ExUnit assertions for comparing data structures by identity.


The package can be installed by adding assert_identity to your list of dependencies in mix.exs:

def deps do
    {:assert_identity, "~> 0.1.0"}


Check the documentation for more details.

AssertIdentity is designed to be used with ExUnit. It provides assertions to check that two inputs have the same identity. This is useful, for example, when dealing with Ecto structs which may not be strictly equivalent due to e.g. association preloading.

For convenience, you can import the helpers in your test case:

def MyApp.DataCase do
  use ExUnit.CaseTemplate

  using do
    quote do
      import MyApp.DataCase
      import AssertIdentity

Or otherwise just directly in your test:

def MyApp.ModuleTest do
  import AssertIdentity

Use the assert_ids_match function to check that two maps, structs, or lists of the former have the same identity (i.e., the same values for the :id key). You can optionally specify the key name if not :id.

def MyApp.PostTest do
  use MyApp.DataCase

  test "list_posts/0 returns all posts" do
    post = insert(:post)
    assert_ids_match(Posts.list_posts(), [post])


Contributions are welcome! To make changes, clone the repo, make sure tests pass, and then open a PR on GitHub.

git clone
cd assert_identity
mix deps.get
mix test


AssertIdentity is Copyright © 2020 NewAperio. It is free software, and may be redistributed under the terms specified in the LICENSE file.

About NewAperio

AssertIdentity is built by NewAperio, LLC.

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