Adds test to Ecto fields of type {:map, :float}

Signed-off-by: Tallys Martins <tallysmartins@gmail.com>

test/elixir_bench/repo_test.exs

@@ -0,0 +1,83 @@
+defmodule ElixirBench.RepoTest do
+  alias ElixirBench.Repo
+  alias ElixirBench.Benchmarks
+  use ElixirBench.DataCase
+
+  defmodule RepoMeasurement do
+    use Ecto.Schema
+    import Ecto.Changeset
+
+    schema "repo_measurements" do
+      field :map_float_percentiles, {:map, :float}
+      field :map_percentiles, :map
+    end
+
+    @fields [:map_float_percentiles, :map_percentiles]
+    def changeset(%RepoMeasurement{} = measurement, attrs) do
+      measurement
+      |> cast(attrs, @fields)
+    end
+  end
+
+  defmodule CreateMeasurementMigration do
+    use Ecto.Migration
+
+    def change do
+      create table(:repo_measurements) do
+        add(:map_float_percentiles, {:map, :float})
+        add(:map_percentiles, :map)
+      end
+    end
+  end
+
+  # A bug in ecto with {:map, :float} fields
+  # See discussions in https://github.com/elixir-ecto/ecto/issues/2637
+  # This test will let us know when the bug is fixed in future updates of ecto,
+  # after that we can remove this
+
+  test "raise when exponential notation is given to field of type {:map, :float}" do
+    :ok = Ecto.Migrator.up(Repo, 0, CreateMeasurementMigration, log: false)
+    {value, _} = Float.parse("416500")
+    assert ^value = 4.165e5
+
+    percentiles = %{"50" => value, "99" => value}
+
+    changeset =
+      RepoMeasurement.changeset(%RepoMeasurement{}, %{"map_float_percentiles" => percentiles})
+
+    assert {:ok, _} = Repo.insert(changeset)
+
+    assert_raise ArgumentError,
+                 ~r/cannot load `%{"50" => 416500, "99" => 416500}` as type {:map, :float} for field `map_float_percentiles`/,
+                 fn ->
+                   Repo.all(RepoMeasurement)
+                 end
+
+    :ok = Ecto.Migrator.down(Repo, 0, CreateMeasurementMigration, log: false)
+  end
+
+  test "not raise when float notation is given for field of type {:map, :float}" do
+    :ok = Ecto.Migrator.up(Repo, 0, CreateMeasurementMigration, log: false)
+    percentiles = %{"50" => 4101.0, "99" => 4160.0}
+
+    changeset =
+      RepoMeasurement.changeset(%RepoMeasurement{}, %{"map_float_percentiles" => percentiles})
+
+    assert {:ok, measurement} = Repo.insert(changeset)
+    ^measurement = Repo.one(RepoMeasurement)
+
+    assert %{"50" => 4101.0, "99" => 4160.0} = measurement.map_float_percentiles
+    :ok = Ecto.Migrator.down(Repo, 0, CreateMeasurementMigration, log: false)
+  end
+
+  test "not raise when exponential notation is given to field of type :map" do
+    :ok = Ecto.Migrator.up(Repo, 0, CreateMeasurementMigration, log: false)
+    percentiles = %{"50" => 4.165e5, "99" => 4.165e5}
+    changeset = RepoMeasurement.changeset(%RepoMeasurement{}, %{"map_percentiles" => percentiles})
+    assert {:ok, _} = Repo.insert(changeset)
+
+    measurement = Repo.one(RepoMeasurement)
+    assert %{"50" => 416_500, "99" => 416_500} = measurement.map_percentiles
+    :ok = Ecto.Migrator.down(Repo, 0, CreateMeasurementMigration, log: false)
+  end
+end