[minion] Content-aware carry-forward for accurate 1:1 checkpoint-to-commit mapping

internal/git/staged_files.go

@@ -0,0 +1,39 @@
+package git
+
+import "strings"
+
+// StagedFiles returns the list of file paths staged for commit.
+func StagedFiles() ([]string, error) {
+	out, err := execGit("diff", "--cached", "--name-only")
+	if err != nil {
+		return nil, err
+	}
+	if out == "" {
+		return nil, nil
+	}
+	return strings.Split(out, "\n"), nil
+}
+
+// CommittedFiles returns the list of file paths changed in a specific commit.
+func CommittedFiles(commitHash string) ([]string, error) {
+	out, err := execGit("diff", "--name-only", commitHash+"~1", commitHash)
+	if err != nil {
+		return nil, err
+	}
+	if out == "" {
+		return nil, nil
+	}
+	return strings.Split(out, "\n"), nil
+}
+
+// UnstagedFiles returns the list of file paths with unstaged modifications.
+func UnstagedFiles() ([]string, error) {
+	out, err := execGit("diff", "--name-only")
+	if err != nil {
+		return nil, err
+	}
+	if out == "" {
+		return nil, nil
+	}
+	return strings.Split(out, "\n"), nil
+}

internal/hooks/carryforward.go

@@ -0,0 +1,103 @@
+package hooks
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+)
+
+const carryForwardFile = "carry-forward.json"
+
+// carryForwardState records agent-modified files not yet committed, enabling
+// agent attribution to carry over to subsequent partial commits.
+type carryForwardState struct {
+	SessionPath  string   `json:"session_path"`
+	PendingFiles []string `json:"pending_files"`
+	Branch       string   `json:"branch"`
+}
+
+func loadCarryForward(stateDir string) (*carryForwardState, error) {
+	data, err := os.ReadFile(filepath.Join(stateDir, carryForwardFile))
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	var cf carryForwardState
+	if err := json.Unmarshal(data, &cf); err != nil {
+		return nil, err
+	}
+	return &cf, nil
+}
+
+func saveCarryForward(stateDir string, cf *carryForwardState) error {
+	if err := os.MkdirAll(stateDir, 0o755); err != nil {
+		return err
+	}
+	data, err := json.Marshal(cf)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(filepath.Join(stateDir, carryForwardFile), data, 0o644)
+}
+
+func clearCarryForward(stateDir string) {
+	_ = os.Remove(filepath.Join(stateDir, carryForwardFile))
+}
+
+// computeCarryForward returns files from allAgentFiles that were not committed.
+func computeCarryForward(allAgentFiles, committedFiles []string) []string {
+	if len(allAgentFiles) == 0 {
+		return nil
+	}
+	committed := make(map[string]bool, len(committedFiles))
+	for _, f := range committedFiles {
+		committed[f] = true
+	}
+	var pending []string
+	for _, f := range allAgentFiles {
+		if !committed[f] {
+			pending = append(pending, f)
+		}
+	}
+	return pending
+}
+
+// checkCarryForwardActivation returns whether a carry-forward state should
+// activate agent attribution for the given staged files, and the session path.
+func checkCarryForwardActivation(cf *carryForwardState, stagedFiles []string) (activate bool, sessionPath string) {
+	if cf == nil || len(cf.PendingFiles) == 0 {
+		return false, ""
+	}
+	staged := make(map[string]bool, len(stagedFiles))
+	for _, f := range stagedFiles {
+		staged[f] = true
+	}
+	for _, f := range cf.PendingFiles {
+		if staged[f] {
+			return true, cf.SessionPath
+		}
+	}
+	return false, ""
+}
+
+// mergeFiles returns the union of two file slices without duplicates.
+func mergeFiles(a, b []string) []string {
+	seen := make(map[string]bool, len(a)+len(b))
+	var result []string
+	for _, f := range a {
+		if !seen[f] {
+			seen[f] = true
+			result = append(result, f)
+		}
+	}
+	for _, f := range b {
+		if !seen[f] {
+			seen[f] = true
+			result = append(result, f)
+		}
+	}
+	return result
+}