InvalidArgumentException: invalid argument: Unsupported locator strategy: -custom error with Appium using Selenium ChromeDriver and Chrome - selenium

Question

I'm trying to run the test.ai plugin for appium (https://github.com/testdotai/appium-classifier-plugin). It has a custom locator strategy. I set up appium (version 1.13.0, also tried downgrading to 1.9.2-beta.2) and did:
'npm install -g test-ai-classifier'
it was installed, as shown:
https://i.stack.imgur.com/fwtkt.png
I then wrote a simple test to check if everything is set up correctly:
import io.appium.java_client.AppiumDriver;
import io.appium.java_client.android.AndroidDriver;
import io.appium.java_client.remote.MobileCapabilityType;
import io.appium.java_client.MobileBy;
import io.appium.java_client.MobileElement;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import org.junit.Before;
import org.junit.After;
import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.remote.DesiredCapabilities;
public class TestClass {
private AppiumDriver driver;
private By cart = MobileBy.custom("cart");
#Before
public void setUp() throws MalformedURLException {
DesiredCapabilities capabilities = new DesiredCapabilities();
capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "Android");
capabilities.setCapability(MobileCapabilityType.PLATFORM_VERSION, "9");
capabilities.setCapability(MobileCapabilityType.DEVICE_NAME, "NB1GAD17B1504154");
capabilities.setCapability(MobileCapabilityType.BROWSER_NAME, "Chrome");
HashMap<String, String> customFindModules = new HashMap<>();
customFindModules.put("ai", "test-ai-classifier");
capabilities.setCapability("customFindModules", customFindModules);
capabilities.setCapability("shouldUseCompactResponses", false);
driver = new AndroidDriver(new URL("http://localhost:4723/wd/hub"), capabilities);
}
#After
public void tearDown(){
}
#Test
public void testMethod(){
goToWebsite(driver);
openCartUseAi(driver);
}
public void goToWebsite(AppiumDriver driver){
driver.get("https://www.ebay.com/");
}
public void openCartUseAi(AppiumDriver driver){
driver.findElement(cart).click();
}
}
This causes the following error when ran:
/usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/java -ea -Didea.test.cyclic.buffer.size=1048576 -javaagent:/home/piotrek/intellij/ideaIC-2019.1.2/idea-IC-191.7141.44/lib/idea_rt.jar=46303:/home/piotrek/intellij/ideaIC-2019.1.2/idea-IC-191.7141.44/bin -Dfile.encoding=UTF-8 -classpath /home/piotrek/intellij/ideaIC-2019.1.2/idea-IC-191.7141.44/lib/idea_rt.jar:/home/piotrek/intellij/ideaIC-2019.1.2/idea-IC-191.7141.44/plugins/junit/lib/junit-rt.jar:/home/piotrek/intellij/ideaIC-2019.1.2/idea-IC-191.7141.44/plugins/junit/lib/junit5-rt.jar:/home/piotrek/IdeaProjects/appiumTestMVN/target/test-classes:/home/piotrek/Downloads/selenium-server-standalone-3.141.59.jar:/home/piotrek/.m2/repository/io/appium/java-client/7.0.0/java-client-7.0.0.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-java/3.141.59/selenium-java-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-chrome-driver/3.141.59/selenium-chrome-driver-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-edge-driver/3.141.59/selenium-edge-driver-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-firefox-driver/3.141.59/selenium-firefox-driver-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-ie-driver/3.141.59/selenium-ie-driver-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-opera-driver/3.141.59/selenium-opera-driver-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-remote-driver/3.141.59/selenium-remote-driver-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-safari-driver/3.141.59/selenium-safari-driver-3.141.59.jar:/home/piotrek/.m2/repository/net/bytebuddy/byte-buddy/1.8.15/byte-buddy-1.8.15.jar:/home/piotrek/.m2/repository/org/apache/commons/commons-exec/1.3/commons-exec-1.3.jar:/home/piotrek/.m2/repository/com/google/guava/guava/25.0-jre/guava-25.0-jre.jar:/home/piotrek/.m2/repository/com/google/code/findbugs/jsr305/1.3.9/jsr305-1.3.9.jar:/home/piotrek/.m2/repository/org/checkerframework/checker-compat-qual/2.0.0/checker-compat-qual-2.0.0.jar:/home/piotrek/.m2/repository/com/google/errorprone/error_prone_annotations/2.1.3/error_prone_annotations-2.1.3.jar:/home/piotrek/.m2/repository/com/google/j2objc/j2objc-annotations/1.1/j2objc-annotations-1.1.jar:/home/piotrek/.m2/repository/org/codehaus/mojo/animal-sniffer-annotations/1.14/animal-sniffer-annotations-1.14.jar:/home/piotrek/.m2/repository/com/squareup/okhttp3/okhttp/3.11.0/okhttp-3.11.0.jar:/home/piotrek/.m2/repository/com/squareup/okio/okio/1.14.0/okio-1.14.0.