Use recommended ESLint rules and fix all issues

Author: lumaxis

.eslintrc.json

@@ -1,5 +1,9 @@
 {
 	"root": true,
+	"extends": [
+		"eslint:recommended",
+		"plugin:@typescript-eslint/recommended"
+	],
 	"parser": "@typescript-eslint/parser",
 	"parserOptions": {
 		"ecmaVersion": 6,

src/extension.ts

@@ -1,7 +1,7 @@
 import { commands, env, ExtensionContext } from 'vscode';
 import { generateSnippet } from './lib/textHelpers';
 
-export function activate(context: ExtensionContext) {
+export function activate(context: ExtensionContext): void {
 	context.subscriptions.push(
 		commands.registerTextEditorCommand('snippet-copy.copySnippet', async (editor) => {
 			const snippet = generateSnippet(editor.document, editor.selections, false);
@@ -17,5 +17,3 @@ export function activate(context: ExtensionContext) {
 		})
 	);
 }
-
-export function deactivate() { }

src/lib/textHelpers.ts

@@ -3,7 +3,7 @@ import { contentOfLinesWithAdjustedIndentation, endOfLineCharacter, languageId,
 import { lineIndexesForSelection } from "./selectionHelpers";
 
 export function generateSnippet(document: TextDocument, selections: Selection[], markdownCodeBlock = false): string {
-	let texts: string[] = [];
+	const texts: string[] = [];
 	selections.forEach(selection => {
 		texts.push(generateCopyableText(document, selection));
 	});
@@ -19,7 +19,7 @@ export function generateSnippet(document: TextDocument, selections: Selection[],
 	return snippet;
 }
 
-export function generateCopyableText(document: TextDocument, selection: Selection) {
+export function generateCopyableText(document: TextDocument, selection: Selection): string {
 	const lineIndexes = lineIndexesForSelection(selection);
 
 	// Remove last line's index if there's no selected text on that line

src/test/suite/lib/documentHelpers.test.ts

@@ -51,7 +51,7 @@ describe('Document Helpers', function () {
 			const uri = vscode.Uri.file(
 				path.join(__dirname + fixturesPath + 'crlf-ruby-example.rb')
 			);
-			let crlfDocument = await vscode.workspace.openTextDocument(uri);
+			const crlfDocument = await vscode.workspace.openTextDocument(uri);
 
 			assert.equal(contentOfLinesWithAdjustedIndentation(crlfDocument, [1, 2, 3], 2), 'def polish\r\n  puts "Polishing"\r\nend');
 		});