add long-device-name test & example

example/long-device-name.nix

@@ -0,0 +1,34 @@
+{
+  disko.devices = {
+    disk = {
+      vdb = {
+        device = "/dev/disk/by-id/some-disk-id";
+        name = "this-is-some-super-long-name-to-test-what-happens-when-the-name-is-too-long";
+        type = "disk";
+        content = {
+          type = "gpt";
+          partitions = {
+            ESP = {
+              type = "EF00";
+              size = "500M";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = "/boot";
+              };
+            };
+            root = {
+              size = "100%";
+              content = {
+                type = "filesystem";
+                format = "ext4";
+                mountpoint = "/";
+              };
+            };
+          };
+        };
+      };
+    };
+  };
+}
+

tests/long-device-name.nix

@@ -0,0 +1,11 @@
+{ pkgs ? import <nixpkgs> { }
+, diskoLib ? pkgs.callPackage ../lib { }
+}:
+diskoLib.testLib.makeDiskoTest {
+  inherit pkgs;
+  name = "long-device-name";
+  disko-config = ../example/long-device-name.nix;
+  extraTestScript = ''
+    machine.succeed("mountpoint /");
+  '';
+}