feat(require-types): add new rule

README.md

@@ -130,6 +130,7 @@ The default settings don't conflict, and Prettier plugins can quickly fix up ord
 | [require-files](docs/rules/require-files.md)                           | Requires the `files` property to be present.                                                      |    |    |    |    |
 | [require-keywords](docs/rules/require-keywords.md)                     | Requires the `keywords` property to be present.                                                   |    |    |    |    |
 | [require-name](docs/rules/require-name.md)                             | Requires the `name` property to be present.                                                       | ✅  |    |    |    |
+| [require-types](docs/rules/require-types.md)                           | Requires the `types` property to be present.                                                      |    |    |    |    |
 | [require-version](docs/rules/require-version.md)                       | Requires the `version` property to be present.                                                    | ✅  |    |    |    |
 | [sort-collections](docs/rules/sort-collections.md)                     | Dependencies, scripts, and configuration values must be declared in alphabetical order.           | ✅  | 🔧 |    |    |
 | [unique-dependencies](docs/rules/unique-dependencies.md)               | Checks a dependency isn't specified more than once (i.e. in `dependencies` and `devDependencies`) | ✅  |    | 💡 |    |

docs/rules/require-types.md

@@ -0,0 +1,27 @@
+# require-types
+
+<!-- end auto-generated rule header -->
+
+This rule checks for the existence of the `"types"` property in a package.json,
+and reports a violation if it doesn't exist.
+
+Example of **incorrect** code for this rule:
+
+```json
+{
+	"name": "Thee Silver Mt. Zion",
+	"version": "13.0.0"
+}
+```
+
+Example of **correct** code for this rule:
+
+```json
+{
+	"name": "Thee Silver Mt. Zion",
+	"version": "13.0.0",
+	"types": "./index.d.ts"
+}
+```
+
+See [TypeScript Handbook > Publishing](https://www.typescriptlang.org/docs/handbook/declaration-files/publishing.html) for more information on publishing package types.

src/rules/require-properties.ts

@@ -9,6 +9,7 @@ const properties = [
 	["files", false],
 	["keywords", false],
 	["name", true],
+	["types", false],
 	["version", true],
 	// TODO: More to come!
 ] satisfies [string, boolean][];

src/tests/rules/require-types.test.ts

@@ -0,0 +1,47 @@
+import { rules } from "../../rules/require-properties.js";
+import { ruleTester } from "./ruleTester.js";
+
+ruleTester.run("require-types", rules["require-types"], {
+	invalid: [
+		{
+			code: "{}",
+			errors: [
+				{
+					data: { property: "types" },
+					line: 1,
+					messageId: "missing",
+				},
+			],
+		},
+		{
+			code: `{
+            "version": "1.0.0"
+            }
+            `,
+			errors: [
+				{
+					data: { property: "types" },
+					line: 1,
+					messageId: "missing",
+				},
+			],
+		},
+		{
+			code: `{
+            "author": "Jessica Moss",
+            "bin": {
+                "types": "./index.js"
+            }
+            }
+            `,
+			errors: [
+				{
+					data: { property: "types" },
+					line: 1,
+					messageId: "missing",
+				},
+			],
+		},
+	],
+	valid: [`{ "types": "./index.d.ts" }`],
+});