fix: check property existence before patching (#52)

Co-authored-by: JounQin <admin@1stg.me>

.changeset/dirty-jobs-live.md

@@ -0,0 +1,5 @@
+---
+"sh-syntax": patch
+---
+
+fix: check property existence before patching

package.json

@@ -71,7 +71,7 @@
     "lint": "run-p lint:*",
     "lint:es": "eslint . --cache -f friendly --max-warnings 10",
     "lint:tsc": "tsc --noEmit",
-    "prepare": "simple-git-hooks",
+    "prepare": "simple-git-hooks || exit 0",
     "prerelease": "pnpm build",
     "release": "changeset publish",
     "test": "vitest run --coverage",

src/shim.ts

@@ -1,11 +1,21 @@
+/* eslint-disable @typescript-eslint/no-unnecessary-condition */
+
 import { randomFillSync } from 'node:crypto'
 import _fs from 'node:fs'
 import { performance } from 'node:perf_hooks'
 
-globalThis.fs = _fs
-globalThis.crypto = {
+if (!globalThis.fs) {
+  globalThis.fs = _fs
+}
+
+if (!globalThis.crypto) {
+  globalThis.crypto = {
+    // @ts-expect-error
+    getRandomValues: randomFillSync,
+  }
+}
+
+if (!globalThis.performance) {
   // @ts-expect-error
-  getRandomValues: randomFillSync,
+  globalThis.performance = performance
 }
-// @ts-expect-error
-globalThis.performance = performance