Add the troubleshooting link to the exception messages (#345)

* Add the troubleshooting link to the exception messages

* Use a constant

lib/tools/apk-utils.js

@@ -10,6 +10,9 @@ import os from 'os';
 
 let apkUtilsMethods = {};
 
+const ACTIVITIES_TROUBLESHOOTING_LINK =
+  'https://github.com/appium/appium/blob/master/docs/en/writing-running-appium/android/activity-startup.md';
+
 /**
  * Check whether the particular package is present on the device under test.
  *
@@ -40,9 +43,15 @@ apkUtilsMethods.startUri = async function (uri, pkg) {
   if (!uri || !pkg) {
     throw new Error("URI and package arguments are required");
   }
+
+  const args = [
+    "am", "start",
+    "-W",
+    "-a", "android.intent.action.VIEW",
+    "-d", uri.replace(/&/g, '\\&'),
+    pkg,
+  ];
   try {
-    let args = ["am", "start", "-W", "-a", "android.intent.action.VIEW", "-d",
-                uri.replace(/&/g, '\\&'), pkg];
     const res = await this.shell(args);
     if (res.toLowerCase().includes('unable to resolve intent')) {
       throw new Error(res);
@@ -122,7 +131,9 @@ apkUtilsMethods.startApp = async function (startAppOptions = {}) {
     }
     return stdout;
   } catch (e) {
-    throw new Error(`Cannot start the '${startAppOptions.pkg}' application. Original error: ${e.message}`);
+    throw new Error(`Cannot start the '${startAppOptions.pkg}' application. ` +
+      `Visit ${ACTIVITIES_TROUBLESHOOTING_LINK} for troubleshooting. ` +
+      `Original error: ${e.message}`);
   }
 };
 
@@ -237,7 +248,8 @@ apkUtilsMethods.waitForActivityOrNot = async function (pkg, activity, waitForSto
     }
     log.debug('Incorrect package and activity. Retrying.');
     /* jshint ignore:start */
-    throw new Error(`${possibleActivityNames.map((name) => `'${name}'`).join(' or ')} never ${waitForStop ? 'stopped' : 'started'}`);
+    throw new Error(`${possibleActivityNames.map((name) => `'${name}'`).join(' or ')} never ${waitForStop ? 'stopped' : 'started'}. ` +
+      `Visit ${ACTIVITIES_TROUBLESHOOTING_LINK} for troubleshooting`);
     /* jshint ignore:end */
   });
 };