[#47] Add compare/2 shim to support Decimal 1.5

Fixes #47. Kudos to @brianberlin for the original fix:

#48

I just tinkered around the edges and added support for running the test
suite against both versions of Decimal.

.travis.yml

@@ -1,10 +1,14 @@
 language: elixir
 elixir:
-  - 1.7.4
+  - 1.10
 otp_release:
   - 21.0
+env:
+  matrix:
+    - DECIMAL_VERSION=1.5
+    - DECIMAL_VERSION=2.0
 script:
   - bin/test
 after_script:
-- MIX_ENV=dev mix deps.get
-- MIX_ENV=dev mix inch.report
+  - MIX_ENV=dev mix deps.get
+  - MIX_ENV=dev mix inch.report

lib/number/currency.ex

@@ -109,7 +109,7 @@ defmodule Number.Currency do
   defp get_format(number, options) do
     number = if is_float(number), do: Decimal.from_float(number), else: Decimal.new(number)
 
-    case Decimal.compare(number, Decimal.new(0)) do
+    case Number.Decimal.compare(number, Decimal.new(0)) do
       :lt -> {Decimal.abs(number), options[:negative_format] || "-#{options[:format]}"}
       _ -> {number, options[:format]}
     end

lib/number/decimal.ex

@@ -0,0 +1,24 @@
+defmodule Number.Decimal do
+  @moduledoc false
+
+  # Temporary shim that allow Number to work with <2.0 versions of Decimal.
+  #
+  # In Decimal 1.5, Decimal.compare/2 would return -1, 1, or 0 decimals.
+  # In Decimal >=2.0, Decimal.compare/2 returns :lt, :gt, :eq.
+  #
+  # See https://github.com/danielberkompas/number/issues/47
+  def compare(a, b) do
+    result = Decimal.compare(a, b)
+
+    cond do
+      result in [:lt, Decimal.new(-1)] ->
+        :lt
+
+      result in [:gt, Decimal.new(1)] ->
+        :gt
+
+      result in [:eq, Decimal.new(0)] ->
+        :eq
+    end
+  end
+end

lib/number/human.ex

@@ -4,7 +4,7 @@ defmodule Number.Human do
   """
 
   import Number.Delimit, only: [number_to_delimited: 2]
-  import Decimal, only: [compare: 2]
+  import Number.Decimal, only: [compare: 2]
 
   @doc """
   Formats and labels a number with the appropriate English word.
@@ -65,7 +65,8 @@ defmodule Number.Human do
       compare(number, ~d(1_000_000)) in [:gt, :eq] and compare(number, ~d(1_000_000_000)) == :lt ->
         delimit(number, ~d(1_000_000), "Million", options)
 
-      compare(number, ~d(1_000_000_000)) in [:gt, :eq] and compare(number, ~d(1_000_000_000_000)) == :lt ->
+      compare(number, ~d(1_000_000_000)) in [:gt, :eq] and
+          compare(number, ~d(1_000_000_000_000)) == :lt ->
         delimit(number, ~d(1_000_000_000), "Billion", options)
 
