[Performance] Memoize isWsl result

packages/cli-kit/src/public/node/system.test.ts

@@ -353,6 +353,32 @@ describe('isStdinPiped', () => {
   })
 })
 
+describe('isWsl', () => {
+  test('memoizes the result', async () => {
+    // When
+    const result1 = system.isWsl()
+    const result2 = system.isWsl()
+
+    // Then
+    expect(result1).toBe(result2)
+    await expect(result1).resolves.toBeTypeOf('boolean')
+  })
+
+  test('clears the cache when reset', async () => {
+    // Given
+    const result1 = system.isWsl()
+    system._resetIsWsl()
+
+    // When
+    const result2 = system.isWsl()
+
+    // Then
+    expect(result1).not.toBe(result2)
+    await expect(result1).resolves.toBeTypeOf('boolean')
+    await expect(result2).resolves.toBeTypeOf('boolean')
+  })
+})
+
 describe('readStdinString', () => {
   test('returns undefined when stdin is not piped', async () => {
     // Given

packages/cli-kit/src/public/node/system.ts

@@ -354,14 +354,26 @@ export function isCI(): boolean {
   return isTruthy(process.env.CI)
 }
 
+/**
+ * Memoized value for the WSL check.
+ */
+let memoizedIsWsl: Promise<boolean> | undefined
+
 /**
  * Check if the current environment is a WSL environment.
  *
  * @returns True if the current environment is a WSL environment.
  */
-export async function isWsl(): Promise<boolean> {
-  const wsl = await import('is-wsl')
-  return wsl.default
+export function isWsl(): Promise<boolean> {
+  return (memoizedIsWsl ??= import('is-wsl').then((module) => module.default))
+}
+
+/**
+ * Resets the memoized value for the WSL check.
+ * This is used for testing purposes.
+ */
+export function _resetIsWsl() {
+  memoizedIsWsl = undefined
 }
 
 /**