Sorry but it's still not quite right. I wrote this before: > please use proper types. You can find them in interface AppState and also this before: > We need to define what arguments this function takes, so please either create an interface for props that tells what props are actually used by the function, or create separate arguments for each dependency. But unfortunately you've changed it again and you're now passing the whole application state to the function, making it impossible to know what arguments the function actually needs. As a result, in the tests you are passing "any" for all the variables, so we have no type checks whatsoever. It would help if you could follow my suggestions or if you think what I'm saying makes no sense, let's discuss it, but there's no point changing the code over and over, each new version being as incorrect as the one before.

`export default function ....`

Please remove

`const getWindowTitle = require('./getWindowTitle').default;`

`import getWindowTitle from ./getWindowTitle'`

no need to trim

No need to trim

please use proper types. You can find them in interface AppState

Please remove

Please remove. This directory is now called "Sidebar".

Please remove

Please narrow down the data to just what's needed by getWindowTitle. Also please test other conditions: - No selected notes - No selected folders - When we're not on the Main screen By simplifying the input data it's easier to create multiple tests and they will also be easier to maintain.

We need to define what arguments this function takes, so please either create an interface for `props` that tells what props are actually used by the function, or create separate arguments for each dependency.

We need unit test for this function. Perhaps one way would be to move the function to a separate file `getWindowTitle.ts` and have `getWindowTitle.test.ts` next to it. Please see how other test files are setup within the app-desktop package for more information, and if you need any help let me know.

`_('Untitled')`

Please shorten to this: ``` const note = props.selectedNoteIds.length ? BaseModel.byId(props.notes, props.selectedNoteIds[0]) : null const folder = props.selectedFolderId ? BaseModel.byId(props.folders, selectedFolderId) : null ```

Rename to "props"

Any reason for this "prevTitle" optimisation? Is it slow without it?

I see there's already a `substrWithEllipsis` function in string-utils so please use this.

We don't add derived state to the state because you can get all this at the point where you need it. In fact, please create a "windowTitle()" function that encapsulates that new logic and the existing logic and returns the window title. Having a separate function will also make it easier to unit test it.

I would suggest using a breadcrump: `folderTitle > noteTitle`

How does it handle long titles?