initial testing for list-usb-drives

overlays.nix

@@ -43,4 +43,40 @@ final: prev: {
       }
     );
   };
+
+  list-usb-drives = prev.writeShellApplication {
+    name = "list-usb-drives";
+    runtimeInputs = with prev; [
+      findutils
+      gawk
+      coreutils
+      gnugrep
+      util-linux
+    ];
+
+    excludeShellChecks = [
+      "SC2086"
+      "SC2157"
+      "SC2155"
+    ];
+
+    text = ''
+      # Allow overriding the disk-by-id directory for testing
+      DISK_BY_ID_DIR="''${LIST_USB_DRIVES_DISK_DIR:-/dev/disk/by-id}"
+
+      # Mock lsblk for testing
+      if [ -n "''${LIST_USB_DRIVES_TEST_MODE:-}" ]; then
+        lsblk() {
+          echo "''$LIST_USB_DRIVES_MOCK_DATA" | tr '|' '\n' | while IFS=: read -r pattern response; do
+            case "$(basename "$3")" in *"$pattern"*) echo "$response"; return ;; esac
+          done || echo "UNKNOWN_MODEL UNKNOWN_SERIAL"
+        }
+      fi
+
+      # Scan for USB devices in the specified directory
+      if [ -d "$DISK_BY_ID_DIR" ]; then
+        find "$DISK_BY_ID_DIR" -name "usb*" | grep -v "part[0-9]\$" | while read -r drive; do lsblk -no model,serial "$drive" | head -n1 | tr -d '\n' | tr " " "_" && echo -e " $(echo \"$drive\" | cut -d':' -f2-)"; done | column -t --table-columns=DRIVE,BAY | sort -n -k 2
+      fi
+    '';
+  };
 }

tests/list-usb-drives.nix

@@ -0,0 +1,46 @@
+{
+  config,
+  lib,
+  pkgs,
+  inputs,
+  ...
+}:
+let
+  # Create pkgs with list-usb-drives overlay
+  testPkgs = import inputs.nixpkgs {
+    system = pkgs.system;
+    overlays = [ (import ../overlays.nix) ];
+  };
+in
+testPkgs.testers.runNixOSTest {
+  name = "list-usb-drives test";
+
+  nodes.machine =
+    { pkgs, ... }:
+    {
+      environment.systemPackages = [
+        testPkgs.list-usb-drives
+      ];
+    };
+
+  testScript = ''
+    start_all()
+    machine.wait_for_unit("multi-user.target")
+
+    # Create mock USB device symlinks
+    machine.succeed("mkdir -p /tmp/mock-by-id")
+    machine.succeed("touch /tmp/mock-by-id/usb-drive1-0:0")
+    machine.succeed("touch /tmp/mock-by-id/usb-drive2-0:1") 
+    machine.succeed("touch /tmp/mock-by-id/usb-drive1-0:0-part1")  # Should be filtered out
+
+    # Test with mock data
+    mock_data = "drive1:Model1 Serial1|drive2:Model2 Serial2"
+    output = machine.succeed(f"LIST_USB_DRIVES_DISK_DIR=/tmp/mock-by-id LIST_USB_DRIVES_TEST_MODE=1 LIST_USB_DRIVES_MOCK_DATA='{mock_data}' list-usb-drives")
+
+    # Expected exact output
+    expected = 'DRIVE           BAY\nModel1_Serial1  0"\nModel2_Serial2  1"\n'
+
+    assert output == expected
+    print("✓ Mock USB device test passed")
+  '';
+}

tests/tests.nix

@@ -11,4 +11,5 @@ in
   zfsTest = handleTest ./zfs.nix;
   testTest = handleTest ./testTest.nix;
   minecraftTest = handleTest ./minecraft.nix;
+  listUsbDrivesTest = handleTest ./list-usb-drives.nix;
 }