Adding IAM Action name trait to override using the API operation name

docs/source-2.0/aws/aws-iam.rst

@@ -392,6 +392,48 @@ deviates from the :ref:`shape name of the shape ID <shape-id>` of the resource.
         }
     }
 
+.. smithy-trait:: aws.iam#actionName
+.. _aws.iam#actionName-trait:
+
+----------------------------
+``aws.iam#actionName`` trait
+----------------------------
+
+Summary
+    Provides a custom IAM action name.
+Trait selector
+    ``operation``
+Value type
+    ``string``
+
+Operations not annotated with the ``actionName`` trait, default to the
+:ref:`shape name of the shape ID <shape-id>` of the targeted operation.
+
+The following example defines two operations:
+
+* ``OperationA`` is not annotated with the ``actionName`` trait, and
+  resolves the action name of ``OperationA``.
+* ``OperationB`` has the ``actionName`` trait, so has the action
+  name ``OverridingActionName``.
+
+.. code-block:: smithy
+
+    $version: "2"
+
+    namespace smithy.example
+
+    use aws.iam#actionName
+
+    service MyService {
+        version: "2020-07-02"
+        operations: [OperationA, OperationB]
+    }
+
+    operation OperationA {}
+
+    @actionName("OverridingActionName")
+    operation OperationB {}
+
 
 .. _deriving-condition-keys:
 

smithy-aws-iam-traits/src/main/java/software/amazon/smithy/aws/iam/traits/ActionNameTrait.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.aws.iam.traits;
+
+import software.amazon.smithy.model.FromSourceLocation;
+import software.amazon.smithy.model.SourceLocation;
+import software.amazon.smithy.model.shapes.ShapeId;
+import software.amazon.smithy.model.traits.StringTrait;
+
+public final class ActionNameTrait extends StringTrait {
+
+    public static final ShapeId ID = ShapeId.from("aws.iam#actionName");
+
+    private ActionNameTrait(String action) {
+        super(ID, action, SourceLocation.NONE);
+    }
+
+    private ActionNameTrait(String action, FromSourceLocation sourceLocation) {
+        super(ID, action, sourceLocation);
+    }
+
+    public static final class Provider extends StringTrait.Provider<ActionNameTrait> {
+        public Provider() {
+            super(ID, ActionNameTrait::new);
+        }
+    }
+}

smithy-aws-iam-traits/src/main/resources/META-INF/services/software.amazon.smithy.model.traits.TraitService

@@ -5,3 +5,4 @@ software.amazon.smithy.aws.iam.traits.DisableConditionKeyInferenceTrait$Provider
 software.amazon.smithy.aws.iam.traits.RequiredActionsTrait$Provider
 software.amazon.smithy.aws.iam.traits.SupportedPrincipalTypesTrait$Provider
 software.amazon.smithy.aws.iam.traits.IamResourceTrait$Provider
+software.amazon.smithy.aws.iam.traits.ActionNameTrait$Provider

smithy-aws-iam-traits/src/main/resources/META-INF/smithy/aws.iam.json

@@ -264,6 +264,18 @@
                 "smithy.api#private": {},
                 "smithy.api#documentation": "An IAM policy principal type."
             }
+        },
+        "aws.iam#actionName": {
+            "type": "string",
+            "member": {
+                "target": "aws.iam#IamIdentifier"
+            },
+            "traits": {
+                "smithy.api#trait": {
+                    "selector": "operation"
+                },
+                "smithy.api#documentation": "Provides a custom IAM action name. By default, the action name is the same as the operation name."
+            }
         }
     }
 }

smithy-aws-iam-traits/src/test/java/software/amazon/smithy/aws/iam/traits/ActionNameTraitTest.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.aws.iam.traits;
+
+import org.junit.jupiter.api.Test;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.shapes.ShapeId;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+public class ActionNameTraitTest {
+    @Test
+    public void loadsFromModel() {
+        Model result = Model.assembler()
+                .discoverModels(getClass().getClassLoader())
+                .addImport(getClass().getResource("actionname-override.smithy"))
+                .assemble()
+                .unwrap();
+
+        Shape shape = result.expectShape(ShapeId.from("smithy.example#Echo"));
+        ActionNameTrait trait = shape.expectTrait(ActionNameTrait.class);
+        assertThat(trait.getValue(), equalTo("overridingActionName"));
+    }
+}

smithy-aws-iam-traits/src/test/resources/software/amazon/smithy/aws/iam/traits/actionname-override.smithy

@@ -0,0 +1,16 @@
+$version: "2.0"
+namespace smithy.example
+
+@aws.iam#actionName("overridingActionName")
+operation Echo {}
+
+operation GetResource2 {
+    input: GetResource2Input
+}
+
+structure GetResource2Input {
+    id1: String,
+
+    @required
+    id2: String
+}