Enum: several key-value pairs not identical

Problem

According to the documentation topic Defining Control Properties, there are specific restrictions when defining a new enum type:

• The value for each key must be a string literal, equal to the key itself.
• [...] only keys and values of type string are supported.

...

Apart from the above documented restrictions; when assigning enum values declaratively in XML, JSON (e.g. manifest.json), or HTML (data-*), the actual enum values visible in the source code must be passed instead of the keys. This leads to issues like #1703 where the documented key name "Put" was attempted but the actual expected value is "PUT".

While the real values can be accessed and assigned via sap.ui.define / require in JS, it is difficult to do so declaratively in XML or JSON. Developers would have to inspect the source framework code to discover the actual enum values since only the keys are visible in the API reference. Additionally, non-ManagedObject properties, such as the roundingMode in formatOptions, are not validated either unlike in https://github.com/SAP/openui5/issues/2166.

Findings

Here are public enum types that I've looped through and that do not align with the above documented restrictions:[^1]

Similar issues / fixes in the past

• https://github.com/SAP/openui5/issues/2169 (https://github.com/SAP/openui5/commit/7b6f6a19c75d185a27dae871e4eb8bb95ee2da70) (https://stackoverflow.com/a/43946624/5846045)
• https://github.com/SAP/openui5/issues/1759#issuecomment-412899129 (https://github.com/SAP/openui5/commit/c7e39e4f5793b4ce6a44bf38354bd3980761ed95)
• https://github.com/SAP/openui5/issues/1703
• https://github.com/SAP/openui5/commit/90b30ac7a720e6c1c0be2936ce39465cacd6464a
• https://github.com/SAP/openui5/commit/367b728d389f2789d3a2c84b088a16ad552944cb

Ideas to reduce future issues?

• UI5 linter detecting faulty enum definitions
• Future fatal logging by DataType.registerEnum if the passed object contains faulty enum definitions
• Allowing enums to be required and assigned in XML such as to ManagedObject properties and binding infos (Cf. https://x.com/wridgeu/status/1567955929051570178 by @wridgeu)
• Downporting fixes
• Adding a test to ensure future introduction of new enums comply with the documented restrictions

[^1]: Excluded from the search were the libs sap.apf, sap.ca.scfld.md, sap.fiori, sap.ui.demoapps, sap.ui.documentation, sap.ui.server.java, sap.ui.server.abap, sap.ui.support, sap.ushell_abap, themelib*, *.test*, *.tools*, and libs / enum types that are either deprecated or restricted. Types related to MockServer, jQuery, and test were also skipped. IllustratedMessageType is ignored too since the IllustratedMessage property illustrationType explicitly states that the illustration set name (e.g. sapIllus-) must be prepended.