Update devDependencies and lint

Author: fregante

index.ts

@@ -355,7 +355,7 @@ collect.set('isTrending', [
 	'https://github.com/trending/unknown',
 ]);
 
-export const isBranches = (url: URL | Location = location): boolean => String(getRepoPath(url)).startsWith('branches') ?? false;
+export const isBranches = (url: URL | Location = location): boolean => String(getRepoPath(url)).startsWith('branches');
 collect.set('isBranches', [
 	'https://github.com/sindresorhus/refined-github/branches',
 ]);

package.json

@@ -33,15 +33,24 @@
 		"envs": [
 			"browser"
 		],
+		"overrides": [
+			{
+				"files": [
+					"*.ts"
+				],
+				"rules": {
+					"@typescript-eslint/no-unnecessary-condition": "error"
+				}
+			}
+		],
 		"rules": {
 			"camelcase": "off",
-			"unicorn/import-index": "off",
-			"import/no-useless-path-segments": "off",
-			"@typescript-eslint/prefer-readonly-parameter-types": "off",
 			"comma-dangle": [
 				"error",
 				"always-multiline"
-			]
+			],
+			"import/no-useless-path-segments": "off",
+			"unicorn/import-index": "off"
 		}
 	},
 	"ava": {
@@ -54,22 +63,21 @@
 		]
 	},
 	"devDependencies": {
-		"@rollup/plugin-json": "^4.0.3",
-		"@rollup/plugin-node-resolve": "^7.1.3",
-		"@rollup/plugin-typescript": "^4.1.1",
+		"@rollup/plugin-json": "^4.1.0",
+		"@rollup/plugin-typescript": "^4.1.2",
 		"@sindresorhus/tsconfig": "^0.7.0",
-		"@types/jsdom": "^16.2.1",
-		"ava": "^3.8.1",
+		"@types/jsdom": "^16.2.3",
+		"ava": "^3.8.2",
 		"esm": "^3.2.25",
 		"github-reserved-names": "^1.1.8",
 		"jsdom": "^16.2.2",
 		"npm-run-all": "^4.1.5",
-		"rollup": "^2.7.6",
-		"rollup-plugin-terser": "^5.3.0",
+		"rollup": "^2.13.1",
+		"rollup-plugin-terser": "^6.1.0",
 		"strip-indent": "^3.0.0",
-		"ts-node": "^8.10.1",
-		"tslib": "^1.11.2",
-		"typescript": "^3.8.3",
-		"xo": "^0.30.0"
+		"ts-node": "^8.10.2",
+		"tslib": "^2.0.0",
+		"typescript": "^3.9.5",
+		"xo": "^0.32.0"
 	}
 }