diff --git a/ignore_test.ts b/ignore_test.ts
index 9659d39..3a75983 100644
--- a/ignore_test.ts
+++ b/ignore_test.ts
@@ -1,8 +1,8 @@
 // Copyright 2020 denolib maintainers. MIT license.
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
-import { test, runIfMain } from "https://deno.land/std/testing/mod.ts";
 import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
 import { parse } from "./ignore.ts";
+const { test } = Deno;
 
 const testCases = [
   {
@@ -78,5 +78,3 @@ test({
     }
   }
 });
-
-runIfMain(import.meta);
diff --git a/main.ts b/main.ts
index 7bca82d..2e3d2a1 100755
--- a/main.ts
+++ b/main.ts
@@ -368,8 +368,8 @@ async function* getTargetFiles(
 /**
  * auto detect prettier configuration file and return config if file exist.
  */
-async function autoResolveConfig(): Promise<PrettierBuildInOptions> {
-  const configFileNamesMap = {
+async function autoResolveConfig(): Promise<PrettierBuildInOptions | undefined> {
+  const configFileNamesMap: Record<string, 1 | undefined> = {
     ".prettierrc.json": 1,
     ".prettierrc.yaml": 1,
     ".prettierrc.yml": 1,
@@ -380,11 +380,11 @@ async function autoResolveConfig(): Promise<PrettierBuildInOptions> {
     ".prettierrc.toml": 1
   };
 
-  const files = await Deno.readDir(".");
+  const files = await Deno.readdir(".");
 
   for (const f of files) {
-    if (f.isFile() && configFileNamesMap[f.name]) {
-      const c = await resolveConfig(f.name);
+    if (f.isFile() && configFileNamesMap[f.name!]) {
+      const c = await resolveConfig(f.name!);
       if (c) {
         return c;
       }
@@ -402,7 +402,7 @@ async function autoResolveConfig(): Promise<PrettierBuildInOptions> {
 async function resolveConfig(
   filepath: string
 ): Promise<PrettierBuildInOptions> {
-  let config: PrettierBuildInOptions = undefined;
+  let config: PrettierBuildInOptions | undefined = undefined;
 
   function generateError(msg: string): Error {
     return new Error(`Invalid prettier configuration file: ${msg}.`);
@@ -462,14 +462,14 @@ async function resolveConfig(
       break;
   }
 
-  return config;
+  return config!;
 }
 
 /**
  * auto detect .prettierignore and return pattern if file exist.
  */
 async function autoResolveIgnoreFile(): Promise<Set<string>> {
-  const files = await Deno.readDir(".");
+  const files = await Deno.readdir(".");
 
   for (const f of files) {
     if (f.isFile() && f.name === ".prettierignore") {
@@ -489,7 +489,7 @@ async function resolveIgnoreFile(filepath: string): Promise<Set<string>> {
   return ignore.parse(raw);
 }
 
-async function main(opts): Promise<void> {
+async function main(opts: any): Promise<void> {
   const { help, check, _: args } = opts;
 
   let prettierOpts: PrettierOptions = {
@@ -546,7 +546,11 @@ async function main(opts): Promise<void> {
 
   const files = getTargetFiles(args.length ? args : ["."], ignore);
 
-  const tty = Deno.isTTY();
+  const tty = {
+    stdout: Deno.isatty(Deno.stdout.rid),
+    stderr: Deno.isatty(Deno.stdout.rid),
+    stdin: Deno.isatty(Deno.stdout.rid)
+  };
 
   const shouldReadFromStdin =
     (!tty.stdin && (tty.stdout || tty.stderr)) || !!opts["stdin"];
diff --git a/main_test.ts b/main_test.ts
index ec62b47..12b6c71 100644
--- a/main_test.ts
+++ b/main_test.ts
@@ -1,18 +1,17 @@
 // Copyright 2020 denolib maintainers. MIT license.
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
-import { test, runIfMain } from "https://deno.land/std/testing/mod.ts";
 import { copy, emptyDir } from "https://deno.land/std/fs/mod.ts";
 import { EOL, join } from "https://deno.land/std/path/mod.ts";
 import { xrun } from "./util.ts";
-const { readAll, execPath } = Deno;
+const { readAll, execPath, test } = Deno;
 
 const decoder = new TextDecoder();
 
 async function run(
-  args: string[]
+  cmd: string[]
 ): Promise<{ stdout: string; code: number | undefined }> {
-  const p = xrun({ args, stdout: "piped" });
+  const p = xrun({ cmd, stdout: "piped" });
 
   const stdout = decoder.decode(await readAll(p.stdout!));
   const { code } = await p.status();
@@ -397,7 +396,7 @@ test(async function testPrettierWithAutoConfig(): Promise<void> {
     const cwd = join(testdata, configName);
     const prettierFile = join(Deno.cwd(), "main.ts");
     const { stdout, stderr } = Deno.run({
-      args: [
+      cmd: [
         execPath(),
         "run",
         "--allow-read",
@@ -412,8 +411,9 @@ test(async function testPrettierWithAutoConfig(): Promise<void> {
       cwd
     });
 
