Add unit test for repository collaboration (#825)

- Add a few extra test cases and test functions for the collaboration
model to get everything covered by tests (except for error handling, as
we cannot suddenly mock errors from the database).

```
-> % go tool cover -func=coverage.out | grep "code.gitea.io/gitea/models/repo/collaboration.go"
```

Before:
```
code.gitea.io/gitea/models/repo/collaboration.go:28:                            init                                            100.0%
code.gitea.io/gitea/models/repo/collaboration.go:39:                            GetCollaborators                                61.5%
code.gitea.io/gitea/models/repo/collaboration.go:65:                            CountCollaborators                              0.0%
code.gitea.io/gitea/models/repo/collaboration.go:70:                            GetCollaboration                                0.0%
code.gitea.io/gitea/models/repo/collaboration.go:83:                            IsCollaborator                                  100.0%
code.gitea.io/gitea/models/repo/collaboration.go:87:                            getCollaborations                               42.9%
code.gitea.io/gitea/models/repo/collaboration.go:102:                           ChangeCollaborationAccessMode                   77.8%
code.gitea.io/gitea/models/repo/collaboration.go:141:                           IsOwnerMemberCollaborator                       0.0%
```

After:
```
code.gitea.io/gitea/models/repo/collaboration.go:28:                            init                                            100.0%
code.gitea.io/gitea/models/repo/collaboration.go:39:                            GetCollaborators                                61.5%
code.gitea.io/gitea/models/repo/collaboration.go:65:                            CountCollaborators                              100.0%
code.gitea.io/gitea/models/repo/collaboration.go:70:                            GetCollaboration                                100.0%
code.gitea.io/gitea/models/repo/collaboration.go:83:                            IsCollaborator                                  100.0%
code.gitea.io/gitea/models/repo/collaboration.go:87:                            getCollaborations                               100.0%
code.gitea.io/gitea/models/repo/collaboration.go:102:                           ChangeCollaborationAccessMode                   83.3%
code.gitea.io/gitea/models/repo/collaboration.go:141:                           IsOwnerMemberCollaborator                       87.5%
```

Co-authored-by: Gusted <postmaster@gusted.xyz>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/825

models/repo/collaboration_test.go

@@ -33,6 +33,19 @@ func TestRepository_GetCollaborators(t *testing.T) {
 	test(2)
 	test(3)
 	test(4)
+
+	// Test db.ListOptions
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 22})
+
+	collaborators1, err := repo_model.GetCollaborators(db.DefaultContext, repo.ID, db.ListOptions{PageSize: 1, Page: 1})
+	assert.NoError(t, err)
+	assert.Len(t, collaborators1, 1)
+
+	collaborators2, err := repo_model.GetCollaborators(db.DefaultContext, repo.ID, db.ListOptions{PageSize: 1, Page: 2})
+	assert.NoError(t, err)
+	assert.Len(t, collaborators2, 1)
+
+	assert.NotEqualValues(t, collaborators1[0].ID, collaborators2[0].ID)
 }
 
 func TestRepository_IsCollaborator(t *testing.T) {
@@ -66,5 +79,80 @@ func TestRepository_ChangeCollaborationAccessMode(t *testing.T) {
 
 	assert.NoError(t, repo_model.ChangeCollaborationAccessMode(db.DefaultContext, repo, unittest.NonexistentID, perm.AccessModeAdmin))
 
+	// Disvard invalid input.
+	assert.NoError(t, repo_model.ChangeCollaborationAccessMode(db.DefaultContext, repo, 4, perm.AccessMode(unittest.NonexistentID)))
+
 	unittest.CheckConsistencyFor(t, &repo_model.Repository{ID: repo.ID})
 }
+
+func TestRepository_CountCollaborators(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	repo1 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 4})
+	count, err := repo_model.CountCollaborators(repo1.ID)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 2, count)
+
+	repo2 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 22})
+	count, err = repo_model.CountCollaborators(repo2.ID)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 2, count)
+
+	// Non-existent repository.
+	count, err = repo_model.CountCollaborators(unittest.NonexistentID)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 0, count)
+}
+
+func TestRepository_IsOwnerMemberCollaborator(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	repo1 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 3})
+
+	// Organisation owner.
+	actual, err := repo_model.IsOwnerMemberCollaborator(repo1, 2)
+	assert.NoError(t, err)
+	assert.True(t, actual)
+
+	// Team member.
+	actual, err = repo_model.IsOwnerMemberCollaborator(repo1, 4)
+	assert.NoError(t, err)
+	assert.True(t, actual)
+
+	// Normal user.
+	actual, err = repo_model.IsOwnerMemberCollaborator(repo1, 1)
+	assert.NoError(t, err)
+	assert.False(t, actual)
+
+	repo2 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 4})
+
+	// Collaborator.
+	actual, err = repo_model.IsOwnerMemberCollaborator(repo2, 4)
+	assert.NoError(t, err)
+	assert.True(t, actual)
+
+	repo3 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 15})
+
+	// Repository owner.
+	actual, err = repo_model.IsOwnerMemberCollaborator(repo3, 2)
+	assert.NoError(t, err)
+	assert.True(t, actual)
+}
+
+func TestRepo_GetCollaboration(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 4})
+
+	// Existing collaboration.
+	collab, err := repo_model.GetCollaboration(db.DefaultContext, repo.ID, 4)
+	assert.NoError(t, err)
+	assert.NotNil(t, collab)
+	assert.EqualValues(t, 4, collab.UserID)
+	assert.EqualValues(t, 4, collab.RepoID)
+
+	// Non-existing collaboration.
+	collab, err = repo_model.GetCollaboration(db.DefaultContext, repo.ID, 1)
+	assert.NoError(t, err)
+	assert.Nil(t, collab)
+}