BUG - @sap-ux/ui5-middleware-fe-mockserver not managing dates as entity key

[archetypon]

Description

@sap-ux/ui5-middleware-fe-mockserver is not actually managing datetime as entity key.
I have an entity like as follow:

<EntityType Name="MyEntity">
        <Key>
          <PropertyRef Name="stringKey1"/>
          <PropertyRef Name="stringKey2"/>
          <PropertyRef Name="dateTimeKey"/>
        </Key>
        <Property Name="stringKey1" Type="Edm.String" Nullable="false"/>
        <Property Name="stringKey2" Type="Edm.String" MaxLength="10" Nullable="false"/>
        <Property Name="dateTimeKey" Type="Edm.DateTime" Nullable="false" sap:display-format="Date"/>
</EntityType>

When trying to retrieve a single entity with proper key as for example
/MyEntity(stringKey1='something',stringKey2='somethingagain',dateTimeKey=datetime'2024-01-01T00%3A00%3A00')
the mock server returns a 404 http code response.
The server expect to treat the attribute as a string (so for instance '/Date(1234567890)/').

Steps to Reproduce

Steps to reproduce the behavior:

1. Run a UI5 application with mock server
2. Request an entity with Edm.DateTime type as key attribute

Expected results

It should let use it as key

Actual results

Is returning a 404

Version/Components/Environment

Add any other context about the problem here
OS:

• Mac OS
• Windows
• Other

Root Cause Analysis

Problem

{describe the problem}

Fix

{describe the fix}

Why was it missed

{Some explanation why this issue might have been missed during normal development/testing cycle}

How can we avoid this

{if we don’t want to see this type of issues anymore what we should do to prevent}

[helencorrigan]

FYI @nlunets

[AdrianDengusiak]

We have found similar issue, but with filtering.

OData Service V2
Property:
<Property Name="DeliveryDate" Type="Edm.DateTime" Nullable="false" sap:label="Delivery Date" sap:creatable="false" sap:updatable="false" sap:display-format="Date"/>

When using Smart Table with Smart Filter Bar, we get empty response. Fails with both own mock data, but also generated one.

[nlunets]

Could you provide the request and expected response from both case ?
I have a potential fix but i want to be sure not to miss some case :)