Check for file conflicts before copying. Closes phoenixframework#2193 (…

…phoenixframework#2195)

lib/mix/phoenix.ex

@@ -206,6 +206,28 @@ defmodule Mix.Phoenix do
     Path.join(web_prefix(), rel_path)
   end
 
+  @doc """
+  Prompts to continue if any files exist.
+  """
+  def prompt_for_conflicts(generator_files) do
+    file_paths = Enum.map(generator_files, fn {_, _, path} -> path end)
+
+    case Enum.filter(file_paths, &File.exists?(&1)) do
+      [] -> :ok
+      conflicts ->
+        Mix.shell.info"""
+        The following files conflict with new files to be generated:
+
+        #{conflicts |> Enum.map(&"  * #{&1}") |> Enum.join("\n")}
+
+        See the --web option to namespace similarly named resources
+        """
+        unless Mix.shell.yes?("Proceeed with interactive overwrite?") do
+          System.halt()
+        end
+    end
+  end
+
   defp web_module(base) do
     if base |> to_string() |> String.ends_with?(".Web") do
       Module.concat(base, nil)

lib/mix/tasks/phx.gen.context.ex

@@ -71,11 +71,19 @@ defmodule Mix.Tasks.Phx.Gen.Context do
     binding = [context: context, schema: schema]
     paths = Mix.Phoenix.generator_paths()
 
+    prompt_for_conflicts(context)
+
     context
     |> copy_new_files(paths, binding)
     |> print_shell_instructions()
   end
 
+  defp prompt_for_conflicts(context) do
+    context
+    |> files_to_be_generated()
+    |> Mix.Phoenix.prompt_for_conflicts()
+  end
+
   def build(args) do
     switches = [binary_id: :boolean, table: :string, web: :string]
     {opts, parsed, _} = OptionParser.parse(args, switches: switches)
@@ -91,6 +99,10 @@ defmodule Mix.Tasks.Phx.Gen.Context do
     {context, schema}
   end
 
+  def files_to_be_generated(%Context{schema: schema}) do
+    Gen.Schema.files_to_be_generated(schema)
+  end
+
   def copy_new_files(%Context{schema: schema} = context, paths, binding) do
     Gen.Schema.copy_new_files(schema, paths, binding)
     inject_schema_access(context, paths, binding)
@@ -100,7 +112,9 @@ defmodule Mix.Tasks.Phx.Gen.Context do
   end
 
   defp inject_schema_access(%Context{file: file} = context, paths, binding) do
-    unless Context.pre_existing?(context) do
+    if Context.pre_existing?(context) do
+      Mix.shell.info([:green, "* injecting ", :reset, Path.relative_to_cwd(file)])
+    else
       Mix.Generator.create_file(file, Mix.Phoenix.eval_from(paths, "priv/templates/phx.gen.context/context.ex", binding))
     end
 
@@ -114,7 +128,9 @@ defmodule Mix.Tasks.Phx.Gen.Context do
   end
 
   defp inject_tests(%Context{test_file: test_file} = context, paths, binding) do
-    unless Context.pre_existing_tests?(context) do
+    if Context.pre_existing_tests?(context) do
+      Mix.shell.info([:green, "* injecting ", :reset, Path.relative_to_cwd(test_file)])
+    else
       Mix.Generator.create_file(test_file, Mix.Phoenix.eval_from(paths, "priv/templates/phx.gen.context/context_test.exs", binding))
     end
 

lib/mix/tasks/phx.gen.html.ex

@@ -84,17 +84,25 @@ defmodule Mix.Tasks.Phx.Gen.Html do
     binding = [context: context, schema: schema, inputs: inputs(schema)]
     paths = Mix.Phoenix.generator_paths()
 
+    prompt_for_conflicts(context)
+
     context
     |> copy_new_files(paths, binding)
     |> print_shell_instructions()
   end
 
-  def copy_new_files(%Context{schema: schema} = context, paths, binding) do
+  defp prompt_for_conflicts(context) do
+    context
+    |> files_to_be_generated()
+    |> Kernel.++(Gen.Context.files_to_be_generated(context))
+    |> Mix.Phoenix.prompt_for_conflicts()
+  end
+
+  def files_to_be_generated(%Context{schema: schema}) do
     web_prefix = Mix.Phoenix.web_prefix()
     test_prefix = Mix.Phoenix.test_prefix()
     web_path = to_string(schema.web_path)
-
-    Mix.Phoenix.copy_from paths, "priv/templates/phx.gen.html", "", binding, [
+    [
       {:eex, "controller.ex",       Path.join([web_prefix, "controllers", web_path, "#{schema.singular}_controller.ex"])},
       {:eex, "edit.html.eex",       Path.join([web_prefix, "templates", web_path, schema.singular, "edit.html.eex"])},
       {:eex, "form.html.eex",       Path.join([web_prefix, "templates", web_path, schema.singular, "form.html.eex"])},
@@ -104,7 +112,12 @@ defmodule Mix.Tasks.Phx.Gen.Html do
       {:eex, "view.ex",             Path.join([web_prefix, "views", web_path, "#{schema.singular}_view.ex"])},
       {:eex, "controller_test.exs", Path.join([test_prefix,"controllers", web_path, "#{schema.singular}_controller_test.exs"])},
     ]
+  end
+
 
