test: add Mongo Asset's FindByID unit testing

[KeisukeYamashita]

Overview

I have added initial unit testing for the MongoDB based on this issue for "small start" 👉 reearth/reearth#273.
See details (requirements) in that issue.

I implemented one for a trial to avoid conflicts and decide how we are going to test this methods.

What I've done

I have added unit test for the Asset repository's FindByID method.

What I haven't done

Add unit tests for all methods for Assets or other repositories.
This is because I wanted to "start small" since we need to discuss the policy and the implementation design first so that we don't waste time.

How I tested

The testings are done by the CI GitHub Actions workflow.
This can be also tested locally.

# Skip testing
go test -timeout 30s -run '^TestFindByID$' github.com/reearth/reearth-backend/internal/infrastructure/mongo

# Test (after launching MongoDB instance in your local environment)
REEARTH_DB=mongodb://localhost go test -timeout 30s -run '^TestFindByID$' github.com/reearth/reearth-backend/internal/infrastructure/mongo

Which point I want you to review particularly

• How the testing(s) should be done
  • Table testing
  • Variable namings
  • etc

Memo

Please feel free to give me any feedback as this is the starting point of adding unit tests to the repository layer.

[codecov]

Codecov Report

Merging #139 (bc0019a) into main (4f72b87) will decrease coverage by 2.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #139      +/-   ##
==========================================
- Coverage   36.68%   34.61%   -2.07%     
==========================================
  Files         331      349      +18     
  Lines       29890    31755    +1865     
==========================================
+ Hits        10964    10992      +28     
- Misses      17925    19760    +1835     
- Partials     1001     1003       +2     

Impacted Files	Coverage Δ
internal/infrastructure/mongo/config.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/dataset_schema.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/property_schema.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/plugin.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/tag.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/dataset.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/asset.go	25.26% <0.00%> (ø)
internal/infrastructure/mongo/auth_request.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/scene_lock.go	0.00% <0.00%> (ø)
internal/infrastructure/mongo/team.go	0.00% <0.00%> (ø)
... and 8 more

[KeisukeYamashita]

TODO ✔️

• Need to add the REEARTH_DB env for testing in the CI

[rot1024]

Thank you! How about creating a helper function like this one?

func connect(t *testing.T) func() (*mongodoc.Client, func()) {
	t.Helper()

	// Skip unit testing if "REEARTH_DB" is not configured
	// See details: https://github.com/reearth/reearth/issues/273
	db := os.Getenv("REEARTH_DB")
	if db == "" {
		t.SkipNow()
		return nil
	}

	c, _ := mongo.Connect(
		context.Background(),
		options.Client().
			ApplyURI(db).
			SetConnectTimeout(time.Second*10),
	)

	return func() {
		database, _ := uuid.New()
		databaseName := "reearth-test-" + string(database[:])
		client := mongodoc.NewClient(databaseName, c)
		return client, func() {
			_ = c.Database(databaseName).Drop(context.Background())
		}
	}
}

Usage:

func TestFindByID(t *testing.T) {
	// ...
	initDB := connect(t)
 
	for _, tc := range tests {
		tc := tc
		t.Run(tc.Name, func() {
			t.Paralell()
			client, dropDB := initDB()
			defer dropDB()

			repo := NewAsset(client)	  
			ctx := context.Background()
			err := repo.Save(ctx, want)
			assert.NoError(t, err)
	  
			got, err := repo.FindByID(ctx, want.ID())
			// ...
		})
	}
}

[KeisukeYamashita]

Thank you for your review 😄