Adding helper for profile credential provider that allows passing pro…

…file name to create.

Seemed like a common enough use-case to warrant a helper method.

.changes/next-release/feature-AWSSDKforJava-f236f16.json

@@ -0,0 +1,5 @@
+{
+    "category": "AWS SDK for Java", 
+    "type": "feature", 
+    "description": "Added `ProfileCredentialsProvider.create(\"profile-name\")` helper to `ProfileCredentialsProvider` to account for common use-case where only profile name is provided."
+}

core/src/main/java/software/amazon/awssdk/core/auth/ProfileCredentialsProvider.java

@@ -59,7 +59,16 @@ private ProfileCredentialsProvider(Builder builder) {
      * defining a custom {@link ProfileCredentialsProvider}.
      */
     public static ProfileCredentialsProvider create() {
-        return new ProfileCredentialsProvider(builder());
+        return builder().build();
+    }
+
+    /**
+     * Create a {@link ProfileCredentialsProvider} using the given profileName and default configuration file. Use
+     * {@link #builder()} for defining a custom {@link ProfileCredentialsProvider}.
+     * @param profileName the name of the profile from the default configuraiton file to use
+     */
+    public static ProfileCredentialsProvider create(String profileName) {
+        return builder().profileName(profileName).build();
     }
 
     /**

core/src/test/java/software/amazon/awssdk/core/auth/ProfileCredentialsProviderTest.java

@@ -15,6 +15,9 @@
 
 package software.amazon.awssdk.core.auth;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static software.amazon.awssdk.core.AwsSystemSetting.AWS_CONFIG_FILE;
+
 import java.io.File;
 import java.lang.reflect.Field;
 import java.util.Map;
@@ -25,6 +28,7 @@
 import software.amazon.awssdk.core.SdkClientException;
 import software.amazon.awssdk.core.auth.profile.ProfileResourceLoader;
 import software.amazon.awssdk.core.auth.profile.ProfilesConfigFile;
+import software.amazon.awssdk.testutils.EnvironmentVariableHelper;
 
 public class ProfileCredentialsProviderTest {
     private static File profileLocation = null;
@@ -228,6 +232,16 @@ public void testAssumeRoleWithSourceAfterRole() throws Exception {
         Assert.assertEquals("sessionSecretKey", credentials.secretAccessKey());
     }
 
+    @Test
+    public void testProfileNameSimpleMethod() throws Exception {
+        EnvironmentVariableHelper.run(helper -> {
+            helper.set(AWS_CONFIG_FILE, profileLocation.getAbsolutePath());
+            assertThatThrownBy(() -> ProfileCredentialsProvider.create("non-existent-profile").getCredentials())
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("non-existent-profile");
+        });
+    }
+
     @SuppressWarnings("unchecked")
     private Map<String, String> getMutableSystemEnvironment() throws Exception {
         Map<String, String> immutableEnv = System.getenv();

test/test-utils/src/main/java/software/amazon/awssdk/testutils/EnvironmentVariableHelper.java

@@ -21,6 +21,7 @@
 import java.security.PrivilegedExceptionAction;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.function.Consumer;
 import org.junit.rules.ExternalResource;
 import software.amazon.awssdk.utils.SystemSetting;
 
@@ -90,4 +91,30 @@ private PrivilegedExceptionAction<Void> setAccessible(Field f) {
             return null;
         };
     }
+
+    /**
+     * Static run method that allows for "single-use" environment variable modification.
+     *
+     * Example use:
+     * <pre>
+     * <code>
+     * EnvironmentVariableHelper.run(helper -> {
+     *    helper.set("variable", "value");
+     *    //run some test that uses "variable"
+     * });
+     * </code>
+     * </pre>
+     *
+     * Will call {@link #reset} at the end of the block (even if the block exits exceptionally).
+     *
+     * @param helperConsumer a code block to run that gets an {@link EnvironmentVariableHelper} as an argument
+     */
+    public static void run(Consumer<EnvironmentVariableHelper> helperConsumer) {
+        EnvironmentVariableHelper helper = new EnvironmentVariableHelper();
+        try {
+            helperConsumer.accept(helper);
+        } finally {
+            helper.reset();
+        }
+    }
 }

test/test-utils/src/test/java/software/amazon/awssdk/testutils/EnvironmentVariableHelperTest.java

@@ -16,32 +16,56 @@
 package software.amazon.awssdk.testutils;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.mockito.Mockito.*;
 
 import java.util.HashMap;
 import java.util.Map;
-import org.junit.After;
 import org.junit.AfterClass;
-import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.RuleChain;
+import org.junit.experimental.runners.Enclosed;
+import org.junit.runner.RunWith;
 
+@RunWith(Enclosed.class)
 public class EnvironmentVariableHelperTest {
 
     private static Map<String, String> environmentVariables = new HashMap<>(System.getenv());
 
-    @Rule
-    public EnvironmentVariableHelper helper = new EnvironmentVariableHelper();
-
     @AfterClass
     public static void ensureCleanup() {
         assertThat(System.getenv()).hasSameSizeAs(environmentVariables).containsAllEntriesOf(environmentVariables);
     }
 
-    @Test
-    public void helperAsRuleIsResetAfterEachUse() {
-        helper.set("yo yo yo", "blah");
+    public static class Normal {
+        @Test
+        public void testCanUseStaticRun() {
+            assertThat(System.getenv("hello")).isEqualTo(null);
+            EnvironmentVariableHelper.run(helper -> {
+                helper.set("hello", "world");
+                assertThat(System.getenv("hello")).isEqualTo("world");
+            });
+            assertThat(System.getenv("hello")).isEqualTo(null);
+        }
+
+        @Test
+        public void testCanManuallyReset() {
+            EnvironmentVariableHelper helper = new EnvironmentVariableHelper();
+            assertThat(System.getenv("hello")).isEqualTo(null);
+            helper.set("hello", "world");
+            assertThat(System.getenv("hello")).isEqualTo("world");
+            helper.reset();
+            assertThat(System.getenv("hello")).isEqualTo(null);
+        }
+    }
+
+    public static class AsRule {
+
+        @Rule
+        public EnvironmentVariableHelper helper = new EnvironmentVariableHelper();
+
+        @Test
+        public void helperAsRuleIsResetAfterEachUse() {
+            helper.set("yo yo yo", "blah");
+        }
+
     }
 }