feat: syntax to not override severity from linters (#4472)

.golangci.reference.yml

@@ -2881,6 +2881,8 @@ severity:
   # - GitHub: https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message
   # - TeamCity: https://www.jetbrains.com/help/teamcity/service-messages.html#Inspection+Instance
   #
+  # `@linter` can be used as severity value to keep the severity from linters (e.g. revive, gosec, ...)
+  #
   # Default: ""
   default-severity: error
 
@@ -2888,13 +2890,12 @@ severity:
   # Default: false
   case-sensitive: true
 
-  # Don't override severity defined by linters.
-  # Default: false
-  keep-linter-severity: true
-
   # When a list of severity rules are provided, severity information will be added to lint issues.
   # Severity rules have the same filtering capability as exclude rules
   # except you are allowed to specify one matcher per severity rule.
+  #
+  # `@linter` can be used as severity value to keep the severity from linters (e.g. revive, gosec, ...)
+  #
   # Only affects out formats that support setting severity information.
   #
   # Default: []

pkg/config/severity.go

@@ -8,10 +8,9 @@ import (
 const severityRuleMinConditionsCount = 1
 
 type Severity struct {
-	Default            string         `mapstructure:"default-severity"`
-	CaseSensitive      bool           `mapstructure:"case-sensitive"`
-	Rules              []SeverityRule `mapstructure:"rules"`
-	KeepLinterSeverity bool           `mapstructure:"keep-linter-severity"` // TODO(ldez): in v2 should be changed to `Override`.
+	Default       string         `mapstructure:"default-severity"`
+	CaseSensitive bool           `mapstructure:"case-sensitive"`
+	Rules         []SeverityRule `mapstructure:"rules"`
 }
 
 func (s *Severity) Validate() error {

pkg/lint/runner.go

@@ -302,7 +302,6 @@ func getSeverityRulesProcessor(cfg *config.Severity, log logutils.Log, files *fs
 		Default:       cfg.Default,
 		Rules:         severityRules,
 		CaseSensitive: cfg.CaseSensitive,
-		Override:      !cfg.KeepLinterSeverity,
 	}
 
 	return processors.NewSeverity(log.Child(logutils.DebugKeySeverityRules), files, severityOpts)

pkg/result/processors/processor_test.go

@@ -22,6 +22,7 @@ func newIssueFromIssueTestCase(c issueTestCase) result.Issue {
 	return result.Issue{
 		Text:       c.Text,
 		FromLinter: c.Linter,
+		Severity:   c.Severity,
 		Pos: token.Position{
 			Filename: c.Path,
 			Line:     c.Line,

pkg/result/processors/severity.go

@@ -8,6 +8,8 @@ import (
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
+const severityFromLinter = "@linter"
+
 var _ Processor = &Severity{}
 
 type severityRule struct {
@@ -24,7 +26,6 @@ type SeverityOptions struct {
 	Default       string
 	Rules         []SeverityRule
 	CaseSensitive bool
-	Override      bool
 }
 
 type Severity struct {
@@ -36,7 +37,6 @@ type Severity struct {
 
 	defaultSeverity string
 	rules           []severityRule
-	override        bool
 }
 
 func NewSeverity(log logutils.Log, files *fsutils.Files, opts SeverityOptions) *Severity {
@@ -45,7 +45,6 @@ func NewSeverity(log logutils.Log, files *fsutils.Files, opts SeverityOptions) *
 		files:           files,
 		log:             log,
 		defaultSeverity: opts.Default,
-		override:        opts.Override,
 	}
 
 	prefix := caseInsensitivePrefix
@@ -64,29 +63,30 @@ func (p *Severity) Process(issues []result.Issue) ([]result.Issue, error) {
 		return issues, nil
 	}
 
-	return transformIssues(issues, func(issue *result.Issue) *result.Issue {
-		if issue.Severity != "" && !p.override {
-			return issue
-		}
+	return transformIssues(issues, p.transform), nil
+}
 
