fix: eslint errors (denoland/deno_std#265)

Original: https://github.com/denoland/deno_std/commit/61af419bbc5717c2e2552050aacb20ef1b17480b

1 files changed, 1 insertions, 1 deletions

diff --git a/format.ts b/format.ts
index d5878f27b..80bde59de 100755
--- a/format.ts
+++ b/format.ts
@@ -4,7 +4,7 @@ const { exit, args, execPath } = Deno;
 import { parse } from "./flags/mod.ts";
 import { xrun } from "./prettier/util.ts";
 
-async function main(opts) {
+async function main(opts): Promise<void> {
   const args = [
     execPath,
     "--allow-write",