refactor: add write-types-export script

package.json

@@ -65,7 +65,8 @@
     "fmt:check": "prettier --check .",
     "build:rules": "node tools/build-rules.js",
     "build:update-rules-docs": "node tools/update-rules-docs.js",
-    "build": "npm run build:rules && tsc && npm run build:update-rules-docs",
+    "build:write-types-export": "node tools/write-types-export.js",
+    "build": "npm run build:rules && tsc && npm run build:update-rules-docs && npm run build:write-types-export",
     "build:readme": "node tools/update-readme.js",
     "prepare": "npm run build",
     "test": "c8 mocha \"tests/**/*.test.js\" --timeout 30000",

tools/write-types-export.js

@@ -0,0 +1,29 @@
+/**
+ * @fileoverview Adds a re-export of types to dist's index.d.ts file.
+ *
+ * Usage:
+ *  node tools/write-types-export.js
+ *
+ * @author Josh Goldberg
+ */
+
+//-----------------------------------------------------------------------------
+// Imports
+//-----------------------------------------------------------------------------
+
+import fs from "node:fs/promises";
+
+//-----------------------------------------------------------------------------
+// Main
+//-----------------------------------------------------------------------------
+
+const distIndexFile = "dist/esm/index.d.ts";
+
+await fs.writeFile(
+	distIndexFile,
+	[
+		await fs.readFile(distIndexFile, "utf-8"),
+		`export type * from "./types.d.ts";`,
+		"",
+	].join("\n"),
+);