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-support/3.141.59/selenium-support-3.141.59.jar:/home/piotrek/.m2/repository/org/seleniumhq/selenium/selenium-api/3.141.59/selenium-api-3.141.59.jar:/home/piotrek/.m2/repository/com/google/code/gson/gson/2.8.5/gson-2.8.5.jar:/home/piotrek/.m2/repository/org/apache/httpcomponents/httpclient/4.5.6/httpclient-4.5.6.jar:/home/piotrek/.m2/repository/org/apache/httpcomponents/httpcore/4.4.10/httpcore-4.4.10.jar:/home/piotrek/.m2/repository/commons-logging/commons-logging/1.2/commons-logging-1.2.jar:/home/piotrek/.m2/repository/commons-codec/commons-codec/1.10/commons-codec-1.10.jar:/home/piotrek/.m2/repository/cglib/cglib/3.2.8/cglib-3.2.8.jar:/home/piotrek/.m2/repository/org/ow2/asm/asm/6.2.1/asm-6.2.1.jar:/home/piotrek/.m2/repository/org/apache/ant/ant/1.10.3/ant-1.10.3.jar:/home/piotrek/.m2/repository/org/apache/ant/ant-launcher/1.10.3/ant-launcher-1.10.3.jar:/home/piotrek/.m2/repository/commons-validator/commons-validator/1.6/commons-validator-1.6.jar:/home/piotrek/.m2/repository/commons-beanutils/commons-beanutils/1.9.2/commons-beanutils-1.9.2.jar:/home/piotrek/.m2/repository/commons-digester/commons-digester/1.8.1/commons-digester-1.8.1.jar:/home/piotrek/.m2/repository/commons-collections/commons-collections/3.2.2/commons-collections-3.2.2.jar:/home/piotrek/.m2/repository/org/apache/commons/commons-lang3/3.8/commons-lang3-3.8.jar:/home/piotrek/.m2/repository/commons-io/commons-io/2.6/commons-io-2.6.jar:/home/piotrek/.m2/repository/org/springframework/spring-context/5.1.0.RELEASE/spring-context-5.1.0.RELEASE.jar:/home/piotrek/.m2/repository/org/springframework/spring-aop/5.1.0.RELEASE/spring-aop-5.1.0.RELEASE.jar:/home/piotrek/.m2/repository/org/springframework/spring-beans/5.1.0.RELEASE/spring-beans-5.1.0.RELEASE.jar:/home/piotrek/.m2/repository/org/springframework/spring-core/5.1.0.RELEASE/spring-core-5.1.0.RELEASE.jar:/home/piotrek/.m2/repository/org/springframework/spring-jcl/5.1.0.RELEASE/spring-jcl-5.1.0.RELEASE.jar:/home/piotrek/.m2/repository/org/springframework/spring-expression/5.1.0.RELEASE/spring-expression-5.1.0.RELEASE.jar:/home/piotrek/.m2/repository/org/aspectj/aspectjweaver/1.9.1/aspectjweaver-1.9.1.jar:/home/piotrek/.m2/repository/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar:/home/piotrek/.m2/repository/junit/junit/4.12/junit-4.12.jar:/home/piotrek/.m2/repository/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 TestClass,testMethod
Jun 07, 2019 1:43:44 PM io.appium.java_client.remote.AppiumCommandExecutor$1 lambda$0
INFO: Detected dialect: W3C
org.openqa.selenium.InvalidArgumentException: invalid argument: Unsupported locator strategy: -custom
(Session info: chrome=74.0.3729.157)
(Driver info: chromedriver=74.0.3729.6 (255758eccf3d244491b8a1317aa76e1ce10d57e9-refs/branch-heads/3729#{#29}),platform=Linux 5.0.0-15-generic x86_64)
Build info: version: '3.141.59', revision: 'e82be7d358', time: '2018-11-14T08:25:53'
System info: host: 'piotrek-VirtualBox', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'amd64', os.version: '5.0.0-15-generic', java.version: '11.0.3'
Driver info: io.appium.java_client.android.AndroidDriver
Capabilities {browserName: Chrome, customFindModules: {ai: test-ai-classifier}, databaseEnabled: false, desired: {browserName: Chrome, customFindModules: {ai: test-ai-classifier}, deviceName: NB1GAD17B1504154, platformName: android, platformVersion: 9, shouldUseCompactResponses: false}, deviceManufacturer: HMD Global, deviceModel: TA-1004, deviceName: NB1GAD17B1504154, deviceScreenSize: 1440x2560, deviceUDID: NB1GAD17B1504154, javascriptEnabled: true, locationContextEnabled: false, networkConnectionEnabled: true, platform: LINUX, platformName: Android, platformVersion: 9, shouldUseCompactResponses: false, takesScreenshot: true, warnings: {}, webStorageEnabled: false}
Session ID: 6cb83c3b-3405-483a-8dc3-21eec62b4676
*** Element info: {Using=-custom, value=ai:cart}
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:187)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:122)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:49)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158)
at io.appium.java_client.remote.AppiumCommandExecutor.execute(AppiumCommandExecutor.java:239)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:552)
at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:42)
at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:1)
at io.appium.java_client.android.AndroidDriver.execute(AndroidDriver.java:1)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:323)
at io.appium.java_client.DefaultGenericMobileDriver.findElement(DefaultGenericMobileDriver.java:62)
at io.appium.java_client.AppiumDriver.findElement(AppiumDriver.java:1)
at io.appium.java_client.android.AndroidDriver.findElement(AndroidDriver.java:1)
at io.appium.java_client.FindsByCustom.findElementByCustom(FindsByCustom.java:38)
at TestClass.openCartUseAi(TestClass.java:64)
at TestClass.testMethod(TestClass.java:49)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Process finished with exit code 255
Can anyone tell me what I'm doing wrong? When rewriting this test to not use the plugin, everything works fine, so Appium is set up correctly.
I had a look at this doc, but still can't see what I'm missing: http://appium.io/docs/en/advanced-concepts/element-finding-plugins/
Thank You in advance for your help!
PS not sure if this is relevant, but I'm using an Ubuntu virtual machine for this

