Add delimiter and reusable to arn trait

This commit adds two fields to the aws.api#arn trait:

* resourceDelimiter - used to define the delimiter for resource segments of
absolute ARN templates.
* reusable - indicates whether an ARN may be reused for different instances
of a resource.

docs/Makefile

@@ -7,7 +7,6 @@ SHELL         := /bin/bash
 install: requirements.txt
 	python3 -m venv build/venv
 	source build/venv/bin/activate && pip3 install -r requirements.txt . && pip3 install -e .
-	touch install
 
 clean:
 	-rm -rf build/* install

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

@@ -290,14 +290,25 @@ members:
       - Set to true to specify that the ARN does not contain an account ID.
         If not set, or if set to false, the resolved ARN will contain a
         placeholder for the customer account ID. This can only be set to
-        true if absolute is not set or is false.
+        true if ``absolute`` is not set or is false.
     * - absolute
       - ``boolean``
       - Set to true to indicate that the ARN template contains a fully-formed
         ARN that does not need to be merged with the service. This type of
         ARN MUST be used when the identifier of a resource is an ARN or is
         based on the ARN identifier of a parent resource.
+    * - resourceDelimiter
+      - ``string``
+      - Indicates which character is used to delimit sections of the resource
+        segment of an ARN. This can only be set if ``absolute`` is set to true.
+        Valid values are ``/`` (forward slash) and ``:`` (colon).
+    * - reusable
+      - ``boolean``
+      - Set to true to indicate that an ARN may be reused for different
+        instances of a resource.
+
 
+.. _aws.api#arn-trait_format-of-an-arn:
 
 Format of an ARN
 ================
@@ -354,6 +365,8 @@ Some example ARNs from various services include:
     arn:aws:s3:::my_corporate_bucket/exampleobject.png
 
 
+.. _aws.api#arn-trait_relative-arn-templates:
+
 Relative ARN templates
 ======================
 
@@ -391,6 +404,8 @@ identifier is to be inserted into the ARN template when resolving it at
 runtime.
 
 
+.. _aws.api#arn-trait_using-an-arn-as-a-resource-identifier:
+
 Using an ARN as a resource identifier
 =====================================
 

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/ArnTrait.java

@@ -19,11 +19,13 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import software.amazon.smithy.model.SourceException;
 import software.amazon.smithy.model.node.Node;
 import software.amazon.smithy.model.node.ObjectNode;
+import software.amazon.smithy.model.node.ToNode;
 import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.model.traits.AbstractTrait;
 import software.amazon.smithy.model.traits.AbstractTraitBuilder;
@@ -42,21 +44,27 @@ public final class ArnTrait extends AbstractTrait implements ToSmithyBuilder<Arn
     private static final String ABSOLUTE = "absolute";
     private static final String NO_REGION = "noRegion";
     private static final String NO_ACCOUNT = "noAccount";
+    private static final String RESOURCE_DELIMITER = "resourceDelimiter";
+    private static final String REUSABLE = "reusable";
     private static final Pattern PATTERN = Pattern.compile("\\{([^}]+)}");
 
     private final boolean noRegion;
     private final boolean noAccount;
     private final boolean absolute;
     private final String template;
     private final List<String> labels;
+    private final ResourceDelimiter resourceDelimiter;
+    private final boolean reusable;
 
     private ArnTrait(Builder builder) {
         super(ID, builder.getSourceLocation());
         this.template = SmithyBuilder.requiredState(TEMPLATE, builder.template);
+        this.labels = Collections.unmodifiableList(parseLabels(template));
         this.noRegion = builder.noRegion;
         this.noAccount = builder.noAccount;
         this.absolute = builder.absolute;
-        this.labels = Collections.unmodifiableList(parseLabels(template));
+        this.resourceDelimiter = builder.resourceDelimiter;
+        this.reusable = builder.reusable;
 
         if (template.startsWith("/")) {
             throw new SourceException("Invalid aws.api#arn trait. The template must not start with '/'. "
@@ -77,6 +85,8 @@ public Trait createTrait(ShapeId target, Node value) {
             builder.absolute(objectNode.getBooleanMemberOrDefault(ABSOLUTE));
             builder.noRegion(objectNode.getBooleanMemberOrDefault(NO_REGION));
             builder.noAccount(objectNode.getBooleanMemberOrDefault(NO_ACCOUNT));
+            objectNode.getStringMember(RESOURCE_DELIMITER, builder::resourceDelimiter);
+            builder.reusable(objectNode.getBooleanMemberOrDefault(REUSABLE));
             ArnTrait result = builder.build();
             result.setNodeCache(value);
             return result;
@@ -128,12 +138,26 @@ public String getTemplate() {
     }
 
