[Bug]: api.updateCategory throws TypeError on any partial update that omits name #8857

What happened?

api.updateCategory(id, fields) throws a TypeError for any partial update that does not include name, even though fields is documented and typed as a partial.

I was trying to move a category into a different group during a category restructure, without changing its name.

• Expected: the category moves to the new group, name untouched.
• Actual: TypeError: Cannot read properties of undefined (reading 'trim')

The same shape breaks a hidden-only update, and any other single-field update that omits name.

Sending the current name unchanged alongside the real change succeeds, which is the workaround I'm using:

await api.updateCategory(categoryId, { group_id: groupId, name: currentName }); // works

How can we reproduce the issue?

1. Open any budget file via @actual-app/api (api.init(...) then api.downloadBudget(...)).
2. Get a valid category id and a valid category-group id, e.g. from await api.getCategories() and await api.getCategoryGroups().
3. Call updateCategory with a partial that omits name:

   await api.updateCategory(categoryId, { group_id: groupId });

4. Expected: resolves; the category is now in the new group with its name unchanged.
   Actual: rejects with TypeError: Cannot read properties of undefined (reading 'trim').
5. Confirm it is the omission of name that matters, by re-running with the name included — this succeeds:

   await api.updateCategory(categoryId, { group_id: groupId, name: currentName });

Nothing is written when it throws: the category is left untouched.

Root cause

updateCategory normalizes name unconditionally, before checking whether it was supplied:

async function updateCategory$1(category) {
  try {
    await updateCategory$2(categoryModel$1.toDb({
      ...category,
      name: category.name.trim()   // <-- throws when `name` was not passed
    }));

The public entry point preserves the absence of the key, so name really is undefined by the time it reaches the trim:

api.updateCategory(id, fields) → handlers["api/category-update"] → { id, ...categoryModel.fromExternal(fields) } → handlers["category-update"] → updateCategory$1.

Verified present in 26.8.1 and still present in 26.9.0 (dist/index.js:118200).

Scope

Category-only — I checked the two sibling handlers and neither has the pattern:

• handlers["api/payee-update"] → payeeModel.fromExternal(fields), no unconditional name access
• updateCategoryGroup$1 → categoryGroupModel$1.toDb(group), no trim

Suggested fix

Only normalize name when it is present, and build the update payload from the keys actually passed rather than a fixed field list:

await updateCategory$2(categoryModel$1.toDb({
  ...category,
  ...(typeof category.name === 'string' ? { name: category.name.trim() } : {}),
}));

Suggested tests

• update group_id only → succeeds, name unchanged
• update hidden only → succeeds, name unchanged
• update name only → succeeds, group unchanged
• update with empty fields {} → clean validation error, not a TypeError

Where are you hosting Actual?

Docker (self-hosted, actualbudget/actual-server 26.8.1)

Operating System

Linux

Additional environment

• @actual-app/api 26.8.1; the offending line also confirmed by inspection in 26.9.0
• Reached via the API, not the web UI, so no browser is involved