[Performance] Memoize isWsl

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

@@ -393,3 +393,26 @@ describe('readStdinString', () => {
     await expect(got).rejects.toThrow('Stdin input exceeded the maximum allowed size.')
   })
 })
+
+describe('isWsl', () => {
+  test('memoizes the result', async () => {
+    // Given
+    vi.doMock('is-wsl', () => ({default: true}))
+
+    // When
+    const firstCall = await system.isWsl()
+
+    // Then
+    expect(firstCall).toBe(true)
+
+    // Given
+    // We change the mock value. If it's memoized, it should still return the first value.
+    vi.doMock('is-wsl', () => ({default: false}))
+
+    // When
+    const secondCall = await system.isWsl()
+
+    // Then
+    expect(secondCall).toBe(true)
+  })
+})

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

@@ -351,14 +351,18 @@ 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
+  return (memoizedIsWsl ??= import('is-wsl').then((wsl) => wsl.default))
 }
 
 /**