+  def copy_new_files(%Context{} = context, paths, binding) do
+    files = files_to_be_generated(context)
+    Mix.Phoenix.copy_from(paths, "priv/templates/phx.gen.html", "", binding, files)
     Gen.Context.copy_new_files(context, paths, binding)
     context
   end

lib/mix/tasks/phx.gen.json.ex

@@ -73,25 +73,39 @@ defmodule Mix.Tasks.Phx.Gen.Json do
     binding = [context: context, schema: schema]
     paths = Mix.Phoenix.generator_paths()
 
+    prompt_for_conflicts(context)
+
     context
     |> copy_new_files(paths, binding)
     |> print_shell_instructions()
   end
 
-  def copy_new_files(%Context{schema: schema} = context, paths, binding) do
+  defp prompt_for_conflicts(context) do
+    context
+    |> files_to_be_generated()
+    |> Kernel.++(Gen.Context.files_to_be_generated(context))
+    |> Mix.Phoenix.prompt_for_conflicts()
+  end
+
+  def files_to_be_generated(%Context{schema: schema}) do
     web_prefix = Mix.Phoenix.web_prefix()
     test_prefix = Mix.Phoenix.test_prefix()
     web_path = to_string(schema.web_path)
 
-    Mix.Phoenix.copy_from paths, "priv/templates/phx.gen.json", "", binding, [
+    [
       {:eex,     "controller.ex",          Path.join([web_prefix, "controllers", web_path, "#{schema.singular}_controller.ex"])},
       {:eex,     "view.ex",                Path.join([web_prefix, "views", web_path, "#{schema.singular}_view.ex"])},
       {:eex,     "controller_test.exs",    Path.join([test_prefix, "controllers", web_path, "#{schema.singular}_controller_test.exs"])},
       {:new_eex, "changeset_view.ex",      Path.join([web_prefix, "views/changeset_view.ex"])},
       {:new_eex, "fallback_controller.ex", Path.join([web_prefix, "controllers/fallback_controller.ex"])},
     ]
+  end
 
+  def copy_new_files(%Context{} = context, paths, binding) do
+    files = files_to_be_generated(context)
+    Mix.Phoenix.copy_from paths, "priv/templates/phx.gen.json", "", binding, files
     Gen.Context.copy_new_files(context, paths, binding)
+
     context
   end
 

lib/mix/tasks/phx.gen.schema.ex

@@ -91,11 +91,19 @@ defmodule Mix.Tasks.Phx.Gen.Schema do
     schema = build(args, [])
     paths = Mix.Phoenix.generator_paths()
 
+    prompt_for_conflicts(schema)
+
     schema
     |> copy_new_files(paths, schema: schema)
     |> print_shell_instructions()
   end
 
+  defp prompt_for_conflicts(schema) do
+    schema
+    |> files_to_be_generated()
+    |> Mix.Phoenix.prompt_for_conflicts()
+  end
+
   def build(args, parent_opts, help \\ __MODULE__) do
     {schema_opts, parsed, _} = OptionParser.parse(args, switches: @switches)
     [schema_name, plural | attrs] = validate_args!(parsed, help)
@@ -107,6 +115,10 @@ defmodule Mix.Tasks.Phx.Gen.Schema do
     schema
   end
 
+  def files_to_be_generated(%Schema{} = schema) do
+    [{:eex, "schema.ex", schema.file}]
+  end
+
   def copy_new_files(%Schema{} = schema, paths, binding) do
     migration =
       schema.module
@@ -117,9 +129,8 @@ defmodule Mix.Tasks.Phx.Gen.Schema do
       |> Phoenix.Naming.underscore()
       |> String.replace("/", "_")
 
-    Mix.Phoenix.copy_from paths, "priv/templates/phx.gen.schema", "", binding, [
-      {:eex, "schema.ex", schema.file}
-    ]
+    files = files_to_be_generated(schema)
+    Mix.Phoenix.copy_from(paths,"priv/templates/phx.gen.schema", "", binding, files)
 
     if schema.migration? do
       Mix.Phoenix.copy_from paths, "priv/templates/phx.gen.schema", "", binding, [