Use elixir internal distance function instead of a library for command similarity comparison.

Elixir provides String.jaro_distance function, which is similar to
the levenstain distance.
This allows us to remove a dependency.

deps/rabbitmq_cli/lib/rabbitmq/cli/core/parser.ex

@@ -16,9 +16,8 @@
 defmodule RabbitMQ.CLI.Core.Parser do
   alias RabbitMQ.CLI.Core.{CommandModules, Config}
 
-  # This assumes the average word letter count in
+  # Use the same jaro distance limit as in Elixir `did_you_mean`
-  # the English language is 5.
+  @jaro_distance_limit 0.77
-  @levenshtein_distance_limit 5
 
   def default_switches() do
     [
@@ -167,19 +166,18 @@ defmodule RabbitMQ.CLI.Core.Parser do
     nil
   end
 
-  defp command_suggestion(cmd_name, module_map) do
+  defp command_suggestion(typed, module_map) do
     suggestion =
       module_map
       |> Map.keys()
-      |> Enum.map(fn cmd ->
+      |> Enum.map(fn existing ->
-        {cmd, Simetric.Levenshtein.compare(cmd, cmd_name)}
+        {existing, String.jaro_distance(existing, typed)}
       end)
-      |> Enum.min_by(fn {_, distance} -> distance end)
+      |> Enum.max_by(fn {_, distance} -> distance end)
 
     case suggestion do
-      {cmd, distance} when distance <= @levenshtein_distance_limit ->
+      {cmd, distance} when distance >= @jaro_distance_limit ->
         {:suggest, cmd}
-
       _ ->
         nil
     end

deps/rabbitmq_cli/mix.exs

@@ -88,7 +88,6 @@ defmodule RabbitMQCtl.MixfileBase do
     elixir_deps = [
       {:json, "~> 1.0.0"},
       {:csv, "~> 2.0.0"},
-      {:simetric, "~> 0.2.0"},
 
       {:amqp, "~> 0.2.2", only: :test},
       {:dialyxir, "~> 0.5", only: :test, runtime: false},