Add eslint for linting (denoland/deno_std#235)

Original: https://github.com/denoland/deno_std/commit/c0390ade3de4d825423c9f0f5e1aa56ffd509942

4 files changed, 9 insertions, 6 deletions

diff --git a/prettier/main.ts b/prettier/main.ts
index 70c225086..286cba58c 100755
--- a/prettier/main.ts
+++ b/prettier/main.ts
@@ -2,7 +2,7 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 // This script formats the given source files. If the files are omitted, it
 // formats the all files in the repository.
-const { args, platform, readAll, lstat, exit, run, readFile, writeFile } = Deno;
+const { args, readAll, lstat, exit, readFile, writeFile } = Deno;
 import { xrun } from "./util.ts";
 import { parse } from "../flags/mod.ts";
 import { prettier, prettierPlugins } from "./prettier.ts";
@@ -67,7 +67,7 @@ async function getSourceFiles(args: string[]): Promise<string[]> {
 }
 
 // Filters out the files which contains any pattern in the given ignoreList.
-function filterIgnoreList(files: string[], ignoreList: string[]) {
+function filterIgnoreList(files: string[], ignoreList: string[]): string[] {
   return files.filter(path =>
     ignoreList.every(pattern => !path.includes(pattern))
   );
@@ -203,7 +203,7 @@ async function formatSourceFiles(
   exit(0);
 }
 
-async function main(opts) {
+async function main(opts): Promise<void> {
   const { help, ignore, check, _: args } = opts;
 
   if (help) {
diff --git a/prettier/main_test.ts b/prettier/main_test.ts
index 165081e00..b6c0489ee 100644
--- a/prettier/main_test.ts
+++ b/prettier/main_test.ts
@@ -5,7 +5,9 @@ const { readAll } = Deno;
 
 const decoder = new TextDecoder();
 
-async function run(args: string[]) {
+async function run(
+  args: string[]
+): Promise<{ stdout: string; code: number | undefined }> {
   const p = xrun({ args, stdout: "piped" });
 
   const stdout = decoder.decode(await readAll(p.stdout));
@@ -33,7 +35,7 @@ function normalizeOutput(output: string): string {
     .join("\n");
 }
 
-async function clearTestdataChanges() {
+async function clearTestdataChanges(): Promise<void> {
   await xrun({ args: ["git", "checkout", testdata] }).status();
 }
 
diff --git a/prettier/prettier.ts b/prettier/prettier.ts
index 67099c5ca..98f36a78d 100644
--- a/prettier/prettier.ts
+++ b/prettier/prettier.ts
@@ -5,6 +5,7 @@ import "./vendor/parser_babylon.js";
 import "./vendor/parser_markdown.js";
 
 // TODO: provide decent type declarions for these
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
 const { prettier, prettierPlugins } = window as any;
 
 export { prettier, prettierPlugins };
diff --git a/prettier/util.ts b/prettier/util.ts
index 0be583f75..425cbfe96 100644
--- a/prettier/util.ts
+++ b/prettier/util.ts
@@ -2,7 +2,7 @@
 const { platform, run } = Deno;
 
 // Runs a command in cross-platform way
-export function xrun(opts) {
+export function xrun(opts): Deno.Process {
   return run({
     ...opts,
     args: platform.os === "win" ? ["cmd.exe", "/c", ...opts.args] : opts.args