Function TestCreateUserDoesNotSaveAllUsers

weed/iamapi/iamapi_test.go:624–659

TestCreateUserDoesNotSaveAllUsers is a regression test for the bug where creating a new user triggered a full SaveConfiguration over all existing identities (causing N file writes + reload cycles in the filer_etc store). The fix uses credentialManager.CreateUser for a targeted single-file write.

(t *testing.T)

// identities (causing N file writes + reload cycles in the filer_etc store).
// The fix uses credentialManager.CreateUser for a targeted single-file write.
func TestCreateUserDoesNotSaveAllUsers(t *testing.T) {
	srv, cm, counter := iamApiServerWithCredentialManager()
	ctx := context.Background()

	// Pre-populate three existing users.
	for _, name := range []string{"existing-1", "existing-2", "existing-3"} {
		require.NoError(t, cm.CreateUser(ctx, &iam_pb.Identity{Name: name}))
	}

	// Create a new user via the HTTP API.
	params := &iam.CreateUserInput{UserName: aws.String("new-user")}
	req, _ := iam.New(session.New()).CreateUserRequest(params)
	_ = req.Build()
	out := CreateUserResponse{}
	resp, err := executeRequestWith(srv, req.HTTPRequest, &out)
	require.NoError(t, err)
	require.Equal(t, http.StatusOK, resp.Code)

	// The new user must appear in the store.
	newUser, userErr := cm.GetUser(ctx, "new-user")
	require.NoError(t, userErr)
	require.Equal(t, "new-user", newUser.Name)

	// Critical: full SaveConfiguration (PutS3ApiConfiguration) must NOT have
	// been called. Before the fix it was called once per CreateUser, rewriting
	// every existing user file and triggering a cascade of reload events.
	assert.Equal(t, 0, counter.putCalled,
		"CreateUser must not trigger a full PutS3ApiConfiguration over all users")

	// All pre-existing users must still be intact.
	for _, name := range []string{"existing-1", "existing-2", "existing-3"} {
		u, err := cm.GetUser(ctx, name)
		require.NoError(t, err, "pre-existing user %s should still exist", name)
		assert.Equal(t, name, u.Name)
	}
}