Added unit converters, resolves #7

lib/exw3.ex

@@ -1,5 +1,59 @@
 defmodule ExW3 do
 
+  Module.register_attribute __MODULE__, :unit_map, persist: true, accumulate: false
+  
+  @unit_map %{
+    :noether => 0,
+    :wei => 1,
+    :kwei => 1_000,
+    :Kwei => 1_000,
+    :babbage => 1_000,
+    :femtoether => 1_000,
+    :mwei => 1_000_000,
+    :Mwei => 1_000_000,
+    :lovelace => 1_000_000,
+    :picoether => 1_000_000,
+    :gwei => 1_000_000_000,
+    :Gwei => 1_000_000_000,
+    :shannon => 1_000_000_000,
+    :nanoether => 1_000_000_000,
+    :nano => 1_000_000_000,
+    :szabo => 1_000_000_000_000,
+    :microether => 1_000_000_000_000,
+    :micro => 1_000_000_000_000,
+    :finney => 1_000_000_000_000_000,
+    :milliether => 1_000_000_000_000_000,
+    :milli => 1_000_000_000_000_000,
+    :ether => 1_000_000_000_000_000_000,
+    :kether => 1_000_000_000_000_000_000_000,
+    :grand => 1_000_000_000_000_000_000_000,
+    :mether => 1_000_000_000_000_000_000_000_000,
+    :gether => 1_000_000_000_000_000_000_000_000_000,
+    :tether => 1_000_000_000_000_000_000_000_000_000_000
+  }
+
+  @spec get_unit_map() :: %{}
+  @doc "Returns the map used for ether unit conversion"
+  def get_unit_map do
+    @unit_map
+  end
+
+  def to_wei(num, key) do
+    if @unit_map[key] do
+      num * @unit_map[key]
+    else
+      throw "#{key} not valid unit"
+    end
+  end
+
+  def from_wei(num, key) do
+    if @unit_map[key] do
+      num / @unit_map[key]
+    else
+      throw "#{key} not valid unit"
+    end
+  end
+
   @spec keccak256(binary()) :: binary()
   @doc "Returns a 0x prepended 32 byte hash of the input string"
   def keccak256(string) do

test/exw3_test.exs

@@ -181,7 +181,7 @@ defmodule EXW3Test do
   
     receive do
       {:event, {_filter_id, data}} ->
-	Agent.update(agent, fn list -> [data | list] end)	
+	Agent.update(agent, fn list -> [data | list] end)
     after 3_000 ->
 	raise "Never received event"
     end
@@ -341,4 +341,57 @@ defmodule EXW3Test do
 
   end
 
+  test "unit conversion to_wei" do
+    
+    assert ExW3.to_wei(1, :wei) == 1
+    assert ExW3.to_wei(1, :kwei) == 1_000
+    assert ExW3.to_wei(1, :Kwei) == 1_000
+    assert ExW3.to_wei(1, :babbage) == 1_000
+    assert ExW3.to_wei(1, :mwei) == 1_000_000
+    assert ExW3.to_wei(1, :Mwei) == 1_000_000
+    assert ExW3.to_wei(1, :lovelace) == 1_000_000
+    assert ExW3.to_wei(1, :gwei) == 1_000_000_000
+    assert ExW3.to_wei(1, :Gwei) == 1_000_000_000
+    assert ExW3.to_wei(1, :shannon) == 1_000_000_000
+    assert ExW3.to_wei(1, :szabo) == 1_000_000_000_000
+    assert ExW3.to_wei(1, :finney) == 1_000_000_000_000_000
+    assert ExW3.to_wei(1, :ether) == 1_000_000_000_000_000_000
+    assert ExW3.to_wei(1, :kether) == 1_000_000_000_000_000_000_000
+    assert ExW3.to_wei(1, :grand) == 1_000_000_000_000_000_000_000
+    assert ExW3.to_wei(1, :mether) == 1_000_000_000_000_000_000_000_000
+    assert ExW3.to_wei(1, :gether) == 1_000_000_000_000_000_000_000_000_000
+    assert ExW3.to_wei(1, :tether) == 1_000_000_000_000_000_000_000_000_000_000
+
+    assert ExW3.to_wei(1, :kwei) == ExW3.to_wei(1, :femtoether)
+    assert ExW3.to_wei(1, :szabo) == ExW3.to_wei(1, :microether)
+    assert ExW3.to_wei(1, :finney) == ExW3.to_wei(1, :milliether)
+    assert ExW3.to_wei(1, :milli) == ExW3.to_wei(1, :milliether)
+    assert ExW3.to_wei(1, :milli) == ExW3.to_wei(1000, :micro)
+
+    {:ok, agent} = Agent.start_link(fn -> false end)
+
+    try do
+      ExW3.to_wei(1, :wei1)
+    catch
+      _ -> Agent.update(agent, fn _ -> true  end)
+    end
+
+    assert Agent.get(agent, fn state -> state end)
+  end
+
+  test "unit conversion from wei" do
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :wei) == 1_000_000_000_000_000_000
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :kwei) == 1_000_000_000_000_000
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :mwei) == 1_000_000_000_000
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :gwei) == 1_000_000_000
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :szabo) == 1_000_000
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :finney) == 1_000
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :ether) == 1
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :kether) == 0.001
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :grand) == 0.001
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :mether) == 0.000001
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :gether) == 0.000000001
+    assert ExW3.from_wei(1_000_000_000_000_000_000, :tether) == 0.000000000001
+  end
+
 end