Show a generic diff command hint in hex.outdated output

Per review feedback on #1137: listing a `mix hex.package diff` command
for every outdated package adds significant output. Show a single
generic command hint (`mix hex.package diff APP FROM..TO`) instead.

https://claude.ai/code/session_0162egDzWnK8wcGhWZxSk2mB

Author: claude

lib/mix/tasks/hex.outdated.ex

@@ -189,7 +189,6 @@ defmodule Mix.Tasks.Hex.Outdated do
     values = versions |> Enum.map(&format_all_row/1) |> maybe_sort_by(opts[:sort])
 
     diff_links = Enum.map(versions, &build_diff_link/1) |> Enum.reject(&is_nil/1)
-    diff_commands = Enum.map(versions, &build_diff_command/1) |> Enum.reject(&is_nil/1)
 
     if Enum.empty?(values) do
       Hex.Shell.info("No hex dependencies")
@@ -199,8 +198,8 @@ defmodule Mix.Tasks.Hex.Outdated do
 
       base_message = "Run `mix hex.outdated APP` to see requirements for a specific dependency."
       diff_message = maybe_diff_message(diff_links)
-      diff_commands_message = maybe_diff_commands_message(diff_commands)
-      Hex.Shell.info(["\n", base_message, diff_message, diff_commands_message])
+      diff_command_message = maybe_diff_command_message(diff_links)
+      Hex.Shell.info(["\n", base_message, diff_message, diff_command_message])
 
       outdated = outdated(versions)
       any_updatable? = any_possible_to_update?(outdated)
@@ -332,17 +331,10 @@ defmodule Mix.Tasks.Hex.Outdated do
       diff_link(diff_links)
   end
 
-  defp build_diff_command([package, _dep_only, lock, latest, _requirements]) do
-    if Version.compare(lock, latest) == :lt do
-      "mix hex.package diff #{package} #{lock}..#{latest}"
-    end
-  end
-
-  defp maybe_diff_commands_message([]), do: ""
+  defp maybe_diff_command_message([]), do: ""
 
-  defp maybe_diff_commands_message(diff_commands) do
-    commands = Enum.map_join(diff_commands, "\n", &("  " <> &1))
-    "\n\nTo view the diff of a specific update, run:\n" <> commands
+  defp maybe_diff_command_message(_diff_links) do
+    "\n\nTo view the diff of a specific update, run `mix hex.package diff APP FROM..TO`."
   end
 
   defp diff_link(diff_links) do

test/mix/tasks/hex.outdated_test.exs

@@ -668,7 +668,7 @@ defmodule Mix.Tasks.Hex.OutdatedTest do
     end)
   end
 
-  test "outdated shows diff commands for outdated packages" do
+  test "outdated shows a generic diff command hint when updates are available" do
     Mix.Project.push(OutdatedDeps.MixProject)
 
     in_tmp(fn ->
@@ -683,10 +683,8 @@ defmodule Mix.Tasks.Hex.OutdatedTest do
       lines = flush()
       output = Enum.map_join(lines, "\n", fn {_, _, [line]} -> line end)
 
-      assert output =~ "To view the diff of a specific update, run:"
-      assert output =~ "mix hex.package diff ex_doc 0.0.1..0.1.0"
-      assert output =~ "mix hex.package diff foo 0.1.0..0.1.1"
-      refute output =~ "mix hex.package diff bar"
+      assert output =~
+               "To view the diff of a specific update, run `mix hex.package diff APP FROM..TO`."
     end)
   end