
+  pull_request:
+    types: ['opened', 'synchronize']
+  push:
+    branches:
+      - master
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v2
+        with:
+          version: v1.38

.golangci.yml

@@ -0,0 +1,155 @@
+# https://golangci-lint.run/usage/configuration/
+run:
+  timeout: 10m
+  deadline: 5m
+
+  tests: true
+
+output:
+  format: tab
+
+linters-settings:
+  govet:
+    # report about shadowed variables
+    check-shadowing: true
+
+  golint:
+    # minimal confidence for issues, default is 0.8
+    min-confidence: 0.8
+
+  gofmt:
+    # simplify code: gofmt with `-s` option, true by default
+    simplify: true
+
+  goimports:
+    # put imports beginning with prefix after 3rd-party packages;
+    # it's a comma-separated list of prefixes
+    local-prefixes: github.com/git-chglog/git-chglog
+
+  gocyclo:
+    # minimal code complexity to report, 30 by default (but we recommend 10-20)
+    min-complexity: 10
+
+  maligned:
+    # print struct with more effective memory layout or not, false by default
+    suggest-new: true
+
+  dupl:
+    # tokens count to trigger issue, 150 by default
+    threshold: 100
+
+  goconst:
+    # minimal length of string constant, 3 by default
+    min-len: 3
+    # minimal occurrences count to trigger, 3 by default
+    min-occurrences: 5
+
+  lll:
+    # tab width in spaces. Default to 1.
+    tab-width: 1
+
+  unused:
+    # treat code as a program (not a library) and report unused exported identifiers; default is false.
+    # XXX: if you enable this setting, unused will report a lot of false-positives in text editors:
+    # if it's called for subdir of a project it can't find funcs usages. All text editor integrations
+    # with golangci-lint call it on a directory with the changed file.
+    check-exported: false
+
+  unparam:
+    # Inspect exported functions, default is false. Set to true if no external program/library imports your code.
+    # XXX: if you enable this setting, unparam will report a lot of false-positives in text editors:
+    # if it's called for subdir of a project it can't find external interfaces. All text editor integrations
+    # with golangci-lint call it on a directory with the changed file.
+    check-exported: false
+
+  nakedret:
+    # make an issue if func has more lines of code than this setting and it has naked returns; default is 30
+    max-func-lines: 30
+
+  prealloc:
+    # XXX: we don't recommend using this linter before doing performance profiling.
+    # For most programs usage of prealloc will be a premature optimization.
+
+    # Report preallocation suggestions only on simple loops that have no returns/breaks/continues/gotos in them.
+    # True by default.
+    simple: true
+    range-loops: true # Report preallocation suggestions on range loops, true by default
+    for-loops: false # Report preallocation suggestions on for loops, false by default
+
+  gocritic:
+    # Enable multiple checks by tags, run `GL_DEBUG=gocritic golangci-lint` run to see all tags and checks.
+    # Empty list by default. See https://github.com/go-critic/go-critic#usage -> section "Tags".
+    enabled-tags:
+      - performance
+
+    settings: # settings passed to gocritic
+      captLocal: # must be valid enabled check name
+        paramsOnly: true
+      rangeValCopy:
+        sizeThreshold: 32
+
+  misspell:
+    locale: US
+
+linters:
+  enable:
+    - megacheck
+    - govet
+    - gocyclo
+    - gocritic
+    - interfacer
+    - goconst
+    - goimports
+    - gofmt  # We enable this as well as goimports for its simplify mode.
+    - prealloc
+    - golint
+    - unconvert
+    - misspell
+    - nakedret
+    - dupl
+    - depguard
+
+  presets:
+    - bugs
+    - unused
+  fast: false
+
+issues:
+  # Excluding configuration per-path and per-linter
+  exclude-rules:
+    # Exclude some linters from running on tests files.
+    - path: _test(ing)?\.go
+      linters:
+        - gocyclo
+        - errcheck
+        - dupl
+        - gosec
+        - scopelint
+        - unparam
+
+    # These are performance optimisations rather than style issues per se.
+    # They warn when function arguments or range values copy a lot of memory
+    # rather than using a pointer.
+    - text: "(hugeParam|rangeValCopy):"
+      linters:
+      - gocritic
+
+  # Independently from option `exclude` we use default exclude patterns,
+  # it can be disabled by this option. To list all
+  # excluded by default patterns execute `golangci-lint run --help`.
+  # Default value for this option is true.
+  exclude-use-default: false
+
+  # Show only new issues: if there are unstaged changes or untracked files,
+  # only those changes are analyzed, else only changes in HEAD~ are analyzed.
+  # It's a super-useful option for integration of golangci-lint into existing
+  # large codebase. It's not practical to fix all existing issues at the moment
+  # of integration: much better don't allow issues in new code.
+  # Default is false.
+  new: false
+
+  # Maximum issues count per one linter. Set to 0 to disable. Default is 50.
+  max-per-linter: 0
+
+  # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
+  max-same-issues: 0

