fix: proxy request to the espresso server with nativeWebScreenshot (#978)

Author: KazuCocoa

lib/commands/screenshot.js

@@ -75,3 +75,21 @@ export async function mobileScreenshots (opts = {}) {
   }
   return infos;
 }
+
+/**
+ * Return the base 64 encoded screenshot data.
+ * This method is called only when `appium:nativeWebScreenshot` is enabled
+ * to avoid proxying requests to the chromedriver.
+ * Without `appium:nativeWebScreenshot` or disabled, espresso driver
+ * proxies screenshot endpoint requests to the espresso server directly.
+ *
+ * @this {import('../driver').EspressoDriver}
+ * @returns {Promise<String>}
+ */
+export async function getScreenshot() {
+  return String(
+    await /** @type {import('../espresso-runner').EspressoRunner} */ (
+      this.espresso
+    ).jwproxy.command('/screenshot', 'GET')
+  );
+}

lib/driver.ts

@@ -735,6 +735,7 @@ export class EspressoDriver extends AndroidDriver implements ExternalDriver<
   mobileStartService = servicesCmds.mobileStartService;
   mobileStopService = servicesCmds.mobileStopService;
 
+  getScreenshot = screenshotCmds.getScreenshot;
   mobileScreenshots = screenshotCmds.mobileScreenshots;
 
   mobileRegisterIdlingResources = idlingResourcesCmds.mobileRegisterIdlingResources;