uiRecordApi is missing implementation of utility functions

[hagai-shatz]

It is impossible to test code that uses getFieldValue from uiRecordApi without reimplementing the function.
The mock for uiRecordApi in lwc-recipes includes the implementation of getFieldValue:
https://github.com/trailheadapps/lwc-recipes/blob/master/force-app/test/jest-mocks/lightning/uiRecordApi.js

It would make sense to have the same implementation provided here.

[trevor-bliss]

Hi @hagai-shatz. Thanks for the Issue. In general, I don't think it's a good idea to add the actual implementation for these methods because they can differ from the real code or get out of date over time. The lwc-recipe implementation is a good example of this. The real getFieldValue doesn't account for a results prop on the first param, and returns undefined instead of null if no value is found.

I guess for this one we can make an exception though since I think the functionality is unlikely to change much and it is a pain to have to copy that implementation whenever you use it. I'm going to modify what is in the lwc-recipe repo though so more closely represent what the real function does.

[hagai-shatz]

Hi @trevor-bliss
I totally agree that services should be mocked, but it is almost impossible to test your code if utility functions like getFieldValue and getFieldDisplayValue are not implemented.
We took the code from lwc-recipe into our project to run tests and as you mentioned, it didn't work as expected, not just the data.result support, but also no support for string path.

This is the implementation we have now:

	if (data) {
		const fields = fieldReference.fieldApiName ?
			[fieldReference.objectApiName].concat(fieldReference.fieldApiName.split('.')) :
			fieldReference.split('.');
		let record = data.result || data;
		if (record.apiName === fields.shift()) {
			while (record && record.fields && fields.length) {
				record = record.fields[fields.shift()];
			}
			return record && record.value;
		}
		return null;
	}

Following your comment, I will probably remove the support for data.result and return undefined; at the end.

Notice that we implemented similar mocking for @salesfroce/apex/getSObjectValue