Add applyUserScriptsChange state helper

Centralize the uploaded/removed user-script state
transition, recording a null removed entry when a
target is cleared so it serializes to null.

Signed-off-by: Mihaela Balutoiu <mbalutoiu@cloudbasesolutions.com>

src/utils/UserScriptUtils.spec.tsx

@@ -0,0 +1,128 @@
+/*
+Copyright (C) 2026  Cloudbase Solutions SRL
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import { applyUserScriptsChange } from "./UserScriptUtils";
+
+import type { InstanceScript } from "@src/@types/Instance";
+
+const script = (over: Partial<InstanceScript>): InstanceScript => ({
+  global: null,
+  instanceId: null,
+  scriptContent: "echo hi",
+  fileName: null,
+  ...over,
+});
+
+const empty = { uploadedScripts: [], removedScripts: [] };
+
+describe("applyUserScriptsChange", () => {
+  it("adds new scripts for a target to uploadedScripts", () => {
+    const win = script({ global: "windows", phase: "replica_first_boot" });
+
+    const next = applyUserScriptsChange(
+      empty,
+      { global: "windows", instanceId: null },
+      [win],
+      false,
+    );
+
+    expect(next.uploadedScripts).toEqual([win]);
+    expect(next.removedScripts).toEqual([]);
+  });
+
+  it("replaces a target's scripts without touching other targets", () => {
+    const linux = script({ global: "linux" });
+    const oldWin = script({ global: "windows", scriptContent: "old" });
+    const newWin = script({ global: "windows", scriptContent: "new" });
+
+    const next = applyUserScriptsChange(
+      { uploadedScripts: [linux, oldWin], removedScripts: [] },
+      { global: "windows", instanceId: null },
+      [newWin],
+      false,
+    );
+
+    expect(next.uploadedScripts).toEqual([linux, newWin]);
+    expect(next.removedScripts).toEqual([]);
+  });
+
+  it("records a null removed entry when clearing a previously-saved target", () => {
+    const win = script({ global: "windows" });
+
+    const next = applyUserScriptsChange(
+      { uploadedScripts: [win], removedScripts: [] },
+      { global: "windows", instanceId: null },
+      [],
+      true,
+    );
+
+    expect(next.uploadedScripts).toEqual([]);
+    expect(next.removedScripts).toEqual([
+      {
+        global: "windows",
+        instanceId: null,
+        scriptContent: null,
+        fileName: null,
+      },
+    ]);
+  });
+
+  it("does not record a removed entry when clearing a never-saved target", () => {
+    const win = script({ global: "windows" });
+
+    const next = applyUserScriptsChange(
+      { uploadedScripts: [win], removedScripts: [] },
+      { global: "windows", instanceId: null },
+      [],
+      false,
+    );
+
+    expect(next.uploadedScripts).toEqual([]);
+    expect(next.removedScripts).toEqual([]);
+  });
+
+  it("does not duplicate the removed entry when clearing twice", () => {
+    const removedWin = script({
+      global: "windows",
+      scriptContent: null,
+    });
+
+    const next = applyUserScriptsChange(
+      { uploadedScripts: [], removedScripts: [removedWin] },
+      { global: "windows", instanceId: null },
+      [],
+      true,
+    );
+
+    expect(next.removedScripts).toHaveLength(1);
+    expect(next.removedScripts[0].global).toBe("windows");
+    expect(next.removedScripts[0].scriptContent).toBeNull();
+  });
+
+  it("matches instance targets by instanceId, independently of globals", () => {
+    const win = script({ global: "windows" });
+    const inst = script({ instanceId: "i-1", scriptContent: "old" });
+    const newInst = script({ instanceId: "i-1", scriptContent: "new" });
+
+    const next = applyUserScriptsChange(
+      { uploadedScripts: [win, inst], removedScripts: [] },
+      { global: null, instanceId: "i-1" },
+      [newInst],
+      false,
+    );
+
+    expect(next.uploadedScripts).toEqual([win, newInst]);
+    expect(next.removedScripts).toEqual([]);
+  });
+});

src/utils/UserScriptUtils.ts

@@ -0,0 +1,52 @@
+/*
+Copyright (C) 2026  Cloudbase Solutions SRL
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import type { InstanceScript, UserScriptTarget } from "@src/@types/Instance";
+
+export type UserScriptsState = {
+  uploadedScripts: InstanceScript[];
+  removedScripts: InstanceScript[];
+};
+
+const matchesTarget = (script: InstanceScript, target: UserScriptTarget) =>
+  target.global
+    ? script.global === target.global
+    : script.instanceId === target.instanceId;
+
+export const applyUserScriptsChange = (
+  prev: UserScriptsState,
+  target: UserScriptTarget,
+  scripts: InstanceScript[],
+  hadExisting: boolean,
+): UserScriptsState => {
+  const uploadedScripts = [
+    ...prev.uploadedScripts.filter(s => !matchesTarget(s, target)),
+    ...scripts,
+  ];
+  let removedScripts = prev.removedScripts.filter(
+    s => !matchesTarget(s, target),
+  );
+  if (scripts.length === 0 && hadExisting) {
+    removedScripts = [
+      ...removedScripts,
+      {
+        global: target.global,
+        instanceId: target.instanceId,
+        scriptContent: null,
+        fileName: null,
+      },
+    ];
+  }
+  return { uploadedScripts, removedScripts };
+};