Require recent decimal versions

lib/ecto/changeset.ex

@@ -3152,7 +3152,7 @@ defmodule Ecto.Changeset do
          _spec_function,
          %Decimal{} = target_value
        ) do
-    result = Decimal.compare(value, target_value) |> normalize_compare()
+    result = Decimal.compare(value, target_value)
 
     case decimal_compare(result, spec_key) do
       true -> nil
@@ -3175,17 +3175,6 @@ defmodule Ecto.Changeset do
     end
   end
 
-  # TODO: Remove me once we support Decimal 2.0 only
-  # Support mismatch between API for Decimal.compare/2 for versions 1.6 and 2.0
-  defp normalize_compare(result) do
-    case result do
-      %Decimal{coef: 1, sign: -1} -> :lt
-      %Decimal{coef: 0} -> :eq
-      %Decimal{coef: 1, sign: 1} -> :gt
-      _ -> result
-    end
-  end
-
   defp decimal_new(term) when is_float(term), do: Decimal.from_float(term)
   defp decimal_new(term), do: Decimal.new(term)
 

lib/ecto/query/builder.ex

@@ -1128,13 +1128,7 @@ defmodule Ecto.Query.Builder do
   @doc """
   Negates the given number.
   """
-  # TODO: Remove check when we depend on decimal v2.0
-  if Code.ensure_loaded?(Decimal) and function_exported?(Decimal, :negate, 1) do
-    def negate!(%Decimal{} = decimal), do: Decimal.negate(decimal)
-  else
-    def negate!(%Decimal{} = decimal), do: Decimal.minus(decimal)
-  end
-
+  def negate!(%Decimal{} = decimal), do: Decimal.negate(decimal)
   def negate!(number) when is_number(number), do: -number
 
   @doc """

lib/ecto/type.ex

@@ -858,8 +858,6 @@ defmodule Ecto.Type do
 
   defp cast_decimal(term) when is_binary(term) do
     case Decimal.parse(term) do
-      {:ok, decimal} -> check_decimal(decimal, false)
-      # The following two clauses exist to support earlier versions of Decimal.
       {decimal, ""} -> check_decimal(decimal, false)
       {_, remainder} when is_binary(remainder) and byte_size(remainder) > 0 -> :error
       :error -> :error

mix.exs

@@ -33,7 +33,7 @@ defmodule Ecto.MixProject do
   defp deps do
     [
       {:telemetry, "~> 0.4 or ~> 1.0"},
-      {:decimal, "~> 1.6 or ~> 2.0"},
+      {:decimal, "~> 2.0"},
       {:jason, "~> 1.0", optional: true},
       {:ex_doc, "~> 0.20", only: :docs}
     ]