Add no-empty-file rule

docs/rules/no-empty-file.md

@@ -0,0 +1,15 @@
+# Disallow empty files.
+
+<!-- More detailed description. Remove this comment. -->
+
+## Fail
+
+```js
+const foo = 'unicorn';
+```
+
+## Pass
+
+```js
+const foo = '🦄';
+```

readme.md

@@ -178,6 +178,7 @@ Each rule has emojis denoting:
 | [no-array-reduce](docs/rules/no-array-reduce.md) | Disallow `Array#reduce()` and `Array#reduceRight()`. | ✅ |  |  |
 | [no-console-spaces](docs/rules/no-console-spaces.md) | Do not use leading/trailing space between `console.log` parameters. | ✅ | 🔧 |  |
 | [no-document-cookie](docs/rules/no-document-cookie.md) | Do not use `document.cookie` directly. | ✅ |  |  |
+| [no-empty-file](docs/rules/no-empty-file.md) | Disallow empty files. |  |  |  |
 | [no-for-loop](docs/rules/no-for-loop.md) | Do not use a `for` loop that can be replaced with a `for-of` loop. | ✅ | 🔧 |  |
 | [no-hex-escape](docs/rules/no-hex-escape.md) | Enforce the use of Unicode escapes instead of hexadecimal escapes. | ✅ | 🔧 |  |
 | [no-instanceof-array](docs/rules/no-instanceof-array.md) | Require `Array.isArray()` instead of `instanceof Array`. | ✅ | 🔧 |  |

rules/no-empty-file.js

@@ -0,0 +1,50 @@
+'use strict';
+const MESSAGE_ID = 'no-empty-file';
+const messages = {
+	[MESSAGE_ID]: 'Prefer `{{replacement}}` over `{{value}}`.',
+};
+
+/** @param {import('eslint').Rule.RuleContext} context */
+const create = () => ({
+	Program(node) {
+		const problem = {
+			node,
+			messageId: MESSAGE_ID,
+			data: {
+				value: 'unicorn',
+				replacement: '🦄',
+			},
+		};
+
+		if (node.body.length === 1 && node.body[0].directive === 'use strict') {
+			return problem;
+		}
+
+		let fileIsEmpty = true;
+
+		for (const child of node.body) {
+			if (child.type !== 'EmptyStatement') {
+				fileIsEmpty = false;
+				break;
+			}
+		}
+
+		if (fileIsEmpty) {
+			return problem;
+		}
+	},
+});
+
+const schema = [];
+
+module.exports = {
+	create,
+	meta: {
+		type: 'suggestion',
+		docs: {
+			description: 'Disallow empty files.',
+		},
+		schema,
+		messages,
+	},
+};

test/no-empty-file.mjs

@@ -0,0 +1,29 @@
+import outdent from 'outdent';
+import {getTester} from './utils/test.mjs';
+
+const {test} = getTester(import.meta);
+const space = '';
+const tab = '	';
+
+test.snapshot({
+	valid: [
+		'const foo = "🦄";',
+	],
+	invalid: [
+		'',
+		space,
+		tab,
+		'\n',
+		'\r',
+		'\r\n',
+		outdent`
+
+
+		`,
+		'// comment',
+		'/* comment */',
+		'\'use strict\';',
+		';',
+		';;',
+	],
+});