feat: auto retry requests using RetryRequestInterceptor

Author: Guilherme Souza

Sources/Functions/FunctionsClient.swift

@@ -54,7 +54,7 @@ public final class FunctionsClient: Sendable {
     if let logger {
       interceptors.append(LoggerInterceptor(logger: logger))
     }
-
+    interceptors.append(RetryRequestInterceptor.default)
     let http = HTTPClient(fetch: fetch, interceptors: interceptors)
 
     self.init(url: url, headers: headers, region: region, http: http)

Sources/Helpers/HTTP/HTTPHeader.swift

@@ -23,7 +23,7 @@ package struct HTTPHeaders {
   }
 
   package mutating func update(_ field: HTTPHeader) {
-    if let index = fields.firstIndex(where: { $0.name.lowercased() == field.name.lowercased() }) {
+    if let index = fields.firstIndex(where: { $0.canonicalName == field.canonicalName }) {
       fields[index] = field
     } else {
       fields.append(field)
@@ -35,12 +35,12 @@ package struct HTTPHeaders {
   }
 
   package mutating func remove(name: String) {
-    fields.removeAll { $0.name.lowercased() == name.lowercased() }
+    fields.removeAll { $0.canonicalName == name.lowercased() }
   }
 
   package func value(for name: String) -> String? {
     fields
-      .firstIndex(where: { $0.name.lowercased() == name.lowercased() })
+      .firstIndex(where: { $0.canonicalName == name.lowercased() })
       .map { fields[$0].value }
   }
 
@@ -71,6 +71,11 @@ package struct HTTPHeaders {
     return Dictionary(namesAndValues, uniquingKeysWith: { _, last in last })
   }
 
+  var canonicalDictionary: [String: String] {
+    let namesAndValues = fields.map { ($0.canonicalName, $0.value) }
+    return Dictionary(namesAndValues, uniquingKeysWith: { _, last in last })
+  }
+
   package mutating func merge(with other: HTTPHeaders) {
     for field in other.fields {
       update(field)
@@ -137,9 +142,13 @@ package struct HTTPHeader: Sendable, Hashable {
   package let name: String
   package let value: String
 
+  package let canonicalName: String
+
   package init(name: String, value: String) {
     self.name = name
     self.value = value
+
+    canonicalName = name.lowercased()
   }
 }
 
@@ -152,6 +161,6 @@ extension HTTPHeader: CustomStringConvertible {
 
 extension HTTPHeaders: Equatable {
   package static func == (lhs: Self, rhs: Self) -> Bool {
-    lhs.dictionary == rhs.dictionary
+    lhs.canonicalDictionary == rhs.canonicalDictionary
   }
 }

Sources/Helpers/HTTP/RetryRequestInterceptor.swift

@@ -17,6 +17,9 @@ import Foundation
 /// of failure, with exponential backoff between retries. You can configure the retry behavior by specifying
 /// the retry limit, exponential backoff base, scale, retryable HTTP methods, HTTP status codes, and URL error codes.
 package actor RetryRequestInterceptor: HTTPClientInterceptor {
+  /// A ``RetryRequestInterceptor`` instance with default values.
+  package static let `default` = RetryRequestInterceptor()
+
   /// The default retry limit for the interceptor.
   package static let defaultRetryLimit = 2
   /// The default base value for exponential backoff.

Sources/PostgREST/PostgrestBuilder.swift

@@ -31,6 +31,7 @@ public class PostgrestBuilder: @unchecked Sendable {
     if let logger = configuration.logger {
       interceptors.append(LoggerInterceptor(logger: logger))
     }
+    interceptors.append(RetryRequestInterceptor.default)
 
     http = HTTPClient(fetch: configuration.fetch, interceptors: interceptors)
 

Sources/Storage/StorageApi.swift

@@ -21,6 +21,7 @@ public class StorageApi: @unchecked Sendable {
     if let logger = configuration.logger {
       interceptors.append(LoggerInterceptor(logger: logger))
     }
+    interceptors.append(RetryRequestInterceptor.default)
 
     http = HTTPClient(
       fetch: configuration.session.fetch,