cmd/evm: make evm statetest accept non-json files (#30927)

This fixes a regression introduced recently. Without this fix, it's not
possible to use statetests without `.json` suffix. This is problematic for
goevmlab `minimizer`, which appends the suffix `.min` during processing.

cmd/evm/blockrunner.go

@@ -50,7 +50,7 @@ func blockTestCmd(ctx *cli.Context) error {
 		return errors.New("path argument required")
 	}
 	var (
-		collected = collectJSONFiles(path)
+		collected = collectFiles(path)
 		results   []testResult
 	)
 	for _, fname := range collected {

cmd/evm/main.go

@@ -262,10 +262,15 @@ func tracerFromFlags(ctx *cli.Context) *tracing.Hooks {
 	}
 }
 
-// collectJSONFiles walks the given path and accumulates all files with json
+// collectFiles walks the given path. If the path is a directory, it will
-// extension.
+// return a list of all accumulates all files with json extension.
-func collectJSONFiles(path string) []string {
+// Otherwise (if path points to a file), it will return the path.
+func collectFiles(path string) []string {
 	var out []string
+	if info, err := os.Stat(path); err == nil && !info.IsDir() {
+		// User explicitly pointed out a file, ignore extension.
+		return []string{path}
+	}
 	err := filepath.Walk(path, func(path string, info fs.FileInfo, err error) error {
 		if err != nil {
 			return err

cmd/evm/staterunner.go

@@ -63,7 +63,7 @@ func stateTestCmd(ctx *cli.Context) error {
 	// If path is provided, run the tests at that path.
 	if len(path) != 0 {
 		var (
-			collected = collectJSONFiles(path)
+			collected = collectFiles(path)
 			results   []testResult
 		)
 		for _, fname := range collected {