ente/web/docs/dependencies.md

# Dependencies

## Dev

These are some global dev dependencies in the root `package.json`. These set the
baseline for how our code be in all the workspaces in this (yarn) monorepo.

- [prettier](https://prettier.io) - Formatter

- [eslint](https://eslint.org) - Linter

- [typescript](https://www.typescriptlang.org/) - Type checker

They also need some support packages, which come from the leaf `@/build-config`
package:

- [@eslint/js](https://eslint.org/) provides JavaScript ESLint functionality,
  and provides the configuration recommended the by ESLint team.

- [typescript-eslint](https://typescript-eslint.io/packages/typescript-eslint/)
  \- provides TypeScript ESLint functionality and provides a set of recommended
  configurations (`typescript-eslint` is the new entry point, our yet-unmigrated
  packages use the older method of separately including
  [@typescript-eslint/parser](https://typescript-eslint.io/packages/eslint-plugin/)
  \- which tells ESLint how to read TypeScript syntax - and
  [@typescript-eslint/eslint-plugin](https://typescript-eslint.io/packages/eslint-plugin/)
  \- which provides the TypeScript rules and presets).

- [eslint-plugin-react](https://github.com/jsx-eslint/eslint-plugin-react),
  [eslint-plugin-react-hooks](https://reactjs.org/) \- Some React specific
  ESLint rules and configurations that are used by the workspaces that have
  React code.

- [eslint-plugin-react-refresh](https://github.com/ArnaudBarre/eslint-plugin-react-refresh)
  \- A plugin to ensure that React components are exported in a way that they
  can be HMR-ed.

- [prettier-plugin-organize-imports](https://github.com/simonhaenisch/prettier-plugin-organize-imports)
  \- A Prettier plugin to sort imports.

- [prettier-plugin-packagejson](https://github.com/matzkoh/prettier-plugin-packagejson)
  \- A Prettier plugin to also prettify `package.json`.

The root `package.json` also has a convenience dev dependency:

- [concurrently](https://github.com/open-cli-tools/concurrently) for spawning
  parallel tasks when we invoke various yarn scripts.

## Cryptography

We use [libsodium](https://libsodium.gitbook.io/doc/) for our cryptography
primitives. We use its WebAssembly target, accessible via JavaScript wrappers
maintained by the original authors of libsodium themselves -
[libsodium-wrappers](https://github.com/jedisct1/libsodium.js).

More precisely, we use the sumo variant, "libsodium-wrappers-sumo", since the
standard variant does not provide the `crypto_pwhash_*` functions.

## Meta frameworks

### Next.js

[Next.js](https://nextjs.org) (package:
[next](https://github.com/vercel/next.js)) provides the meta framework for both
the photos and the auth app, and also for some of the sidecar apps like accounts
and cast.

We use a limited subset of Next.js. The main thing we get out of it is a
reasonable set of defaults for bundling our app into a static export which we
can then deploy to our webserver. In addition, the Next.js page router is
convenient. Overall our apps can be described as regular React SPAs, and are not
particularly tied to Next.js.

### Vite

For some of our newer code, we have started to use [Vite](https://vitejs.dev).
It is likely the future (both generally, and for our code) since Next.js is
becoming less suitable for SPAs and static SSR with their push towards RSC and
dynamic SSR.

## UI

### React

[React](https://react.dev) (package: [react](https://github.com/facebook/react))
is our core framework. We also import its a sibling
[react-dom](https://github.com/facebook/react) package that renders JSX to the
DOM.

> [!NOTE]
>
> We need to repeat the dependency on react and its siblings in multiple
> package.jsons to avoid the unmet peer dependency warnings printed by yarn.
> Ideally, the react dependencies can be specified just in the _@/base_ package.

### MUI and Material Icons

We use [MUI](https://mui.com)'s
[@mui/material](https://mui.com/material-ui/getting-started/installation/) as
our base React component library (In our code and documentation, we use the name
"MUI" to refer to the the combination of both MUI's "Material UI" and "System"
packages that we use).

MUI uses [Emotion](https://emotion.sh/) as its preferred CSS-in-JS library, for
which we need to install install two Emotion packages (`@emotion/react` and
`@emotion/styled`) as peer dependencies.

We also use MUI's
[@mui/material-icons](https://mui.com/material-ui/material-icons/) package,
which provides Material icons exported as React components (a `SvgIcon`).

> [!NOTE]
>
> For a similar reason as with react,
>
> - the `@mui/material` dependency is also repeated at more places - the one in
>   _@/base_ is the canonical one.
> - we need to add an explicit dependency to `mui/system` in _@/new_ even though
>   we don't directly depend on it.

### Date pickers

[@mui/x-date-pickers](https://mui.com/x/react-date-pickers/getting-started/) is
used to get a date/time picker component. This is the community version of the
DateTimePicker component provided by MUI.

[dayjs](https://github.com/iamkun/dayjs) is used as the date library that that
`@mui/x-date-pickers` will internally use to manipulate dates.

