feat: Add WebView user agent collection

Collect the default WebView user agent string via WebSettings,
which provides browser version and system information useful
for device fingerprinting.

Gracefully handles devices where WebView is unavailable.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: oschwald

device-sdk/src/main/java/com/maxmind/device/collector/DeviceDataCollector.kt

@@ -35,6 +35,7 @@ internal class DeviceDataCollector(private val context: Context) {
     private val networkCollector = NetworkCollector(context)
     private val settingsCollector = SettingsCollector(context)
     private val behaviorCollector = BehaviorCollector(context)
+    private val webViewCollector = WebViewCollector(context)
 
     /**
      * Collects current device data.
@@ -61,7 +62,7 @@ internal class DeviceDataCollector(private val context: Context) {
             // Timezone offset in minutes
             timezoneOffset = TimeZone.getDefault().rawOffset / 60000,
             deviceTime = System.currentTimeMillis(),
-            // Other fields will be populated by dedicated collectors in future commits
+            webViewUserAgent = webViewCollector.collectUserAgent(),
         )
 
     private fun collectBuildInfo(): BuildInfo =

device-sdk/src/main/java/com/maxmind/device/collector/WebViewCollector.kt

@@ -0,0 +1,30 @@
+package com.maxmind.device.collector
+
+import android.content.Context
+import android.webkit.WebSettings
+
+/**
+ * Collects WebView context information.
+ *
+ * Retrieves the default WebView user agent string which provides
+ * browser and system version information.
+ */
+internal class WebViewCollector(
+    private val context: Context,
+) {
+    /**
+     * Collects the default WebView user agent.
+     *
+     * @return User agent string, or null if unavailable
+     */
+    fun collectUserAgent(): String? =
+        try {
+            WebSettings.getDefaultUserAgent(context)
+        } catch (
+            @Suppress("TooGenericExceptionCaught", "SwallowedException")
+            e: Exception,
+        ) {
+            // WebView may not be available on all devices
+            null
+        }
+}

device-sdk/src/test/java/com/maxmind/device/collector/WebViewCollectorTest.kt

@@ -0,0 +1,51 @@
+package com.maxmind.device.collector
+
+import android.content.Context
+import android.webkit.WebSettings
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.mockkStatic
+import io.mockk.unmockkStatic
+import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNull
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+
+internal class WebViewCollectorTest {
+    private lateinit var mockContext: Context
+    private lateinit var collector: WebViewCollector
+
+    @BeforeEach
+    internal fun setUp() {
+        mockContext = mockk(relaxed = true)
+        mockkStatic(WebSettings::class)
+        collector = WebViewCollector(mockContext)
+    }
+
+    @AfterEach
+    internal fun tearDown() {
+        unmockkStatic(WebSettings::class)
+    }
+
+    @Test
+    internal fun `collectUserAgent returns user agent string`() {
+        val expectedUserAgent =
+            "Mozilla/5.0 (Linux; Android 13) AppleWebKit/537.36 " +
+                "(KHTML, like Gecko) Chrome/119.0.0.0 Mobile Safari/537.36"
+        every { WebSettings.getDefaultUserAgent(mockContext) } returns expectedUserAgent
+
+        val result = collector.collectUserAgent()
+
+        assertEquals(expectedUserAgent, result)
+    }
+
+    @Test
+    internal fun `collectUserAgent returns null when WebView unavailable`() {
+        every { WebSettings.getDefaultUserAgent(mockContext) } throws RuntimeException("No WebView")
+
+        val result = collector.collectUserAgent()
+
+        assertNull(result)
+    }
+}