     /**
-     * @return Returns the label place holder variable names.
+     * @return Returns the label placeholder variable names.
      */
     public List<String> getLabels() {
         return labels;
     }
 
+    /**
+     * @return Returns the resource delimiter for absolute ARNs.
+     */
+    public Optional<ResourceDelimiter> getResourceDelimiter() {
+        return Optional.ofNullable(resourceDelimiter);
+    }
+
+    /**
+     * @return Returns if the ARN may be reused for different instances of a resource.
+     */
+    public boolean isReusable() {
+        return reusable;
+    }
+
     @Override
     protected Node createNode() {
         return Node.objectNodeBuilder()
@@ -142,6 +166,8 @@ protected Node createNode() {
                 .withMember(ABSOLUTE, Node.from(isAbsolute()))
                 .withMember(NO_ACCOUNT, Node.from(isNoAccount()))
                 .withMember(NO_REGION, Node.from(isNoRegion()))
+                .withOptionalMember(RESOURCE_DELIMITER, getResourceDelimiter())
+                .withMember(REUSABLE, Node.from(isReusable()))
                 .build();
     }
 
@@ -151,11 +177,14 @@ public Builder toBuilder() {
                 .sourceLocation(getSourceLocation())
                 .noRegion(isNoRegion())
                 .noAccount(isNoAccount())
-                .template(getTemplate());
+                .absolute(isAbsolute())
+                .template(getTemplate())
+                .resourceDelimiter(resourceDelimiter)
+                .reusable(reusable);
     }
 
     // Due to the defaulting of this trait, equals has to be overridden
-    // so that inconsequential differences in toNode do not effect equality.
+    // so that inconsequential differences in toNode do not affect equality.
     @Override
     public boolean equals(Object other) {
         if (!(other instanceof ArnTrait)) {
@@ -167,13 +196,45 @@ public boolean equals(Object other) {
             return template.equals(oa.template)
                     && absolute == oa.absolute
                     && noAccount == oa.noAccount
-                    && noRegion == oa.noRegion;
+                    && noRegion == oa.noRegion
+                    && resourceDelimiter == oa.resourceDelimiter
+                    && reusable == oa.reusable;
         }
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(toShapeId(), template, absolute, noAccount, noRegion);
+        return Objects.hash(toShapeId(), template, absolute, noAccount, noRegion, resourceDelimiter, reusable);
+    }
+
+    public enum ResourceDelimiter implements ToNode {
+        FORWARD_SLASH("/"),
+        COLON(":");
+
+        private final String value;
+
+        ResourceDelimiter(String value) {
+            this.value = value;
+        }
+
+        static ResourceDelimiter from(String value) {
+            for (ResourceDelimiter delimiter : values()) {
+                if (delimiter.value.equals(value)) {
+                    return delimiter;
+                }
+            }
+            throw new IllegalArgumentException("Invalid delimiter: " + value);
+        }
+
+        @Override
+        public String toString() {
+            return value;
+        }
+
+        @Override
+        public Node toNode() {
+            return Node.from(value);
+        }
     }
 
     /** Builder for {@link ArnTrait}. */
@@ -182,6 +243,8 @@ public static final class Builder extends AbstractTraitBuilder<ArnTrait, Builder
         private boolean noAccount;
         private boolean absolute;
         private String template;
+        private ResourceDelimiter resourceDelimiter;
+        private boolean reusable;
 
         private Builder() {}
 
@@ -209,5 +272,20 @@ public Builder noRegion(boolean noRegion) {
             this.noRegion = noRegion;
             return this;
         }
+
+        public Builder resourceDelimiter(ResourceDelimiter resourceDelimiter) {
+            this.resourceDelimiter = resourceDelimiter;
+            return this;
+        }
+
+        public Builder resourceDelimiter(String resourceDelimiter) {
+            this.resourceDelimiter = ResourceDelimiter.from(resourceDelimiter);
+            return this;
+        }
+
+        public Builder reusable(boolean reusable) {
+            this.reusable = reusable;
+            return this;
+        }
     }
 }

