s

gitcmd/merge.go

@@ -0,0 +1,81 @@
+package gitcmd
+
+import (
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+type MergeResult struct {
+	Base        string   `json:"base"`
+	Head        string   `json:"head"`
+	MergeCommit *Commit  `json:"merge_commit,omitempty"`
+	FastForward bool     `json:"fast_forward"`
+	Conflicts   []string `json:"conflicts,omitempty"`
+}
+
+func (r *Repository) Merge(base, head, message, authorName, authorEmail string, noFF bool) (*MergeResult, error) {
+	baseSHA, err := r.refSHA("refs/heads/" + base)
+	if err != nil || baseSHA == "" {
+		return nil, fmt.Errorf("base branch %q not found", base)
+	}
+	headSHA, err := r.refSHA("refs/heads/" + head)
+	if err != nil || headSHA == "" {
+		return nil, fmt.Errorf("head branch %q not found", head)
+	}
+
+	if !noFF && r.isAncestor(baseSHA, headSHA) {
+		if err := r.updateRef("refs/heads/"+base, headSHA, baseSHA); err != nil {
+			return nil, err
+		}
+		hc, err := r.GetCommit(headSHA)
+		if err != nil {
+			return nil, err
+		}
+		return &MergeResult{Base: base, Head: head, MergeCommit: hc, FastForward: true}, nil
+	}
+
+	out, _, err := NewCommand("merge-tree", "--write-tree", "-z", "--name-only", "--no-messages").
+		AddDynamicArguments(baseSHA, headSHA).
+		WithDir(r.Path).RunStdString(r.ctx)
+
+	conflict := false
+	if err != nil {
+		var exitErr *exec.ExitError
+		if errors.As(err, &exitErr) && exitErr.ExitCode() == 1 {
+			conflict = true
+		} else {
+			return nil, fmt.Errorf("merge-tree: %w", err)
+		}
+	}
+
+	parts := strings.Split(out, "\x00")
+	if len(parts) == 0 || strings.TrimSpace(parts[0]) == "" {
+		return nil, fmt.Errorf("merge-tree: empty output")
+	}
+	mergedTree := strings.TrimSpace(parts[0])
+
+	if conflict {
+		var conflicts []string
+		for i := 1; i < len(parts); i++ {
+			if p := strings.TrimSpace(parts[i]); p != "" {
+				conflicts = append(conflicts, p)
+			}
+		}
+		return &MergeResult{Base: base, Head: head, Conflicts: conflicts}, nil
+	}
+
+	commitSHA, err := r.commitTree(mergedTree, message, authorName, authorEmail, r.Path, baseSHA, headSHA)
+	if err != nil {
+		return nil, err
+	}
+	if err := r.updateRef("refs/heads/"+base, commitSHA, baseSHA); err != nil {
+		return nil, err
+	}
+	mc, err := r.GetCommit(commitSHA)
+	if err != nil {
+		return nil, err
+	}
+	return &MergeResult{Base: base, Head: head, MergeCommit: mc}, nil
+}