       compare(number, ~d(1_000_000_000_000)) in [:gt, :eq] and

mix-decimal1.lock

@@ -0,0 +1,26 @@
+%{
+  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm", "7af5c7e09fe1d40f76c8e4f9dd2be7cebd83909f31fee7cd0e9eadc567da8353"},
+  "certifi": {:hex, :certifi, "2.5.2", "b7cfeae9d2ed395695dd8201c57a2d019c0c43ecaf8b8bcb9320b40d6662f340", [:rebar3], [{:parse_trans, "~>3.3", [hex: :parse_trans, repo: "hexpm", optional: false]}], "hexpm", "3b3b5f36493004ac3455966991eaf6e768ce9884693d9968055aeeeb1e575040"},
+  "decimal": {:hex, :decimal, "1.5.0", "b0433a36d0e2430e3d50291b1c65f53c37d56f83665b43d79963684865beab68", [:mix], [], "hexpm", "130926580655f34d759dd25f5d723fd233c9bbe0399cde57e2a1adea9ed92e08"},
+  "decimal_arithmetic": {:hex, :decimal_arithmetic, "0.1.2", "26c9ddf5f06a5f9c6524dcc165f5829b80faa2bb0184747409086f21d7fd735b", [:mix], [{:decimal, "~> 1.5", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm"},
+  "dialyxir": {:hex, :dialyxir, "0.5.1", "b331b091720fd93e878137add264bac4f644e1ddae07a70bf7062c7862c4b952", [:mix], [], "hexpm"},
+  "earmark": {:hex, :earmark, "1.4.3", "364ca2e9710f6bff494117dbbd53880d84bebb692dafc3a78eb50aa3183f2bfd", [:mix], [], "hexpm", "8cf8a291ebf1c7b9539e3cddb19e9cef066c2441b1640f13c34c1d3cfc825fec"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.10", "6603d7a603b9c18d3d20db69921527f82ef09990885ed7525003c7fe7dc86c56", [:mix], [], "hexpm", "8e2d5370b732385db2c9b22215c3f59c84ac7dda7ed7e544d7c459496ae519c0"},
+  "ex_doc": {:hex, :ex_doc, "0.22.6", "0fb1e09a3e8b69af0ae94c8b4e4df36995d8c88d5ec7dbd35617929144b62c00", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm", "1e0aceda15faf71f1b0983165e6e7313be628a460e22a031e32913b98edbd638"},
+  "excoveralls": {:hex, :excoveralls, "0.13.1", "b9f1697f7c9e0cfe15d1a1d737fb169c398803ffcbc57e672aa007e9fd42864c", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "b4bb550e045def1b4d531a37fb766cbbe1307f7628bf8f0414168b3f52021cce"},
+  "exjsx": {:hex, :exjsx, "4.0.0", "60548841e0212df401e38e63c0078ec57b33e7ea49b032c796ccad8cde794b5c", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, repo: "hexpm", optional: false]}], "hexpm", "32e95820a97cffea67830e91514a2ad53b888850442d6d395f53a1ac60c82e07"},
+  "hackney": {:hex, :hackney, "1.16.0", "5096ac8e823e3a441477b2d187e30dd3fff1a82991a806b2003845ce72ce2d84", [:rebar3], [{:certifi, "2.5.2", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "6.0.1", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.0", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.6", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm", "3bf0bebbd5d3092a3543b783bf065165fa5d3ad4b899b836810e513064134e18"},
+  "idna": {:hex, :idna, "6.0.1", "1d038fb2e7668ce41fbf681d2c45902e52b3cb9e9c77b55334353b222c2ee50c", [:rebar3], [{:unicode_util_compat, "0.5.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "a02c8a1c4fd601215bb0b0324c8a6986749f807ce35f25449ec9e69758708122"},
+  "inch_ex": {:hex, :inch_ex, "2.0.0", "24268a9284a1751f2ceda569cd978e1fa394c977c45c331bb52a405de544f4de", [:mix], [{:bunt, "~> 0.2", [hex: :bunt, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "96d0ec5ecac8cf63142d02f16b7ab7152cf0f0f1a185a80161b758383c9399a8"},
+  "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
+  "jsx": {:hex, :jsx, "2.8.3", "a05252d381885240744d955fbe3cf810504eb2567164824e19303ea59eef62cf", [:mix, :rebar3], [], "hexpm", "fc3499fed7a726995aa659143a248534adc754ebd16ccd437cd93b649a95091f"},
+  "makeup": {:hex, :makeup, "1.0.3", "e339e2f766d12e7260e6672dd4047405963c5ec99661abdc432e6ec67d29ef95", [:mix], [{:nimble_parsec, "~> 0.5", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "2e9b4996d11832947731f7608fed7ad2f9443011b3b479ae288011265cdd3dad"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.14.1", "4f0e96847c63c17841d42c08107405a005a2680eb9c7ccadfd757bd31dabccfb", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "f2438b1a80eaec9ede832b5c41cd4f373b38fd7aa33e3b22d9db79e640cbde11"},
+  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm", "69b09adddc4f74a40716ae54d140f93beb0fb8978d8636eaded0c31b6f099f16"},
+  "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
+  "nimble_parsec": {:hex, :nimble_parsec, "0.6.0", "32111b3bf39137144abd7ba1cce0914533b2d16ef35e8abc5ec8be6122944263", [:mix], [], "hexpm", "27eac315a94909d4dc68bc07a4a83e06c8379237c5ea528a9acff4ca1c873c52"},
+  "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm", "17ef63abde837ad30680ea7f857dd9e7ced9476cdd7b0394432af4bfc241b960"},
+  "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm", "fec8660eb7733ee4117b85f55799fd3833eb769a6df71ccf8903e8dc5447cfce"},
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
+  "unicode_util_compat": {:hex, :unicode_util_compat, "0.5.0", "8516502659002cec19e244ebd90d312183064be95025a319a6c7e89f4bccd65b", [:rebar3], [], "hexpm", "d48d002e15f5cc105a696cf2f1bbb3fc72b4b770a184d8420c8db20da2674b38"},
+}

mix.exs

@@ -10,6 +10,7 @@ defmodule Number.Mixfile do
       build_embedded: Mix.env() == :prod,
       start_permanent: Mix.env() == :prod,
       test_coverage: [tool: ExCoveralls],
+      lockfile: lockfile(),
       preferred_cli_env: [
         coveralls: :test,
         "coveralls.detail": :test,
@@ -52,4 +53,11 @@ defmodule Number.Mixfile do
       }
     ]
   end
+
+  defp lockfile() do
+    case System.get_env("DECIMAL_VERSION") do
+      "1" -> "mix-decimal1.lock"
+      _ -> "mix.lock"
+    end
+  end
 end