fix: Consider an empty string header value to be present

Package.swift

@@ -280,5 +280,9 @@ let package = Package(
  name: "SmithyRetriesTests",
  dependencies: ["ClientRuntime", "SmithyRetriesAPI", "SmithyRetries", "SmithyTestUtil"]
  ),
+ .testTarget(
+ name: "SmithyHTTPAPITests",
+ dependencies: ["SmithyHTTPAPI"]
+ ),
  ].compactMap { $0 }
 )

Sources/SmithyHTTPAPI/Headers.swift

@@ -138,15 +138,7 @@ public struct Headers: Sendable {
  }
 
  public func exists(name: String) -> Bool {
- guard headers.index(of: name) != nil else {
- return false
- }
-
- guard let value = value(for: name) else {
- return false
- }
-
- return !value.isEmpty
+ headers.index(of: name) != nil
  }
 
  /// The dictionary representation of all headers.

Tests/ClientRuntimeTests/NetworkingTests/Http/HttpHeadersTests.swift → Tests/SmithyHTTPAPITests/HeadersTests.swift

@@ -1,13 +1,14 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0.
- */
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
 
 import SmithyHTTPAPI
 import XCTest
-import ClientRuntime
 
-class HttpHeadersTests: XCTestCase {
+class HeadersTests: XCTestCase {
 
  var headersAsDictionaryWithArray = [String: [String]]()
  var headersAsDictionary = [String: String]()
@@ -123,4 +124,21 @@ class HttpHeadersTests: XCTestCase {
  XCTAssertEqual(headerA, headerB)
  XCTAssertEqual(headerA.hashValue, headerB.hashValue)
  }
+
+ // MARK: - exists()
+
+ func test_exists_trueIfHeaderExists() {
+ let subject = Headers(["a": "abc"])
+ XCTAssertTrue(subject.exists(name: "a"))
+ }
+
+ func test_exists_falseIfHeaderDoesntExist() {
+ let subject = Headers(["a": "abc"])
+ XCTAssertFalse(subject.exists(name: "b"))
+ }
+
+ func test_exists_trueIfHeaderValueIsEmptyString() {
+ let subject = Headers(["a": ""])
+ XCTAssertTrue(subject.exists(name: "a"))
+ }
 }