add files

main.go

@@ -0,0 +1,111 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/go-git/go-git/v5/plumbing/format/gitignore"
+	gha "github.com/sethvargo/go-githubactions"
+)
+
+func main() {
+	ghCtx, err := gha.Context()
+	if err != nil {
+		gha.Fatalf("gha.Context error: %v", err)
+	}
+	workdir := gha.GetInput("workdir")
+	if len(workdir) == 0 {
+		workdir = ghCtx.Workspace
+	}
+
+	inputPatterns := gha.GetInput("patterns")
+	gha.Infof("input patterns: %s", inputPatterns)
+	matchedFiles, hashResult, err := hashFiles(workdir, strings.Split(inputPatterns, "\n"))
+	if err != nil {
+		gha.Fatalf("hashFiles error: %v", err)
+	}
+
+	gha.SetOutput("hash", hashResult)
+	gha.Infof("computed hash: %s", hashResult)
+
+	matchedFilesJSON, _ := json.Marshal(matchedFiles)
+	gha.SetOutput("matched-files", string(matchedFilesJSON))
+	gha.Infof("matched files: %s", matchedFilesJSON)
+}
+
+func hashFiles(workdir string, patterns []string) ([]string, string, error) {
+	var ps []gitignore.Pattern
+
+	const cwdPrefix = "." + string(filepath.Separator)
+	const excludeCwdPrefix = "!" + cwdPrefix
+
+	for _, p := range patterns {
+		cleanPattern := strings.TrimSpace(p)
+		if len(cleanPattern) == 0 {
+			continue
+		}
+		if strings.HasPrefix(cleanPattern, cwdPrefix) {
+			cleanPattern = cleanPattern[len(cwdPrefix):]
+		} else if strings.HasPrefix(cleanPattern, excludeCwdPrefix) {
+			cleanPattern = "!" + cleanPattern[len(excludeCwdPrefix):]
+		}
+		ps = append(ps, gitignore.ParsePattern(cleanPattern, nil))
+	}
+
+	matcher := gitignore.NewMatcher(ps)
+
+	var files []string
+	if err := filepath.Walk(workdir, func(path string, fi fs.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		sansPrefix := strings.TrimPrefix(path, workdir+string(filepath.Separator))
+		parts := strings.Split(sansPrefix, string(filepath.Separator))
+		if fi.IsDir() || !matcher.Match(parts, fi.IsDir()) {
+			return nil
+		}
+		files = append(files, path)
+		return nil
+	}); err != nil {
+		return nil, "", fmt.Errorf("unable to filepath.Walk: %v", err)
+	}
+
+	if len(files) == 0 {
+		return nil, "", nil
+	}
+
+	matchedFiles := make([]string, 0, len(files))
+	resultHasher := sha256.New()
+
+	for _, file := range files {
+		f, err := os.Open(file)
+		if err != nil {
+			return nil, "", fmt.Errorf("unable to os.Open: %v", err)
+		}
+
+		hasher := sha256.New()
+
+		if _, err := io.Copy(hasher, f); err != nil {
+			return nil, "", fmt.Errorf("unable to io.Copy: %v", err)
+		}
+
+		if err := f.Close(); err != nil {
+			return nil, "", fmt.Errorf("unable to Close file: %v", err)
+		}
+
+		if _, err := resultHasher.Write(hasher.Sum(nil)); err != nil {
+			return nil, "", fmt.Errorf("unable to write resultHasher: %v", err)
+		}
+
+		matchedFiles = append(matchedFiles, strings.TrimPrefix(file, workdir+string(filepath.Separator)))
+	}
+
+	return matchedFiles, hex.EncodeToString(resultHasher.Sum(nil)), nil
+}