Fix eslint warnings and small clean ups (#339)

fs/README.md

@@ -31,7 +31,7 @@ ensureDir("./bar"); // returns a promise
 ensureDirSync("./ensureDirSync"); // void
 ```
 
-### ensure_file
+### ensureFile
 
 Ensures that the file exists.
 If the file that is requested to be created is in directories

prettier/main_test.ts

@@ -107,7 +107,8 @@ test(async function testPrettierOptions() {
   const file2 = join(testdata, "opts", "2.ts");
   const file3 = join(testdata, "opts", "3.md");
 
-  const getSourceCode = async f => decoder.decode(await Deno.readFile(f));
+  const getSourceCode = async (f: string): Promise<string> =>
+    decoder.decode(await Deno.readFile(f));
 
   await run([...cmd, "--no-semi", file0]);
   assertEquals(

testing/main.ts

@@ -1,7 +1,7 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 import { runTests } from "./mod.ts";
 
-async function main() {
+async function main(): Promise<void> {
   // Testing entire test suite serially
   await runTests();
 }

toml/parser.ts

@@ -1,5 +1,6 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 import { existsSync } from "../fs/exists.ts";
+import { readFileStrSync } from "../fs/read_file_str.ts";
 import { deepAssign } from "../util/deep_assign.ts";
 import { pad } from "../strings/pad.ts";
 
@@ -542,7 +543,6 @@ export function parseFile(filePath: string): object {
   if (!existsSync(filePath)) {
     throw new Error("File not found");
   }
-  const decoder = new TextDecoder();
-  const strFile = decoder.decode(Deno.readFileSync(filePath));
+  const strFile = readFileStrSync(filePath);
   return parse(strFile);
 }