Fix duplicated check for WSL

src/browser/browser.ts

@@ -7,8 +7,11 @@ export interface BrowserOptions {
 }
 
 export abstract class Browser {
-  abstract kind: BrowserKind
-  abstract protocol: BrowserProtocol
+  static readonly kind: BrowserKind
+  static readonly protocol: BrowserProtocol
+
+  // ---
+
   purpose: BrowserPurpose
 
   constructor(opts: BrowserOptions) {

src/browser/browsers/chrome-cdp.ts

@@ -1,6 +1,6 @@
 import { Browser } from '../browser'
 
 export class ChromeCdpBrowser extends Browser {
-  kind = 'chrome' as const
-  protocol = 'cdp' as const
+  static readonly kind = 'chrome' as const
+  static readonly protocol = 'cdp' as const
 }

src/browser/browsers/chrome.ts

@@ -1,6 +1,6 @@
 import { Browser } from '../browser'
 
 export class ChromeBrowser extends Browser {
-  kind = 'chrome' as const
-  protocol = 'webdriver-bidi' as const
+  static readonly kind = 'chrome' as const
+  static readonly protocol = 'webdriver-bidi' as const
 }

src/browser/browsers/firefox.ts

@@ -1,6 +1,6 @@
 import { Browser } from '../browser'
 
 export class FirefoxBrowser extends Browser {
-  kind = 'firefox' as const
-  protocol = 'webdriver-bidi' as const
+  static readonly kind = 'firefox' as const
+  static readonly protocol = 'webdriver-bidi' as const
 }

src/utils/wsl.ts

@@ -1,7 +1,8 @@
 import { execFile, spawnSync } from 'node:child_process'
-import { readFileSync } from 'node:fs'
+import fs from 'node:fs'
+import { debug } from './debug'
 
-let isWsl: number | undefined
+let isWsl: number | Promise<number> | undefined
 
 export const resolveWSLPathToHost = async (path: string): Promise<string> =>
   await new Promise<string>((res, rej) => {
@@ -30,31 +31,41 @@ export const resolveWindowsEnvSync = (key: string): string | undefined => {
   return ret.startsWith(`${key}=`) ? ret.slice(key.length + 1) : undefined
 }
 
+const wsl2VerMatcher = /microsoft-standard-wsl2/i
+
 export const isWSL = async (): Promise<number> => {
   if (isWsl === undefined) {
-    if ((await import('is-wsl')).default) {
-      // Detect whether WSL version is 2
-      // https://github.com/microsoft/WSL/issues/4555#issuecomment-700213318
-      const isWSL2 = (() => {
-        if (process.env.WSL_DISTRO_NAME && process.env.WSL_INTEROP) return true
-
-        try {
-          const verStr = readFileSync('/proc/version', 'utf8').toLowerCase()
-          if (verStr.includes('microsoft-standard-wsl2')) return true
-
-          const gccMatched = verStr.match(/gcc[^,]+?(\d+)\.\d+\.\d+/)
-          if (gccMatched && Number.parseInt(gccMatched[1], 10) >= 8) return true
-        } catch {
-          // no ops
-        }
-      })()
-
-      isWsl = isWSL2 ? 2 : 1
-    } else {
-      isWsl = 0
-    }
+    isWsl = (async () => {
+      if ((await import('is-wsl')).default) {
+        // Detect whether WSL version is 2
+        // https://github.com/microsoft/WSL/issues/4555#issuecomment-700213318
+        const isWSL2 = await (async () => {
+          if (process.env.WSL_DISTRO_NAME && process.env.WSL_INTEROP)
+            return true
+
+          try {
+            const verStr = await fs.promises.readFile('/proc/version', 'utf8')
+            if (wsl2VerMatcher.test(verStr)) return true
+
+            const gccMatched = verStr.match(/gcc[^,]+?(\d+)\.\d+\.\d+/)
+            if (gccMatched && Number.parseInt(gccMatched[1], 10) >= 8)
+              return true
+          } catch {
+            // no ops
+          }
+        })()
+
+        const wslVersion = isWSL2 ? 2 : 1
+        debug('Detected WSL version: %s', wslVersion)
+
+        return wslVersion
+      } else {
+        return 0
+      }
+    })().then((correctedIsWsl) => (isWsl = correctedIsWsl))
   }
-  return isWsl
+
+  return await isWsl
 }
 
 export const isChromeInWSLHost = async (chromePath: string | undefined) =>