Answer 1

This error message...
org.openqa.selenium.InvalidArgumentException: invalid argument: Unsupported locator strategy: -custom
...implies that the ChromeDriver was unable to initiate/spawn a new WebBrowser i.e. Chrome Browser session due to an invalid argument within an Unsupported locator strategy.
Your main issue is the incompatibility between the version of the binaries you are using as follows:
You are using chromedriver=2.46
Release Notes of chromedriver=2.46 clearly mentions the following :
Supports Chrome v71-73
You are using chrome=74.0
Release Notes of ChromeDriver v74.0 clearly mentions the following :
Supports Chrome v74
So there is a clear mismatch between ChromeDriver v2.46 and the Chrome Browser v74.0
Solution
Upgrade ChromeDriver to ChromeDriver v75.0 level.
Upgrade Chrome to Chrome v75 level. (as per ChromeDriver v75.0 release notes)
Clean your Project Workspace through your IDE and Rebuild your project with required dependencies only.

Answer 2

Okay, got this figured out myself. Apparently Appium and Test.Ai don't yet support a custom locator strategy on web apps. This only works on native apps for now. Shame they didn't put this info in their documentation :P

Answer 3

Set this capability,
setCapability("chromeOptions", ImmutableMap.of("w3c", false));
On my side got the same issue, I was try out this code it worked smoothly.