Check if directory is free to be used

src/alr/alr-commands-init.adb

@@ -411,6 +411,18 @@ package body Alr.Commands.Init is
 
       Query_Crate_Name (Args, Info);
 
+      --  check if project name is already in use in dir
+      if Cmd.In_Place then
+         if Dirs.Exists ("alire.toml") then
+            Reportaise_Wrong_Arguments ("alire.toml already exists");
+         end if;
+      else
+         if Dirs.Exists (Dirs."/" (To_String (Info.Name), "alire.toml")) then
+            Reportaise_Wrong_Arguments
+              (To_String (Info.Name) & "/alire.toml already exists");
+         end if;
+      end if;
+
       if Cmd.Bin then
          Info.Is_Library := False;
       elsif Cmd.Lib then

testsuite/tests/init/crate-name-validation/test.py

@@ -40,4 +40,12 @@ def assert_that(name, fails_with):
 for crate_type in CRATE_TYPES:
     run_alr('init', f"--{crate_type}", f"{VALID_NAME}{crate_type}")
 
+# Test if Project already exists
+run_alr('init', 'foo')
+p = run_alr('init', 'foo', complain_on_error=False)
+assert_match("ERROR: foo/alire.toml already exists", p.out)
+
+p = run_alr('--chdir=foo', 'init', '--in-place', 'foo', complain_on_error=False)
+assert_match("ERROR: alire.toml already exists", p.out)
+
 print('SUCCESS')