-    const output = decoder.decode(await Deno.readAll(stdout));
-    const errMsg = decoder.decode(await Deno.readAll(stderr));
+    // TODO: Fix
+    const output = decoder.decode(await Deno.readAll(stdout as any));
+    const errMsg = decoder.decode(await Deno.readAll(stderr as any));
 
     assertEquals(
       errMsg
@@ -463,7 +463,7 @@ test(async function testPrettierWithSpecifiedConfig(): Promise<void> {
     const cwd = join(testdata, config.dir);
     const prettierFile = join(Deno.cwd(), "main.ts");
     const { stdout, stderr } = Deno.run({
-      args: [
+      cmd: [
         execPath(),
         "run",
         "--allow-read",
@@ -478,8 +478,9 @@ test(async function testPrettierWithSpecifiedConfig(): Promise<void> {
       cwd
     });
 
-    const output = decoder.decode(await Deno.readAll(stdout));
-    const errMsg = decoder.decode(await Deno.readAll(stderr));
+    // TODO: Fix
+    const output = decoder.decode(await Deno.readAll(stdout as any));
+    const errMsg = decoder.decode(await Deno.readAll(stderr as any));
 
     assertEquals(
       errMsg
@@ -498,7 +499,7 @@ test(async function testPrettierWithAutoIgnore(): Promise<void> {
   const cwd = join(testdata, "ignore_file");
   const prettierFile = join(Deno.cwd(), "main.ts");
   const { stdout, stderr } = Deno.run({
-    args: [
+    cmd: [
       execPath(),
       "run",
       "--allow-read",
@@ -513,10 +514,10 @@ test(async function testPrettierWithAutoIgnore(): Promise<void> {
     cwd
   });
 
-  assertEquals(decoder.decode(await Deno.readAll(stderr)), "");
+  assertEquals(decoder.decode(await Deno.readAll(stderr as any)), "");
 
   assertEquals(
-    decoder.decode(await Deno.readAll(stdout)),
+    decoder.decode(await Deno.readAll(stdout as any)),
     `console.log("typescript");\nconsole.log("typescript1");\n`
   );
 });
@@ -526,7 +527,7 @@ test(async function testPrettierWithSpecifiedIgnore(): Promise<void> {
   const cwd = join(testdata, "ignore_file");
   const prettierFile = join(Deno.cwd(), "main.ts");
   const { stdout, stderr } = Deno.run({
-    args: [
+    cmd: [
       execPath(),
       "run",
       "--allow-read",
@@ -541,12 +542,10 @@ test(async function testPrettierWithSpecifiedIgnore(): Promise<void> {
     cwd
   });
 
-  assertEquals(decoder.decode(await Deno.readAll(stderr)), "");
+  assertEquals(decoder.decode(await Deno.readAll(stderr as any)), "");
 
   assertEquals(
-    decoder.decode(await Deno.readAll(stdout)),
+    decoder.decode(await Deno.readAll(stdout as any)),
     `console.log("javascript");\nconsole.log("javascript1");\n`
   );
 });
-
-runIfMain(import.meta);
diff --git a/testdata/opts/0.ts b/testdata/opts/0.ts
index 400e7ee..574f20f 100644
--- a/testdata/opts/0.ts
+++ b/testdata/opts/0.ts
@@ -2,5 +2,5 @@ console.log(0);
 console.log([
     function foo() {},
     function baz() {},
-    a => {}
+    (_: any) => {}
 ]);
diff --git a/util.ts b/util.ts
index 49b96f4..70f17a2 100644
--- a/util.ts
+++ b/util.ts
@@ -6,6 +6,6 @@ const { build, run } = Deno;
 export function xrun(opts: Deno.RunOptions): Deno.Process {
   return run({
     ...opts,
-    args: build.os === "win" ? ["cmd.exe", "/c", ...opts.args] : opts.args
+    cmd: build.os === "win" ? ["cmd.exe", "/c", ...opts.cmd] : opts.cmd
   });
 }