C#•12mo ago

✅ Mocking DB operations

Say I have a function and I need to verify that the saved UserFollow object will:

Cause the user objects to be retrieved if UserFollow retrieves them eagerly
Cause the userFollow to be retrieved if a User is retrieved with said fields eagerly

public async Task<bool> AddFollowerByPrivateIdAsync(int userPrivateId, int followerPrivateId) {

public async Task<bool> AddFollowerByPrivateIdAsync(int userPrivateId, int followerPrivateId) {

public async Task<bool> AddFollowerByPrivateIdAsync(int userPrivateId, int followerPrivateId) {

public async Task<bool> AddFollowerByPrivateIdAsync(int userPrivateId, int followerPrivateId) {

var user = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == userPrivateId);

var user = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == userPrivateId);

var user = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == userPrivateId);

var user = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == userPrivateId);

var follower = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == followerPrivateId);

var follower = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == followerPrivateId);

var follower = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == followerPrivateId);

var follower = await _context.Users.FirstOrDefaultAsync(u => u.PrivateId == followerPrivateId);

if (user == null || follower == null) {

if (user == null || follower == null) {

if (user == null || follower == null) {

if (user == null || follower == null) {

return false;

return false;

var userFollow = new UserFollow {

var userFollow = new UserFollow {

var userFollow = new UserFollow {

var userFollow = new UserFollow {

FollowedId =

FollowedId =

FollowedId =

FollowedId = [

user.Id

user.Id

user.Id

user.Id]

FollowerId =

FollowerId =

FollowerId =

FollowerId = [

follower.Id

follower.Id

follower.Id

follower.Id]

Type = FollowType.Requested,

Type = FollowType.Requested,

Type = FollowType.Requested,

Type = FollowType.Requested,

Followed = user,

Followed = user,

Followed = user,

Followed = user,

Follower = follower

Follower = follower

Follower = follower

Follower = follower

};

};

};

};

_context.UserFollows.Add(userFollow);

_context.UserFollows.Add(userFollow);

_context.UserFollows.Add(userFollow);

_context.UserFollows.Add(userFollow);

await _context.SaveChangesAsync();

await _context.SaveChangesAsync();

await _context.SaveChangesAsync();

await _context.SaveChangesAsync();

return true;

return true;

How would I test this? I have looked at XUnit and MockItEasy but it doesn't look like they are dealing with the Database, but rather dependencies for abstracted code.

Thalnos•1/20/25, 6:51 AM

You should really create an abstraction for anything and everything if you want to mock it easily for testing. That’s one of the reasons why wrapping EFC into your own repository pattern even tho it already is an implementation of it is beneficial

TThalnos You should really create an abstraction for anything and everything if you want ...

surwrenOP•1/20/25, 6:59 AM

I don't really understand

I mock it (in all the examples I've seen) I'm just feeding it the behavior to output? How do I test the actual DB behavior itself

TeBeCo•1/20/25, 7:12 AM

$efmock

TTeBeCo $efmock

MODiX•1/20/25, 7:12 AM

see $mockef

TeBeCo•1/20/25, 7:12 AM

$mockef

TTeBeCo $mockef

MODiX•1/20/25, 7:12 AM

https://github.com/romantitov/MockQueryable

GitHub

GitHub - romantitov/MockQueryable: Mocking Entity Framework Core op...

Mocking Entity Framework Core operations such ToListAsync, FirstOrDefaultAsync etc - romantitov/MockQueryable

TeBeCo•1/20/25, 7:13 AM

BUT

TeBeCo•1/20/25, 7:13 AM

you don't want to do that

TeBeCo•1/20/25, 7:13 AM

you want to use testcontainertestcontainer

TeBeCo•1/20/25, 7:13 AM

and spin an empty Database

TeBeCo•1/20/25, 7:13 AM

and make an integration test

TeBeCo•1/20/25, 7:13 AM

that's way mnore reliable

TeBeCo•1/20/25, 7:51 AM

what database are you using ?

