Fix check_generate script and add it to ci

Author: joshklop

.circleci/config.yml

@@ -194,6 +194,8 @@ jobs:
       - checkout
       - run:
           command: go run build/ci.go lint
+      - run:
+          command: go run build/ci.go check_generate
   tidy-geth:
     resource_class: small
     docker:

build/ci.go

@@ -378,7 +378,7 @@ func doCheckGenerate() {
 
 	for _, mod := range goModules {
 		// Compute the origin hashes of all the files
-		hashes, err := build.HashFolder(mod, []string{"tests/testdata", "build/cache", ".git"})
+		hashes, err := build.HashFolder(mod, []string{"tests/testdata", "build/cache", ".git", ".jj"})
 		if err != nil {
 			log.Fatal("Error computing hashes", "err", err)
 		}
@@ -388,7 +388,7 @@ func doCheckGenerate() {
 		c.Dir = mod
 		build.MustRun(c)
 		// Check if generate file hashes have changed
-		generated, err := build.HashFolder(mod, []string{"tests/testdata", "build/cache", ".git"})
+		generated, err := build.HashFolder(mod, []string{"tests/testdata", "build/cache", ".git", ".jj"})
 		if err != nil {
 			log.Fatalf("Error re-computing hashes: %v", err)
 		}

internal/build/file.go

@@ -40,9 +40,11 @@ func HashFolder(folder string, exlude []string) (map[string][32]byte, error) {
 	res := make(map[string][32]byte)
 	err := filepath.WalkDir(folder, func(path string, d os.DirEntry, _ error) error {
 		// Skip anything that's exluded or not a regular file
-		for _, skip := range exlude {
-			if strings.HasPrefix(path, filepath.FromSlash(skip)) {
-				return filepath.SkipDir
+		if d.IsDir() {
+			for _, skip := range exlude {
+				if strings.HasPrefix(path, filepath.FromSlash(skip)) {
+					return filepath.SkipDir
+				}
 			}
 		}
 		if !d.Type().IsRegular() {