Magento 2 : fix php 7.2 error : Countable interface not implemented

[gmachure]

Preconditions (*)

1. Magento ver. 2.3.0-beta32
2. PHP Version : 7.2.12

Steps to reproduce (*)

1. Create custom module.
2. Add fileUploader form element in ui_component form).

<field name="image">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="dataType" xsi:type="string">string</item>
                    <item name="source" xsi:type="string">store</item>
                    <item name="label" xsi:type="string" translate="true">Image</item>
                    <item name="visible" xsi:type="boolean">true</item>
                    <item name="formElement" xsi:type="string">fileUploader</item>
                    <item name="allowedExtensions" xsi:type="string">jpg jpeg gif png</item>
                    <item name="uploaderConfig" xsi:type="array">
                        <item name="url" xsi:type="url" path="zodio_store/store/uploader"/>
                    </item>
                    <item name="notice" xsi:type="string" translate="true">Allowed extensions : jpg jpeg gif png. recommended size 600px*264px</item>
                    <item name="validation" xsi:type="array">
                        <item name="required-entry" xsi:type="boolean">true</item>
                    </item>
                </item>
            </argument>
        </field>

Expected result (*)

1. 

Actual result (*)

Error Message : Warning: count(): Parameter must be an array or an object that implements Countable in <base_dir>/vendor/magento/framework/File/Uploader.php on line 550

[magento-engcom-team]

Hi @gmachure. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

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• Information on your environment
• Steps to reproduce
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Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

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@gmachure do you confirm that you was able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

[magento-engcom-team]

Hi @engcom-backlog-nazar. Thank you for working on this issue.
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[magento-engcom-team]

@engcom-backlog-nazar Thank you for verifying the issue. Based on the provided information internal tickets MAGETWO-96476 were created

Hi @gmachure i'm able to reproduce this issue on 2.3-develop instance