From a7a0c545942f0df33ddac32e6df92e4de13ce24d Mon Sep 17 00:00:00 2001
From: Trevor Burnham <trevorburnham@gmail.com>
Date: Mon, 11 Aug 2025 17:46:37 -0400
Subject: [PATCH] adding ESM type declarations

Fixes #267

When consumers use `"type": "module"` with `"module": "node16"` and
`"moduleResolution": "node16"`, the `export default` declaration in
`memoize-one.d.ts` is considered invalid because those types are
interpreted strictly as CommonJS.

The solution here is to create a separate type declaration file called
`memoize-one.d.mts` with the same contents. The `.mts` extension is the
key here, since it allows the `export default` to be interpreted
correctly as ESM.

I've also added an `exports` declaration to the `package.json` to point ESM-aware consumers to the correct types.

Since all existing code and types are the same, this change should be fully backward-compatible.
---
 .prettierignore |  3 ++-
 package.json    | 14 +++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/.prettierignore b/.prettierignore
index 6fd10a4..85cb8a2 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -1 +1,2 @@
-/node_modules/*
\ No newline at end of file
+/node_modules/*
+/dist
diff --git a/package.json b/package.json
index e57b6d2..109e468 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,18 @@
   "main": "dist/memoize-one.cjs.js",
   "types": "dist/memoize-one.d.ts",
   "module": "dist/memoize-one.esm.js",
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/memoize-one.d.mts",
+        "default": "./dist/memoize-one.esm.js"
+      },
+      "require": {
+        "types": "./dist/memoize-one.d.ts",
+        "default": "./dist/memoize-one.cjs.js"
+      }
+    }
+  },
   "sideEffects": false,
   "files": [
     "/dist",
@@ -96,7 +108,7 @@
     "build": "yarn build:clean && yarn build:dist && yarn build:typescript && yarn build:flow",
     "build:clean": "yarn rimraf dist",
     "build:dist": "yarn rollup -c",
-    "build:typescript": "yarn tsc ./src/memoize-one.ts --emitDeclarationOnly --declaration --outDir ./dist",
+    "build:typescript": "yarn tsc ./src/memoize-one.ts --emitDeclarationOnly --declaration --outDir ./dist && cp ./dist/memoize-one.d.ts ./dist/memoize-one.d.mts",
     "build:flow": "cp src/memoize-one.js.flow dist/memoize-one.cjs.js.flow",
     "perf": "yarn ts-node ./benchmarks/shallow-equal.ts",
     "perf:library-comparison": "yarn build && node ./benchmarks/library-comparison.js",