Authentication error to bing service dies silently at UI

Pushing to major as it's a severe usability issue.
People always had problems to get the credentials right.
Validation is critical.

Yes, but we decided to leave it originally because it still worked for existing clients. Probably no longer the case.

I can confirm that the old method does not work anymore. It should be removed with the next release and these problems could be fixed though. It would be good to output a note using hook_update() :)

Could the maintainer have a look at this perhaps and fix it in the .dev release?
This bug makes the module hard to use for new users currently!

In this issue we can do both validations, the api-key and the remote langcode (https://www.drupal.org/node/2256959#comment-10331205).

Done both validations for api key and for languages.
Added tests for not valid api key.
Tested manually language validation as it needs a valid api key to be tested.

Sorry, I thought that this issue was for D8, should I open a new issue for D8 or change this issue to D8?

Changed to D8

Apply the last api changes and added tests using the mock.

+++ b/src/MicrosoftTranslatorUi.php
@@ -30,11 +34,42 @@ class MicrosoftTranslatorUi extends TranslatorPluginUiBase {
+    $translator = $form_state->getFormObject()->getEntity();
+    $supported_remote_languages = $entity = $translator->getPlugin()->getSupportedRemoteLanguages($translator);
+    if (!empty($supported_remote_languages)) {
+      foreach ($form_state->getValue('remote_languages_mappings') as $local_language => $remote_language) {
+        // Empty targets are unsupported languages.
+        if ($remote_language == '') {
+          continue;
+        }
 
-    return parent::pluginSettingsForm($form, $form_state, $translator);

This comment isn't really correct, they're not unsupported, they're just not mapped.

Also ,this logic doesn't seem to belong here, it's not specific to Microsoft translator, we could do this for all translators that support remote mappings?

The second part is tricky then, of course, if we remove the first part.

So we might move the logic to the parent then? Should I do it here #2256959: Validate language mapping selection?

I discussed this with @Berdir, we are going to move the mapping validation to the TranslatorForm in the issue #2256959: Validate language mapping selection
So here is the patch with just the validaton of the client id and client secret and the changes in the API.

+++ b/src/MicrosoftTranslatorUi.php
@@ -30,11 +34,30 @@ class MicrosoftTranslatorUi extends TranslatorPluginUiBase {
+    $supported_remote_languages = $entity = $translator->getPlugin()->getSupportedRemoteLanguages($translator);

This is not right.

Done.

Small fix.

The last was wrong, this is the good way.

Ok, committed.

Yay! We start to have real setting validations! :-)