feat(helpers): add support for complex intermediate return types in fake method

[ghost]

Fixes #1850

• Add support for complex intermediate return types in fake method #1850

I started to add support for complex intermediate return types in the fake method of the helpers module as described in #1850.

Currently, it is a work in progress. I would like to get feedback from you.

I wrote a few tests and will add more in the next days, for example for locale data references.

[codecov]

Codecov Report

Merging #2381 (acccce2) into next (c158b38) will decrease coverage by 0.01%.
Report is 31 commits behind head on next.
The diff coverage is 100.00%.

❗ Current head acccce2 differs from pull request most recent head bc9e533. Consider uploading reports for the commit bc9e533 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #2381      +/-   ##
==========================================
- Coverage   99.60%   99.60%   -0.01%     
==========================================
  Files        2660     2786     +126     
  Lines      246345   252572    +6227     
  Branches     1086     1089       +3     
==========================================
+ Hits       245375   251577    +6202     
- Misses        943      968      +25     
  Partials       27       27              

Files Changed	Coverage Δ
src/locales/en/finance/credit_card/index.ts	100.00% <ø> (ø)
src/locale/eo.ts	100.00% <100.00%> (ø)
src/locale/index.ts	100.00% <100.00%> (ø)
src/locale/yo_NG.ts	100.00% <100.00%> (ø)
src/locales/da/commerce/department.ts	100.00% <100.00%> (ø)
src/locales/da/commerce/index.ts	100.00% <100.00%> (ø)
src/locales/da/commerce/product_description.ts	100.00% <100.00%> (ø)
src/locales/da/commerce/product_name.ts	100.00% <100.00%> (ø)
src/locales/da/company/adjective.ts	100.00% <100.00%> (ø)
src/locales/da/company/buzz_adjective.ts	100.00% <100.00%> (ø)
... and 137 more

... and 4 files with indirect coverage changes

[xDivisionByZerox]

Currently if a property is unknown on we receive an error:

Invalid module method or definition: person.abc
- faker.person.abc is not a function
- faker.definitions.person.abc is not an array

I would prefer if we could throw this error here as well and add a case for faker.person is a function but does not return an object with the property abc. I'll gladly take suggestions on the phrasing.

[xDivisionByZerox]

I'm not sure if this test actually adds any value since we already have a test for an array argument:

faker/test/modules/helpers.spec.ts

Lines 1082 to 1089 in 604d52d

	it('should be able to pass multiple dynamic templates', () => {
	expect(faker.definitions.location.city_name).toContain(
	faker.helpers.fake([
	'{{location.city_name}}',
	'{{location.cityName}}',
	])
	);
	});

[ST-DDT]

Please also add a test that checks that if the fn didnt return a complex object and the property was requested that then an error is thrown.

Also I'm not sure about the current implementation.
E.g. Because it would break for {{airline.airport().iataCode}}
and it no longer supports it for 4 or deeper properties, but I'm not sure it has to.

[matthewmayer]

Which of these do we expect to work

A {{airline.airport().iataCode}}

B {{airline.airport.iataCode}}

C {{airline.airport.iataCode()}}

[ST-DDT]

Which of these do we expect to work

A {{airline.airport().iataCode}}

B {{airline.airport.iataCode}}

C {{airline.airport.iataCode()}}

I would expect A and B to work.

[ST-DDT]

Thanks for your contribution ❤️, we used it to create a new PR for this feature.

---

Superseded by #2550

• feat(helpers): add support for complex intermediate types #2550