add proguard

android/build.gradle

@@ -29,10 +29,21 @@ android {
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 
         vectorDrawables.useSupportLibrary = true
+        consumerProguardFiles 'proguard-rules.pro'
     }
     lintOptions {
         disable 'InvalidPackage'
     }
+    buildTypes {
+        debug {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+        release {
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
     dependencies {
         implementation 'androidx.webkit:webkit:1.0.0'
         implementation 'androidx.browser:browser:1.0.0'

android/proguard-rules.pro

+# WebView
+-keepattributes *JavascriptInterface*
+-keepclassmembers class * {
+    @android.webkit.JavascriptInterface <methods>;
+}
+-keepclassmembers class * extends android.webkit.WebViewClient {
+    public void *(android.webkit.WebView, java.lang.String, android.graphics.Bitmap);
+    public boolean *(android.webkit.WebView, java.lang.String);
+    public void *(android.webkit.webView, jav.lang.String);
+}
+-keepclassmembers class com.pichillilorenzo.flutter_inappbrowser$JavaScriptBridgeInterface {
+     <fields>;
+     <methods>;
+     public *;
+     private *;
+}
+-keep class com.pichillilorenzo.flutter_inappbrowser.** { *; }
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