### Translations

For showing the app's UI in multiple languages, we use the
[i18next](https://www.i18next.com), specifically its three components

- [i18next](https://github.com/i18next/i18next): The core `i18next` library.
- [react-i18next](https://github.com/i18next/react-i18next): React specific
  support in `i18next`.
- [i18next-http-backend](https://github.com/i18next/i18next-http-backend): Adds
  support for initializing `i18next` with JSON file containing the translation
  in a particular language, fetched at runtime.

Note that inspite of the "next" in the name of the library, it has nothing to do
with Next.js.

For more details, see [translations.md](translations.md).

### Font

Inter Variable (with support for weights 100 - 90) is used as the primary font,
via [@fontsource-variable/inter](https://fontsource.org/fonts/inter/install).

### UI components

- [react-window](https://github.com/bvaughn/react-window) is used for lazy-ily
  rendering large lists of dynamically created content, each item being of a
  variable height. It is usually used in tandem with its sibling package,
  [react-virtualized-auto-sizer](https://github.com/bvaughn/react-virtualized-auto-sizer)
  which allows the lazy list to resize itself automatically to fill the entire
  remaining space available in the container.

- [formik](https://github.com/jaredpalmer/formik) provides an easier to use
  abstraction for dealing with form state, validation and submission states when
  using React.

- [react-select](https://react-select.com/) is used for search dropdowns.

- [react-otp-input](https://github.com/devfolioco/react-otp-input) is used to
  render a segmented OTP input field for 2FA authentication.

## Utilities

- [comlink](https://github.com/GoogleChromeLabs/comlink) provides a minimal
  layer on top of web workers to make them more easier to use.

- [idb](https://github.com/jakearchibald/idb) provides a promise API over the
  browser-native IndexedDB APIs.

    > For more details about IDB and its role, see [storage.md](storage.md).

- [zod](https://github.com/colinhacks/zod) is used for runtime typechecking
  (e.g. verifying that API responses match the expected TypeScript shape).

- [nanoid](https://github.com/ai/nanoid) is used for generating unique
  identifiers. For one particular use case, we also need
  [uuid](https://github.com/uuidjs/uuid) for UUID v4 generation.

- [bs58](https://github.com/cryptocoinjs/bs58) is used for base-58 conversion
  (used for encoding the collection key to use as the hash in the share URL).

- [debounce](https://github.com/sindresorhus/debounce) and its
  promise-supporting sibling
  [pDebounce](https://github.com/sindresorhus/p-debounce) are used for
  debouncing operations (See also: `[Note: Throttle and debounce]`).

- [zxcvbn](https://github.com/dropbox/zxcvbn) is used for password strength
  estimation.

## Media

- [ffmpeg.wasm](https://github.com/ffmpegwasm/ffmpeg.wasm) is used to run FFmpeg
  in the browser using WebAssembly (Wasm). Note that this is substantially
  slower than native ffmpeg (the desktop app can, and does, bundle the faster
  native ffmpeg implementation too).

- [ExifReader](https://github.com/mattiasw/ExifReader) is used for Exif parsing.

- [jszip](https://github.com/Stuk/jszip) is used for reading zip files in the
  web code (Live photos are zip files under the hood). Note that the desktop app
  uses also has a ZIP parser (that one supports streaming).

- [file-type](https://github.com/sindresorhus/file-type) is used for MIME type
  detection. We are at an old version 16.5.4 because v17 onwards the package
  became ESM only - for our limited use case, the custom Webpack configuration
  that it'd entail is not worth the upgrade.

- [heic-convert](https://github.com/catdad-experiments/heic-convert) is used for
  converting HEIC files (which browsers don't natively support) into JPEG. For
  (much more) details, see [heic.md](heic.md).

## Photos app specific

- [react-dropzone](https://github.com/react-dropzone/react-dropzone/) is a React
  hook to create a drag-and-drop input zone. Note that we pin to the last
  version in the 14.2 series, since if we use 14.3 onwards (I tested till
  14.3.5) then we are unable to get back a path from the file by using the
  `webUtils.getPathForFile` function provided by Electron.

- [sanitize-filename](https://github.com/parshap/node-sanitize-filename) is for
  converting arbitrary strings into strings that are suitable for being used as
  filenames.

- [chrono-node](https://github.com/wanasit/chrono) is used for parsing natural
  language queries into dates for showing search results.

- [matrix](https://github.com/mljs/matrix) is mathematical matrix abstraction by
  the machine learning code. It is used alongwith
  [similarity-transformation](https://github.com/shaileshpandit/similarity-transformation-js)
  during face alignment.

- [react-top-loading-bar](https://github.com/klendi/react-top-loading-bar) is
  used for showing a progress indicator for global actions (This shouldn't be
  used always, it is only meant as a fallback when there isn't an otherwise
  suitable place for showing a local activity indicator).

## Auth app specific

- [otpauth](https://github.com/hectorm/otpauth) is used for the generation of
  the actual OTP from the user's TOTP/HOTP secret.

- However, otpauth doesn't support steam OTPs. For these, we need to compute the
  SHA-1, and we use the same library, `jssha` that `otpauth` uses since it is
  already part of our bundle (transitively).