Pass more detailed visit errors to apps to avoid ambiguity

demo/src/main/kotlin/dev/hotwire/turbo/demo/features/web/WebFragment.kt

@@ -10,7 +10,9 @@ import dev.hotwire.turbo.demo.util.SIGN_IN_URL
 import dev.hotwire.turbo.fragments.TurboWebFragment
 import dev.hotwire.turbo.nav.TurboNavGraphDestination
 import dev.hotwire.turbo.views.TurboWebView
+import dev.hotwire.turbo.errors.HttpError
 import dev.hotwire.turbo.visit.TurboVisitAction.REPLACE
+import dev.hotwire.turbo.errors.TurboVisitError
 import dev.hotwire.turbo.visit.TurboVisitOptions
 
 @TurboNavGraphDestination(uri = "turbo://fragment/web")
@@ -58,10 +60,11 @@ open class WebFragment : TurboWebFragment(), NavDestination {
         menuProgress?.isVisible = false
     }
 
-    override fun onVisitErrorReceived(location: String, errorCode: Int) {
-        when (errorCode) {
-            401 -> navigate(SIGN_IN_URL, TurboVisitOptions(action = REPLACE))
-            else -> super.onVisitErrorReceived(location, errorCode)
+    override fun onVisitErrorReceived(location: String, error: TurboVisitError) {
+        if (error is HttpError.ClientError.Unauthorized) {
+            navigate(SIGN_IN_URL, TurboVisitOptions(action = REPLACE))
+        } else {
+            super.onVisitErrorReceived(location, error)
         }
     }
 

demo/src/main/kotlin/dev/hotwire/turbo/demo/features/web/WebHomeFragment.kt

@@ -7,6 +7,7 @@ import android.view.View
 import android.view.ViewGroup
 import dev.hotwire.turbo.demo.R
 import dev.hotwire.turbo.nav.TurboNavGraphDestination
+import dev.hotwire.turbo.errors.TurboVisitError
 
 @TurboNavGraphDestination(uri = "turbo://fragment/web/home")
 class WebHomeFragment : WebFragment() {
@@ -15,7 +16,7 @@ class WebHomeFragment : WebFragment() {
     }
 
     @SuppressLint("InflateParams")
-    override fun createErrorView(statusCode: Int): View {
+    override fun createErrorView(error: TurboVisitError): View {
         return layoutInflater.inflate(R.layout.error_web_home, null)
     }
 

turbo/src/main/kotlin/dev/hotwire/turbo/delegates/TurboWebFragmentDelegate.kt

@@ -21,6 +21,7 @@ import dev.hotwire.turbo.views.TurboView
 import dev.hotwire.turbo.views.TurboWebView
 import dev.hotwire.turbo.visit.TurboVisit
 import dev.hotwire.turbo.visit.TurboVisitAction
+import dev.hotwire.turbo.errors.TurboVisitError
 import dev.hotwire.turbo.visit.TurboVisitOptions
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -158,8 +159,8 @@ internal class TurboWebFragmentDelegate(
     /**
      * Displays the error view that's implemented via [TurboWebFragmentCallback.createErrorView].
      */
-    fun showErrorView(code: Int) {
-        turboView?.addErrorView(callback.createErrorView(code))
+    fun showErrorView(error: TurboVisitError) {
+        turboView?.addErrorView(callback.createErrorView(error))
     }
 
     // -----------------------------------------------------------------------
@@ -205,19 +206,19 @@ internal class TurboWebFragmentDelegate(
         navDestination.fragmentViewModel.setTitle(title())
     }
 
-    override fun onReceivedError(errorCode: Int) {
-        callback.onVisitErrorReceived(location, errorCode)
+    override fun onReceivedError(error: TurboVisitError) {
+        callback.onVisitErrorReceived(location, error)
     }
 
     override fun onRenderProcessGone() {
         navigator.navigate(location, TurboVisitOptions(action = TurboVisitAction.REPLACE))
     }
 
-    override fun requestFailedWithStatusCode(visitHasCachedSnapshot: Boolean, statusCode: Int) {
+    override fun requestFailedWithError(visitHasCachedSnapshot: Boolean, error: TurboVisitError) {
         if (visitHasCachedSnapshot) {
-            callback.onVisitErrorReceivedWithCachedSnapshotAvailable(location, statusCode)
+            callback.onVisitErrorReceivedWithCachedSnapshotAvailable(location, error)
         } else {
-            callback.onVisitErrorReceived(location, statusCode)
+            callback.onVisitErrorReceived(location, error)
         }
     }
 

