If you're using nix or nixos you can just do a nix-shell or if using lorri or direnv: direnv allow
If you're using docker for postgres I supplied a docker-compose.yml
docker-compose up -dMIX_ENV=test mix do ecto.drop, ecto.create, ecto.migratemix test
It looks like Repo.select(from x in Schema, select: %{something: ^result}) when result = 123 will cause an error as follows:
1) test I expect this to not crash! (BugExampleTest)
test/bug_example_test.exs:6
** (DBConnection.EncodeError) Postgrex expected a binary, got 123. Please make sure the value you are passing matches the definition in your table or in your query or convert the value accordingly.
code: assert {0, ^expectation} = BugExample.Repo.one(from x in BugExample.Schema, select: {count(x), ^expectation})
stacktrace:
(postgrex 0.16.5) lib/postgrex/type_module.ex:947: Postgrex.DefaultTypes.encode_params/3
(postgrex 0.16.5) lib/postgrex/query.ex:75: DBConnection.Query.Postgrex.Query.encode/3
(db_connection 2.4.3) lib/db_connection.ex:1304: DBConnection.encode/5
(db_connection 2.4.3) lib/db_connection.ex:1404: DBConnection.run_prepare_execute/5
(db_connection 2.4.3) lib/db_connection.ex:1508: DBConnection.run/6
(db_connection 2.4.3) lib/db_connection.ex:644: DBConnection.parsed_prepare_execute/5
(db_connection 2.4.3) lib/db_connection.ex:697: DBConnection.execute/4
(ecto_sql 3.9.2) lib/ecto/adapters/postgres/connection.ex:102: Ecto.Adapters.Postgres.Connection.execute/4
(ecto_sql 3.9.2) lib/ecto/adapters/sql.ex:858: Ecto.Adapters.SQL.execute!/5
(ecto_sql 3.9.2) lib/ecto/adapters/sql.ex:828: Ecto.Adapters.SQL.execute/6
(ecto 3.9.4) lib/ecto/repo/queryable.ex:229: Ecto.Repo.Queryable.execute/4
(ecto 3.9.4) lib/ecto/repo/queryable.ex:19: Ecto.Repo.Queryable.all/3
(ecto 3.9.4) lib/ecto/repo/queryable.ex:151: Ecto.Repo.Queryable.one/3
test/bug_example_test.exs:17: (test)Whereas doing Repo.select(from x in Schema, select: %{something: 123}) works as one would expect.