Makefile

@@ -20,3 +20,7 @@ install:
 .PHONY: changelog
 changelog:
 	@git-chglog --next-tag $(tag) $(tag)
+
+.PHONY: lint
+lint:
+	@golangci-lint run

README.md

@@ -522,7 +522,7 @@ The following is a sample pattern:
     pattern: "^(?:(\\w*)|(?:\\[(.*)\\])?)\\:\\s(.*)$"
     pattern_maps:
       - Type
-      - JiraIssueId
+      - JiraIssueID
       - Subject
   ```
 
@@ -646,6 +646,8 @@ We alway welcome your contributions :clap:
 1. Fork (https://github.com/git-chglog/git-chglog) :tada:
 1. Create a feature branch :coffee:
 1. Run test suite with the `$ make test` command and confirm that it passes :zap:
+1. Run linters with the `$ make lint` command and confirm it passes :broom:
+   - The project uses [golangci-lint](https://golangci-lint.run/usage/install/#local-installation)
 1. Commit your changes :memo:
 1. Rebase your local changes against the `master` branch :bulb:
 1. Create new Pull Request :love_letter:

chglog.go

@@ -5,13 +5,14 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"path/filepath"
 	"strings"
 	"text/template"
 	"time"
 
-	gitcmd "github.com/tsuyoshiwada/go-gitcmd"
+	"github.com/tsuyoshiwada/go-gitcmd"
 )
 
 // Options is an option used to process commits
@@ -37,7 +38,7 @@ type Options struct {
 	NoteKeywords                []string            // Keyword list to find `Note`. A semicolon is a separator, like `<keyword>:` (e.g. `BREAKING CHANGE`)
 	JiraUsername                string
 	JiraToken                   string
-	JiraUrl                     string
+	JiraURL                     string
 	JiraTypeMaps                map[string]string
 	JiraIssueDescriptionPattern string
 	Paths                       []string // Path filter
@@ -138,7 +139,11 @@ func (gen *Generator) Generate(w io.Writer, query string) error {
 	if err != nil {
 		return err
 	}
-	defer back()
+	defer func() {
+		if err = back(); err != nil {
+			log.Fatal(err)
+		}
+	}()
 
 	tags, first, err := gen.getTags(query)
 	if err != nil {
@@ -269,7 +274,7 @@ func (gen *Generator) getTags(query string) ([]*Tag, string, error) {
 
 		// Assign the date with `readVersions()`
 		tags = append([]*Tag{
-			&Tag{
+			{
 				Name:     next,
 				Subject:  next,
 				Previous: previous,
@@ -318,30 +323,18 @@ func (gen *Generator) render(w io.Writer, unreleased *Unreleased, versions []*Ve
 		"datetime": func(layout string, input time.Time) string {
 			return input.Format(layout)
 		},
-		// check whether substs is withing s
-		"contains": func(s, substr string) bool {
-			return strings.Contains(s, substr)
-		},
+		// check whether substr is within s
+		"contains": strings.Contains,
 		// check whether s begins with prefix
-		"hasPrefix": func(s, prefix string) bool {
-			return strings.HasPrefix(s, prefix)
-		},
+		"hasPrefix": strings.HasPrefix,
 		// check whether s ends with suffix
-		"hasSuffix": func(s, suffix string) bool {
-			return strings.HasSuffix(s, suffix)
-		},
+		"hasSuffix": strings.HasSuffix,
 		// replace the first n instances of old with new
-		"replace": func(s, old, new string, n int) string {
-			return strings.Replace(s, old, new, n)
-		},
+		"replace": strings.Replace,
 		// lower case a string
-		"lower": func(s string) string {
-			return strings.ToLower(s)
-		},
+		"lower": strings.ToLower,
 		// upper case a string
-		"upper": func(s string) string {
-			return strings.ToUpper(s)
-		},
+		"upper": strings.ToUpper,
 		// upper case the first character of a string
 		"upperFirst": func(s string) string {
 			if len(s) > 0 {