turbo/src/main/kotlin/dev/hotwire/turbo/errors/HttpError.kt

@@ -0,0 +1,159 @@
+package dev.hotwire.turbo.errors
+
+import android.webkit.WebResourceResponse
+
+/**
+ * Errors representing HTTP status codes received from the server.
+ */
+sealed interface HttpError : TurboVisitError {
+    val statusCode: Int
+    val reasonPhrase: String?
+
+    /**
+     * Errors representing HTTP client errors in the 400..499 range.
+     */
+    sealed interface ClientError : HttpError {
+        data object BadRequest : ClientError {
+            override val statusCode = 400
+            override val reasonPhrase = "Bad Request"
+        }
+
+        data object Unauthorized : ClientError {
+            override val statusCode = 401
+            override val reasonPhrase = "Unauthorized"
+        }
+
+        data object Forbidden : ClientError {
+            override val statusCode = 403
+            override val reasonPhrase = "Forbidden"
+        }
+
+        data object NotFound : ClientError {
+            override val statusCode = 404
+            override val reasonPhrase = "Not Found"
+        }
+
+        data object MethodNotAllowed : ClientError {
+            override val statusCode = 405
+            override val reasonPhrase = "Method Not Allowed"
+        }
+
+        data object NotAccessible : ClientError {
+            override val statusCode = 406
+            override val reasonPhrase = "Not Accessible"
+        }
+
+        data object ProxyAuthenticationRequired : ClientError {
+            override val statusCode = 407
+            override val reasonPhrase = "Proxy Authentication Required"
+        }
+
+        data object RequestTimeout : ClientError {
+            override val statusCode = 408
+            override val reasonPhrase = "Request Timeout"
+        }
+
+        data object Conflict : ClientError {
+            override val statusCode = 409
+            override val reasonPhrase = "Conflict"
+        }
+
+        data object MisdirectedRequest : ClientError {
+            override val statusCode = 421
+            override val reasonPhrase = "Misdirected Request"
+        }
+
+        data object UnprocessableEntity : ClientError {
+            override val statusCode = 422
+            override val reasonPhrase = "Unprocessable Entity"
+        }
+
+        data object PreconditionRequired : ClientError {
+            override val statusCode = 428
+            override val reasonPhrase = "Precondition Required"
+        }
+
+        data object TooManyRequests : ClientError {
+            override val statusCode = 429
+            override val reasonPhrase = "Too Many Requests"
+        }
+
+        data class Other(
+            override val statusCode: Int,
+            override val reasonPhrase: String?
+        ) : ClientError
+    }
+
+    /**
+     * Errors representing HTTP server errors in the 500..599 range.
+     */
+    sealed interface ServerError : HttpError {
+        data object InternalServerError : ServerError {
+            override val statusCode = 500
+            override val reasonPhrase = "Internal Server Error"
+        }
+
+        data object NotImplemented : ServerError {
+            override val statusCode = 501
+            override val reasonPhrase = "Not Implemented"
+        }
+
+        data object BadGateway : ServerError {
+            override val statusCode = 502
+            override val reasonPhrase = "Bad Gateway"
+        }
+
+        data object ServiceUnavailable : ServerError {
+            override val statusCode = 503
+            override val reasonPhrase = "Service Unavailable"
+        }
+
+        data object GatewayTimeout : ServerError {
+            override val statusCode = 504
+            override val reasonPhrase = "Gateway Timeout"
+        }
+
+        data object HttpVersionNotSupported : ServerError {
+            override val statusCode = 505
+            override val reasonPhrase = "Http Version Not Supported"
+        }
+
+        data class Other(
+            override val statusCode: Int,
+            override val reasonPhrase: String?
+        ) : ServerError
+    }
+
+    data class UnknownError(
+        override val statusCode: Int,
+        override val reasonPhrase: String?
+    ) : HttpError
+
+    companion object {
+        fun from(errorResponse: WebResourceResponse): HttpError {
+            return getError(errorResponse.statusCode, errorResponse.reasonPhrase)
+        }
+
+        fun from(statusCode: Int): HttpError {
+            return getError(statusCode, null)
+        }
+
+        private fun getError(statusCode: Int, reasonPhrase: String?): HttpError {
+            if (statusCode in 400..499) {
+                return ClientError::class.sealedSubclasses
+                    .mapNotNull { it.objectInstance }
+                    .firstOrNull { it.statusCode == statusCode }
+                    ?: ClientError.Other(statusCode, reasonPhrase)
+            }
+
+            if (statusCode in 500..599) {
+                return ServerError::class.sealedSubclasses
+                    .map { it.objectInstance }
+                    .firstOrNull { it?.statusCode == statusCode }
+                    ?: ServerError.Other(statusCode, reasonPhrase)
+            }
+
+            return UnknownError(statusCode, reasonPhrase)
+        }
+    }
+}

turbo/src/main/kotlin/dev/hotwire/turbo/errors/LoadError.kt

@@ -0,0 +1,17 @@
+package dev.hotwire.turbo.errors
+
+/**
+ * Errors representing when turbo.js or the native adapter fails
+ * to load on a page.
+ */
+sealed interface LoadError : TurboVisitError {
+    val description: String
+
+    data object NotPresent : LoadError {
+        override val description = "Turbo Not Present"
+    }
+
+    data object NotReady : LoadError {
+        override val description = "Turbo Not Ready"
+    }
+}

turbo/src/main/kotlin/dev/hotwire/turbo/errors/TurboVisitError.kt

@@ -0,0 +1,6 @@
+package dev.hotwire.turbo.errors
+
+/**
+ * Represents all possible errors received when attempting to load a page.
+ */
+sealed interface TurboVisitError