feat: make credentials provider chain accept list of credentials providers (#910)

Author: 0marperez

.changes/493ccb85-b5ab-4a0b-89eb-c4ef45bfcf42.json

@@ -0,0 +1,8 @@
+{
+    "id": "493ccb85-b5ab-4a0b-89eb-c4ef45bfcf42",
+    "type": "feature",
+    "description": "Make CredentialsProviderChain accept list of CredentialProviders",
+    "issues": [
+        "awslabs/aws-sdk-kotlin#1001"
+    ]
+}

runtime/auth/aws-credentials/api/aws-credentials.api

@@ -39,6 +39,7 @@ public abstract interface class aws/smithy/kotlin/runtime/auth/awscredentials/Cr
 }
 
 public final class aws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProviderChain : aws/smithy/kotlin/runtime/identity/IdentityProviderChain, aws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProvider {
+	public fun <init> (Ljava/util/List;)V
 	public fun <init> ([Laws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProvider;)V
 	public fun resolve (Laws/smithy/kotlin/runtime/util/Attributes;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }

runtime/auth/aws-credentials/common/src/aws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProviderChain.kt

@@ -16,5 +16,8 @@ import aws.smithy.kotlin.runtime.util.Attributes
  */
 public class CredentialsProviderChain(vararg providers: CredentialsProvider) :
     IdentityProviderChain<CredentialsProvider, Credentials>(*providers), CredentialsProvider {
+
+    public constructor(providers: List<CredentialsProvider>) : this(*providers.toTypedArray())
+
     override suspend fun resolve(attributes: Attributes): Credentials = super.resolve(attributes)
 }

runtime/auth/aws-credentials/common/test/aws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProviderChainTest.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.auth.awscredentials
+
+import aws.smithy.kotlin.runtime.util.Attributes
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.jupiter.api.Test
+import kotlin.test.assertEquals
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class CredentialsProviderChainTest {
+    private class TestCredentialsProvider(val accessKeyId: String? = null, val secretAccessKey: String? = null) : CredentialsProvider {
+        override suspend fun resolve(attributes: Attributes): Credentials =
+            if (accessKeyId != null && secretAccessKey != null) Credentials(accessKeyId, secretAccessKey) else error("no credentials available")
+    }
+
+    @Test
+    fun testVararg() = runTest {
+        val chain = CredentialsProviderChain(TestCredentialsProvider(), TestCredentialsProvider("AKeyID", "SecretKey"))
+        assertEquals(Credentials("AKeyID", "SecretKey"), chain.resolve())
+    }
+
+    @Test
+    fun testList() = runTest {
+        val credentialsProviders = listOf<CredentialsProvider>(TestCredentialsProvider(), TestCredentialsProvider("AKeyID", "SecretKey"))
+        val chain = CredentialsProviderChain(credentialsProviders)
+        assertEquals(Credentials("AKeyID", "SecretKey"), chain.resolve())
+    }
+}

runtime/auth/http-auth/api/http-auth.api

@@ -37,6 +37,7 @@ public abstract interface class aws/smithy/kotlin/runtime/http/auth/BearerTokenP
 }
 
 public final class aws/smithy/kotlin/runtime/http/auth/BearerTokenProviderChain : aws/smithy/kotlin/runtime/identity/IdentityProviderChain, aws/smithy/kotlin/runtime/http/auth/BearerTokenProvider {
+	public fun <init> (Ljava/util/List;)V
 	public fun <init> ([Laws/smithy/kotlin/runtime/http/auth/BearerTokenProvider;)V
 	public fun resolve (Laws/smithy/kotlin/runtime/util/Attributes;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }

runtime/auth/http-auth/common/src/aws/smithy/kotlin/runtime/http/auth/BearerTokenProviderChain.kt

@@ -18,5 +18,8 @@ import aws.smithy.kotlin.runtime.util.Attributes
 public class BearerTokenProviderChain(vararg providers: BearerTokenProvider) :
     IdentityProviderChain<BearerTokenProvider, BearerToken>(*providers),
     BearerTokenProvider {
+
+    public constructor(providers: List<BearerTokenProvider>) : this(*providers.toTypedArray())
+
     override suspend fun resolve(attributes: Attributes): BearerToken = super.resolve(attributes)
 }

runtime/auth/http-auth/common/test/aws/smithy/kotlin/runtime/http/auth/BearerTokenProviderChainTest.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.http.auth
+
+import aws.smithy.kotlin.runtime.time.Instant
+import aws.smithy.kotlin.runtime.util.Attributes
+import aws.smithy.kotlin.runtime.util.emptyAttributes
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class BearerTokenProviderChainTest {
+    private class TestTokenProvider(val token: String? = null) : BearerTokenProvider {
+        override suspend fun resolve(attributes: Attributes): BearerToken =
+            if (token != null) Token(token) else error("no credentials available")
+    }
+
+    @Test
+    fun testVararg() = runTest {
+        val chain = BearerTokenProviderChain(TestTokenProvider(), TestTokenProvider("token"))
+        assertEquals(Token("token"), chain.resolve())
+    }
+
+    @Test
+    fun testList() = runTest {
+        val tokenProviders = listOf<BearerTokenProvider>(TestTokenProvider(), TestTokenProvider("token"))
+        val chain = BearerTokenProviderChain(tokenProviders)
+        assertEquals(Token("token"), chain.resolve())
+    }
+}
+
+private data class Token(
+    override val token: String,
+    override val attributes: Attributes = emptyAttributes(),
+    override val expiration: Instant? = null,
+) : BearerToken