docs: Add Biometric Plugin documentation (#2395)

Co-authored-by: Lucas Nogueira <lucas@tauri.studio>

Author: naman-crabnebula

src/content/docs/plugin/biometric.mdx

@@ -1,22 +1,205 @@
 ---
 title: Biometric
 description: Prompt the user for biometric authentication on Android and iOS.
-sidebar:
-  badge:
-    text: WIP
-    variant: caution
 ---
 
-import Stub from '@components/Stub.astro';
 import PluginLinks from '@components/PluginLinks.astro';
+import { Tabs, TabItem, Steps } from '@astrojs/starlight/components';
+import CommandTabs from '@components/CommandTabs.astro';
 import PluginPermissions from '@components/PluginPermissions.astro';
 
 <PluginLinks plugin="biometric" />
 
-<Stub>
+Prompt the user for biometric authentication on Android and iOS.
 
-Based on https://github.com/tauri-apps/plugins-workspace/tree/plugins/biometric
+## Supported Platforms
 
-</Stub>
+- Android
+- iOS
+
+## Setup
+
+Install the biometric plugin to get started.
+
+<Tabs>
+    <TabItem label="Automatic">
+
+    Use your project's package manager to add the dependency:
+
+    <CommandTabs npm="npm run tauri add biometric"
+    yarn="yarn run tauri add biometric"
+    pnpm="pnpm tauri add biometric"
+    bun="bun tauri add biometric"
+    cargo="cargo tauri add biometric" />
+
+    </TabItem>
+    <TabItem label="Manual">
+        <Steps>
+        1.  Install the biometric plugin by adding the following to your `Cargo.toml` file:
+
+            ```toml title="src-tauri/Cargo.toml"
+            [dependencies]
+            tauri-plugin-biometric = "2.0.0-beta"
+            # alternatively with Git:
+            tauri-plugin-biometric = { git = "https://github.com/tauri-apps/plugins-workspace", branch = "v2" }
+            ```
+
+        2.  Modify `lib.rs` to initialize the plugin:
+
+            ```rust title="src-tauri/src/lib.rs" ins={4}
+            #[cfg_attr(mobile, tauri::mobile_entry_point)]
+            fn run() {
+                tauri::Builder::default()
+                    .plugin(tauri_plugin_biometric::Builder::new().build())
+                    .run(tauri::generate_context!())
+                    .expect("error while running tauri application");
+            }
+            ```
+
+        3.  Install the JavaScript Guest bindings using your preferred JavaScript package manager:
+
+            <CommandTabs
+            npm = "npm install @tauri-apps/plugin-biometric"
+            yarn = "yarn add @tauri-apps/plugin-biometric"
+            pnpm = "pnpm add @tauri-apps/plugin-biometric"
+            bun = "bun add @tauri-apps/plugin-biometric"
+            />
+        </Steps>
+    </TabItem>
+
+</Tabs>
+
+## Usage
+
+This plugin enables you to verify the availability of Biometric Authentication on a device, prompt the user for biometric authentication, and check the result to determine if the authentication was successful or not.
+
+### Check Status
+
+You can check the status of Biometric Authentication, including its availability and the types of biometric authentication methods supported.
+
+<Tabs>
+<TabItem label="JavaScript">
+
+```javascript
+import { checkStatus } from '@tauri-apps/plugin-biometric';
+
+const status = await checkStatus();
+if (status.isAvailable) {
+  console.log('Yes! Biometric Authentication is available');
+} else {
+  console.log(
+    'No! Biometric Authentication is not available due to ' + status.error
+  );
+}
+```
+
+</TabItem>
+<TabItem label="Rust">
+
+```rust
+use tauri_plugin_biometric::BiometricExt;
+
+fn check_biometric(app_handle: tauri::AppHandle) {
+    let status = app_handle.biometric().status().unwrap();
+    if status.is_available {
+        println!("Yes! Biometric Authentication is available");
+    } else {
+        println!("No! Biometric Authentication is not available due to: {}", status.error.unwrap());
+    }
+}
+```
+
+</TabItem>
+</Tabs>
+
+### Authenticate
+
+To prompt the user for Biometric Authentication, utilize the `authenticate()` method.
+
+<Tabs>
+
+<TabItem label="JavaScript">
+
+```javascript ins={18}
+import { authenticate } from '@tauri-apps/plugin-biometric';
+
+const options = {
+  // Set true if you want the user to be able to authenticate using phone password
+  allowDeviceCredential: false,
+  cancelTitle: "Feature won't work if Canceled",
+
+  // iOS only feature
+  fallbackTitle: 'Sorry, authentication failed',
+
+  // Android only features
+  title: 'Tauri feature',
+  subtitle: 'Authenticate to access the locked Tauri function',
+  confirmationRequired: true,
+};
+
+try {
+  await authenticate('This feature is locked', options);
+  console.log(
+    'Hooray! Successfully Authenticated! We can now perform the locked Tauri function!'
+  );
+} catch (err) {
+  console.log('Oh no! Authentication failed because ' + err.message);
+}
+```
+
+</TabItem>
+
+<TabItem label="Rust">
+
+```rust ins={21}
+use tauri_plugin_biometric::{BiometricExt, AuthOptions};
+
+fn bio_auth(app_handle: tauri::AppHandle) {
+
+    let options = AuthOptions {
+        // Set True if you want the user to be able to authenticate using phone password
+        allow_device_credential:false,
+        cancel_title: Some("Feature won't work if Canceled".to_string()),
+
+        // iOS only feature
+        fallback_title: Some("Sorry, authentication failed".to_string()),
+
+        // Android only features
+        title: Some("Tauri feature".to_string()),
+        subtitle: Some("Authenticate to access the locked Tauri function".to_string()),
+        confirmation_required: Some(true),
+    };
+
+    // if the authentication was succesfull, the function returns Result::Ok()
+    // otherwise returns Result::Error()
+    match app_handle.biometric().authenticate("This feature is locked".to_string(), options) {
+        Ok(_) => {
+            println!("Hooray! Successfully Authenticated! We can now perform the locked Tauri function!");
+        }
+        Err(e) => {
+            println!("Oh no! Authentication failed because : {e}");
+        }
+    }
+}
+```
+
+</TabItem>
+</Tabs>
+
+## Permissions
+
+By default all potentially dangerous plugin commands and scopes are blocked and cannot be accessed. You must modify the permissions in your `capabilities` configuration to enable these.
+
+See the [Capabilities Overview](/security/capabilities/) for more information and the [step by step guide](/learn/security/using-plugin-permissions/) to use plugin permissions.
+
+```json title="src-tauri/capabilities/main.json" ins={6}
+{
+  "$schema": "../gen/schemas/desktop-schema.json",
+  "identifier": "main-capability",
+  "description": "Capability for the main window",
+  "windows": ["main"],
+  "permissions": ["biometric:default"]
+}
+```
 
 <PluginPermissions plugin="biometric" />