feat: add new issues.new-from-merge-base option

Author: ldez

.golangci.next.reference.yml

@@ -4043,6 +4043,10 @@ issues:
   # Default: false
   new: true
 
+  # Show only new issues created after the best common ancestor (merge-base against HEAD).
+  # Default: ""
+  new-from-merge-base: main
+
   # Show only new issues created after git revision `REV`.
   # Default: ""
   new-from-rev: HEAD

go.mod

@@ -48,7 +48,7 @@ require (
 	github.com/golangci/gofmt v0.0.0-20250106114630-d62b90e6713d
 	github.com/golangci/misspell v0.6.0
 	github.com/golangci/plugin-module-register v0.1.1
-	github.com/golangci/revgrep v0.7.0
+	github.com/golangci/revgrep v0.8.0
 	github.com/golangci/unconvert v0.0.0-20240309020433-c5143eacb3ed
 	github.com/gordonklaus/ineffassign v0.1.0
 	github.com/gostaticanalysis/forcetypeassert v0.1.0

go.sum

@@ -4081,6 +4081,10 @@
           "type": "boolean",
           "default": false
         },
+        "new-from-merge-base": {
+          "description": "Show only new issues created after the best common ancestor (merge-base against HEAD).",
+          "type": "string"
+        },
         "new-from-rev": {
           "description": "Show only new issues created after this git revision.",
           "type": "string"

jsonschema/golangci.next.jsonschema.json

@@ -118,6 +118,7 @@ type Issues struct {
 	UniqByLine         bool `mapstructure:"uniq-by-line"`
 
 	DiffFromRevision  string `mapstructure:"new-from-rev"`
+	DiffFromMergeBase string `mapstructure:"new-from-merge-base"`
 	DiffPatchFilePath string `mapstructure:"new-from-patch"`
 	WholeFiles        bool   `mapstructure:"whole-files"`
 	Diff              bool   `mapstructure:"new"`

pkg/config/issues.go

@@ -27,6 +27,7 @@ var _ Processor = (*Diff)(nil)
 type Diff struct {
 	onlyNew       bool
 	fromRev       string
+	fromMergeBase string
 	patchFilePath string
 	wholeFiles    bool
 	patch         string
@@ -36,6 +37,7 @@ func NewDiff(cfg *config.Issues) *Diff {
 	return &Diff{
 		onlyNew:       cfg.Diff,
 		fromRev:       cfg.DiffFromRevision,
+		fromMergeBase: cfg.DiffFromMergeBase,
 		patchFilePath: cfg.DiffPatchFilePath,
 		wholeFiles:    cfg.WholeFiles,
 		patch:         os.Getenv(envGolangciDiffProcessorPatch),
@@ -47,7 +49,7 @@ func (*Diff) Name() string {
 }
 
 func (p *Diff) Process(issues []result.Issue) ([]result.Issue, error) {
-	if !p.onlyNew && p.fromRev == "" && p.patchFilePath == "" && p.patch == "" {
+	if !p.onlyNew && p.fromRev == "" && p.fromMergeBase == "" && p.patchFilePath == "" && p.patch == "" {
 		return issues, nil
 	}
 
@@ -68,6 +70,7 @@ func (p *Diff) Process(issues []result.Issue) ([]result.Issue, error) {
 	checker := revgrep.Checker{
 		Patch:        patchReader,
 		RevisionFrom: p.fromRev,
+		MergeBase:    p.fromMergeBase,
 		WholeFiles:   p.wholeFiles,
 	}