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Running the App in Development

Start the full desktop app (Rust backend + Vite dev server) with:

npm run tauri

This runs the tauri dev command configured in package.json, which uses src/core/tauri.conf.json. Under the hood, Tauri starts the Vite dev server (beforeDevCommand) and points the desktop shell's webview at devUrl (http://localhost:8080), then compiles and launches the Rust binary.

Hot reload behavior​

  • Frontend (src/ui/) — Vite + SWC provide fast HMR. Most component/style edits update instantly in the running webview without a full reload.
  • Backend (src/core/) — Rust changes require Tauri to recompile the binary. The dev process detects source changes and rebuilds/restarts automatically; expect a short pause (typically several seconds) for Rust recompilation, longer than frontend HMR.

Opening the webview devtools​

Set the OPEN_DEVTOOLS environment variable to automatically open devtools on startup:

OPEN_DEVTOOLS=true npm run tauri

This is read in the Rust setup hook (src/core/src/lib.rs):

if std::env::var("OPEN_DEVTOOLS").as_deref() == Ok("true") {
    if let Some(window) = app.get_webview_window("main") {
        window.open_devtools();
    }
}

Local SQLite database​

On startup, the Rust backend (src/core/src/database/mod.rs) resolves the platform's app data directory and opens/creates imh.db there, then runs migrations (src/core/src/database/migrations/) and seeds (src/core/src/database/seeds/) automatically:

OSTypical location
macOS~/Library/Application Support/com.openlingua.ieltsmasteryhub/imh.db
Linux~/.local/share/com.openlingua.ieltsmasteryhub/imh.db
Windows%APPDATA%\com.openlingua.ieltsmasteryhub\imh.db

Resetting the database during development​

To start fresh, quit the app and delete the imh.db file (plus any -wal/-shm companion files) at the path above. On the next npm run tauri launch, migrations and seeds will recreate it. See docs/database-reset.md for repo-specific reset notes and CONTRIBUTING.md for how to point sqlx CLI tooling at this same file via DATABASE_URL.

Seed asset (image/audio) copying​

Schema migrations and SQL seed data always run reliably, but copying bundled seed asset files (writing task images, listening audio) into ~/.imh/... resolves its source directory at runtime and can behave differently in tauri dev vs. a packaged build — run with RUST_LOG=info npm run tauri to see exactly which seed source paths were resolved and whether they were found. See Seed asset copying vs. schema migrations and the Troubleshooting page.

Dev architecture at a glance​

graph LR
  A[Vite Dev Server<br/>localhost:8080] -->|HMR| B[React UI in Webview]
  B -->|invoke commands| C[Tauri IPC]
  C --> D[Rust Commands]
  D --> E[Repositories]
  E --> F[(imh.db<br/>SQLite, app_data_dir)]
  G[OPEN_DEVTOOLS=true] -.opens.-> H[Webview Devtools]

Next: Building for Production.