-		for _, rule := range p.rules {
-			rule := rule
-
-			ruleSeverity := p.defaultSeverity
-			if rule.severity != "" {
-				ruleSeverity = rule.severity
-			}
-
-			if rule.match(issue, p.files, p.log) {
-				issue.Severity = ruleSeverity
+func (p *Severity) transform(issue *result.Issue) *result.Issue {
+	for _, rule := range p.rules {
+		if rule.match(issue, p.files, p.log) {
+			if rule.severity == severityFromLinter || rule.severity == "" && p.defaultSeverity == severityFromLinter {
 				return issue
 			}
+
+			issue.Severity = rule.severity
+			if issue.Severity == "" {
+				issue.Severity = p.defaultSeverity
+			}
+
+			return issue
 		}
+	}
 
+	if p.defaultSeverity != severityFromLinter {
 		issue.Severity = p.defaultSeverity
+	}
 
-		return issue
-	}), nil
+	return issue
 }
 
 func (p *Severity) Name() string { return p.name }

pkg/result/processors/severity_test.go

@@ -310,3 +310,187 @@ func TestSeverity_caseSensitive(t *testing.T) {
 
 	assert.Equal(t, expectedCases, resultingCases)
 }
+
+func TestSeverity_transform(t *testing.T) {
+	lineCache := fsutils.NewLineCache(fsutils.NewFileCache())
+	files := fsutils.NewFiles(lineCache, "")
+
+	testCases := []struct {
+		desc     string
+		opts     SeverityOptions
+		issue    *result.Issue
+		expected *result.Issue
+	}{
+		{
+			desc: "apply severity from rule",
+			opts: SeverityOptions{
+				Default: "error",
+				Rules: []SeverityRule{
+					{
+						Severity: "info",
+						BaseRule: BaseRule{
+							Linters: []string{"linter1"},
+						},
+					},
+				},
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter1",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter1",
+				Severity:   "info",
+			},
+		},
+		{
+			desc: "apply severity from default",
+			opts: SeverityOptions{
+				Default: "error",
+				Rules: []SeverityRule{
+					{
+						Severity: "info",
+						BaseRule: BaseRule{
+							Linters: []string{"linter1"},
+						},
+					},
+				},
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "error",
+			},
+		},
+		{
+			desc: "severity from rule override severity from linter",
+			opts: SeverityOptions{
+				Default: "error",
+				Rules: []SeverityRule{
+					{
+						Severity: "info",
+						BaseRule: BaseRule{
+							Linters: []string{"linter1"},
+						},
+					},
+				},
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter1",
+				Severity:   "huge",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter1",
+				Severity:   "info",
+			},
+		},
+		{
+			desc: "severity from default override severity from linter",
+			opts: SeverityOptions{
+				Default: "error",
+				Rules: []SeverityRule{
+					{
+						Severity: "info",
+						BaseRule: BaseRule{
+							Linters: []string{"linter1"},
+						},
+					},
+				},
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "huge",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "error",
+			},
+		},
+		{
+			desc: "keep severity from linter as rule",
+			opts: SeverityOptions{
+				Default: "error",
+				Rules: []SeverityRule{
+					{
+						Severity: severityFromLinter,
+						BaseRule: BaseRule{
+							Linters: []string{"linter1"},
+						},
+					},
+				},
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter1",
+				Severity:   "huge",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter1",
+				Severity:   "huge",
+			},
+		},
+		{
+			desc: "keep severity from linter as default",
+			opts: SeverityOptions{
+				Default: severityFromLinter,
+				Rules: []SeverityRule{
+					{
+						Severity: "info",
+						BaseRule: BaseRule{
+							Linters: []string{"linter1"},
+						},
+					},
+				},
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "huge",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "huge",
+			},
+		},
+		{
+			desc: "keep severity from linter as default (without rule)",
+			opts: SeverityOptions{
+				Default: severityFromLinter,
+			},
+			issue: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "huge",
+			},
+			expected: &result.Issue{
+				Text:       "This is a report",
+				FromLinter: "linter2",
+				Severity:   "huge",
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			p := NewSeverity(nil, files, test.opts)
+
+			newIssue := p.transform(test.issue)
+
+			assert.Equal(t, test.expected, newIssue)
+		})
+	}
+}