TTeBeCo you don't want to do that

surwrenOP•1/20/25, 7:52 AM

wait, why would mockef not be reliable if it is recommended by modix too

TeBeCo•1/20/25, 7:52 AM

and where do you want the test to be ran

TTeBeCo what database are you using ?

surwrenOP•1/20/25, 7:52 AM

MSSQL

Ssurwren wait, why would mockef not be reliable if it is recommended by modix too 😳

TeBeCo•1/20/25, 7:52 AM

because both exists and you make the shots

TeBeCo•1/20/25, 7:52 AM

modix don't recommend anything

TeBeCo•1/20/25, 7:52 AM

TeBeCo•1/20/25, 7:52 AM

it's just a tag I typed

TeBeCo•1/20/25, 7:53 AM

modix have that stored as bookmark

TTeBeCo and where do you want the test to be ran

surwrenOP•1/20/25, 7:53 AM

I actually don't know that there are options for where tests can be ran, I came from Java where I would create a folder called 'tests' and it would just not let the build pass if tests failed (when I pressed the play button)

TeBeCo•1/20/25, 7:53 AM

I sent it because that's close to your quesiton if you still want to try

TeBeCo•1/20/25, 7:53 AM

but I also raised the point that integration test can generally be better

TeBeCo•1/20/25, 7:53 AM

especially for web app

surwrenOP•1/20/25, 7:53 AM

sure, I do believe integration tests are close to what I am looking for anyway

TeBeCo•1/20/25, 7:54 AM

where do you want these test to be ran is important

TeBeCo•1/20/25, 7:54 AM

only locally ? only you ? all the team ?
only the ci/cd ?
both local + ci/cd ?

TeBeCo•1/20/25, 7:54 AM

and when

surwrenOP•1/20/25, 7:55 AM

if we start at most basic it's just locally/only me for now

but I'm curious how it could be done with local + ci/cd with all the team too, since I would want to learn how to do that at some point

TeBeCo•1/20/25, 7:55 AM

if it's team + cicd

TeBeCo•1/20/25, 7:55 AM

you'll need to make sure docker can run on all these "local dev computer"

TeBeCo•1/20/25, 7:56 AM

so all your teamate

TeBeCo•1/20/25, 7:56 AM

and that your CI/CD can also run container

TeBeCo•1/20/25, 7:56 AM

like Azure devops have that backed in

TeBeCo•1/20/25, 7:56 AM

github too

TeBeCo•1/20/25, 7:56 AM

now if you're dealing with "your own VM" for build agent

TeBeCo•1/20/25, 7:56 AM

that's less fun

TeBeCo•1/20/25, 7:56 AM

you'll need to ensure these computer can run container

TeBeCo•1/20/25, 7:56 AM

and for company ... docker desktop might induce a fee

TeBeCo•1/20/25, 7:57 AM

docker itself (without the "desktop part") does not though

TeBeCo•1/20/25, 7:57 AM

or you use podmanpodman with testcontainertestcontainer

TeBeCo•1/20/25, 7:57 AM

but you need a "container runtime" installed and running

TeBeCo•1/20/25, 7:57 AM

which means on windows WSL2 on dev computer

TeBeCo•1/20/25, 7:57 AM

so easy a VERY RECENT win10 version or a win11

TeBeCo•1/20/25, 7:58 AM

and probably at least 16GB ram / ssd

TeBeCo•1/20/25, 7:58 AM

now the other issue you have is MSSQL

TeBeCo•1/20/25, 7:58 AM

you'd have to look PROBABLY for the linux version of MSSQL docker image

TeBeCo•1/20/25, 7:58 AM

because running Windows Containers is not light at all

TeBeCo•1/20/25, 7:59 AM

https://learn.microsoft.com/en-us/sql/linux/quickstart-install-connect-docker?view=sql-server-ver16&tabs=cli&pivots=cs1-powershell

Docker: Install Containers for SQL Server on Linux - SQL Server

This quickstart shows how to use Docker to run the SQL Server Linux container images. You connect to a database and run a query.

✅ Mocking DB operations

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