Add initial filtering capability and tests to listings service

[avaleske]

Issue

CityOfDetroit/affordable-housing-app#63

Addresses # (issue)

• This change addresses the issue in full
• This change addresses only certain aspects of the issue
• This change is a dependency for another issue
• This change has a dependency from another issue

Description

Adds an initial filtering capability to the listings service, and some basic tests

Details

• Adds the ability to filter by neighborhood, using an exact string match. Other filter types will need to work differently
• Adds test scaffolding to the Listings controller
• Adds basic tests to the Listings service

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Prototype/POC (not to merge)
• This change is a refactor/address technical debt
• This change requires a documentation update
• This change requires a SQL Script

How Can This Be Tested/Reviewed?

Please describe the tests that you ran to verify your changes. Provide instructions so we can review. Please also list any relevant details for your test configuration

• Run yarn test -t "listings" to run the new tests
• Navigate to localhost:3100/listings?neighborhood=Fox%20Creek and observe that the listings are filtered. Try replacing with other neighborhood names (run select neighborhood, count(*) from property group by neighborhood; in the db to see them all)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have reviewed the changes in a desktop view
• I have reviewed the changes in a mobile view
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have assigned reviewers
• I have updated the changelog to include a description of my changes

[anders-schneider]

LGTM

And thanks for adding the test scaffolding!

[anders-schneider]

One other question here: should the tests live in /backend/core/src or /backend/core/test? So far it looks like there are only e2e tests in /backend/core/test, but my instinct would be to add these unit tests to that test directory. There may be a good reason to include them in /backend/core/src, though?

[avaleske]

@anders-schneider the other unit tests are in the same directory as the code under test, for example: https://github.com/CityOfDetroit/bloom/blob/main/backend/core/src/user/user.controller.spec.ts

[anders-schneider]

Ah sorry I missed that, sounds good on including unit tests in the same directory like you have it!

[willrlin]

Why the switch here and elsewhere to use this.repository instead of Listing?

[avaleske]

Listing is using the entity object directly, but this.repository is the injected entity. That lets me swap it with a mock in the tests.