add test for resolving env, correctly create attribute

Author: xinsong-cui

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

@@ -7,7 +7,7 @@ package aws.smithy.kotlin.runtime.http.auth
 import aws.smithy.kotlin.runtime.businessmetrics.SmithyBusinessMetric
 import aws.smithy.kotlin.runtime.businessmetrics.emitBusinessMetric
 import aws.smithy.kotlin.runtime.collections.Attributes
-import aws.smithy.kotlin.runtime.collections.toMutableAttributes
+import aws.smithy.kotlin.runtime.collections.mutableAttributes
 import aws.smithy.kotlin.runtime.time.Instant
 import aws.smithy.kotlin.runtime.util.PlatformProvider
 
@@ -23,7 +23,7 @@ public class EnvironmentBearerTokenProvider(
             ?: error("$key environment variable is not set")
         return object : BearerToken {
             override val token: String = bearerToken
-            override val attributes: Attributes = attributes.toMutableAttributes().apply {
+            override val attributes: Attributes = mutableAttributes().apply {
                 emitBusinessMetric(SmithyBusinessMetric.BEARER_SERVICE_ENV_VARS)
             }
             override val expiration: Instant? = null

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

@@ -8,11 +8,24 @@ import kotlin.test.assertFailsWith
 
 class EnvironmentBearerTokenProviderTest {
     @Test
-    fun testResolveWithValidToken() = runTest {
+    fun testResolveFromEnvVar() = runTest {
         val provider = EnvironmentBearerTokenProvider(
             "TEST_TOKEN",
             TestPlatformProvider(
                 env = mutableMapOf("TEST_TOKEN" to "test-env-bearer-token"),
+            ),
+        )
+
+        val token = provider.resolve()
+
+        assertEquals("test-env-bearer-token", token.token)
+    }
+
+    @Test
+    fun testResolveFromSysProps() = runTest {
+        val provider = EnvironmentBearerTokenProvider(
+            "TEST_TOKEN",
+            TestPlatformProvider(
                 props = mutableMapOf("TEST_TOKEN" to "test-sys-props-bearer-token"),
             ),
         )