update entry point for isTestRunner

package.json

@@ -19,6 +19,13 @@
   "main": "dist/cjs/index.js",
   "module": "dist/esm/index.js",
   "types": "dist/ts/index.d.ts",
+  "exports": {
+    "./is-test-runner": {
+      "import": "./src/is-test-runner/is-test-runner.mjs",
+      "browser": "./src/is-test-runner/is-test-runner.mjs",
+      "require": "./src/is-test-runner/is-test-runner.cjs"
+    }
+  },
   "files": [
     "bin",
     "dist/**/*",
@@ -30,8 +37,8 @@
   "scripts": {
     "clean": "rimraf ./dist",
     "buildBabel": "concurrently \"yarn buildBabel:cjs\" \"yarn buildBabel:esm\"",
-    "buildBabel:cjs": "babel ./src -d ./dist/cjs --extensions \".js,.jsx,.ts,.tsx\"",
-    "buildBabel:esm": "babel ./src -d ./dist/esm --env-name esm --extensions \".js,.jsx,.ts,.tsx\"",
+    "buildBabel:cjs": "babel ./src -d ./dist/cjs --extensions \".js,.jsx,.ts,.tsx\" --copy-files src/is-test-runner.js",
+    "buildBabel:esm": "babel ./src -d ./dist/esm --env-name esm --extensions \".js,.jsx,.ts,.tsx\" --copy-files src/is-test-runner.js",
     "buildTsc": "tsc --declaration --emitDeclarationOnly --outDir ./dist/ts",
     "prebuild": "yarn clean",
     "build": "concurrently \"yarn buildBabel\" \"yarn buildTsc\"",

src/is-test-runner/is-test-runner.cjs

@@ -0,0 +1,6 @@
+/**
+ * Returns whether the story is rendering inside of the Storybook test runner.
+ */
+export function isTestRunner() {
+  return process?.env?.STORYBOOK_TEST_RUNNER === 'true';
+}

src/is-test-runner.ts → src/is-test-runner/is-test-runner.mjs

@@ -2,12 +2,9 @@
  * Returns whether the story is rendering inside of the Storybook test runner.
  */
 export function isTestRunner() {
-  const isTestRunnerInNode = process?.env?.STORYBOOK_TEST_RUNNER === 'true';
-  const isTestRunnerInBrowser = !!(
+  return!!(
     typeof window !== 'undefined' &&
     window &&
     window.navigator.userAgent.match(/StorybookTestRunner/)
   );
-
-  return isTestRunnerInNode || isTestRunnerInBrowser;
 }