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/ArnTraitValidator.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.aws.traits;
+
+import java.util.ArrayList;
+import java.util.List;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.shapes.ResourceShape;
+import software.amazon.smithy.model.validation.AbstractValidator;
+import software.amazon.smithy.model.validation.ValidationEvent;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * Validates that the `resourceDelimiter` field of the `aws.api#arn` trait
+ * is only used in conjunction with absolute ARNs.
+ */
+@SmithyInternalApi
+public final class ArnTraitValidator extends AbstractValidator {
+    @Override
+    public List<ValidationEvent> validate(Model model) {
+        List<ValidationEvent> events = new ArrayList<>();
+        for (ResourceShape resource : model.getResourceShapesWithTrait(ArnTrait.class)) {
+            ArnTrait trait = resource.expectTrait(ArnTrait.class);
+            if (!trait.isAbsolute() && trait.getResourceDelimiter().isPresent()) {
+                events.add(error(resource, trait, "A `resourceDelimiter` can only be set for an `absolute` ARN."));
+            }
+        }
+        return events;
+    }
+}

smithy-aws-traits/src/main/resources/META-INF/services/software.amazon.smithy.model.validation.Validator

@@ -1,4 +1,5 @@
 software.amazon.smithy.aws.traits.ArnTemplateValidator
+software.amazon.smithy.aws.traits.ArnTraitValidator
 software.amazon.smithy.aws.traits.HttpChecksumTraitValidator
 software.amazon.smithy.aws.traits.SdkServiceIdValidator
 software.amazon.smithy.aws.traits.clientendpointdiscovery.ClientEndpointDiscoveryValidator

smithy-aws-traits/src/main/resources/META-INF/smithy/aws.api.smithy

@@ -38,6 +38,14 @@ structure arn {
     /// for the customer account ID. This can only be set to true if absolute
     /// is not set or is false.
     noAccount: Boolean
+
+    /// Defines which character is used to delimit sections of the resource
+    /// segment of an ARN. This can only be set if absolute is set to true.
+    resourceDelimiter: ResourceDelimiter
+
+    /// Set to true to indicate that an ARN may be reused for different
+    /// instances of a resource.
+    reusable: Boolean
 }
 
 /// Marks a string as containing an ARN.
@@ -262,6 +270,17 @@ structure taggable {
     disableSystemTags: Boolean
 }
 
+
+/// The possible delimiters for an ARN resource segment.
+@private
+enum ResourceDelimiter {
+    /// The `/` character.
+    FORWARD_SLASH = "/"
+
+    /// The `:` character.
+    COLON = ":"
+}
+
 /// A string representing a service's ARN namespace.
 @pattern("^[a-z0-9.\\-]{1,63}$")
 @private

smithy-aws-traits/src/test/java/software/amazon/smithy/aws/traits/ArnIndexTest.java

@@ -34,7 +34,7 @@ public class ArnIndexTest {
     public static void beforeClass() {
         model = Model.assembler()
                 .discoverModels(ArnIndexTest.class.getClassLoader())
-                .addImport(ArnIndexTest.class.getResource("test-model.json"))
+                .addImport(ArnIndexTest.class.getResource("test-model.smithy"))
                 .assemble()
                 .unwrap();
     }
@@ -104,7 +104,7 @@ public void returnsDefaultServiceArnNamespaceForAwsService() {
     public void findsEffectiveArns() {
         Model m = Model.assembler()
                 .discoverModels(ArnIndexTest.class.getClassLoader())
-                .addImport(ArnIndexTest.class.getResource("effective-arns.json"))
+                .addImport(ArnIndexTest.class.getResource("effective-arns.smithy"))
                 .assemble()
                 .unwrap();
         ArnIndex index = ArnIndex.of(m);

smithy-aws-traits/src/test/java/software/amazon/smithy/aws/traits/ArnReferenceTraitTest.java

@@ -76,7 +76,7 @@ public void loadsTraitWithOptionalValuesAndRelativeShapeIds() {
     public void loadsFromModel() {
         Model result = Model.assembler()
                 .discoverModels(getClass().getClassLoader())
-                .addImport(getClass().getResource("test-model.json"))
+                .addImport(getClass().getResource("test-model.smithy"))
                 .assemble()
                 .unwrap();
         Shape service = result.expectShape(ShapeId.from("ns.foo#AbsoluteResourceArn"));

smithy-aws-traits/src/test/java/software/amazon/smithy/aws/traits/ArnTraitTest.java

@@ -46,12 +46,15 @@ public void loadsTraitWithFromNode() {
         assertThat(arnTrait.getTemplate(), equalTo("resourceName"));
         assertThat(arnTrait.isNoAccount(), is(false));
         assertThat(arnTrait.isNoRegion(), is(false));
+        assertThat(arnTrait.isAbsolute(), is(false));
         assertThat(arnTrait.getLabels(), empty());
+        assertThat(arnTrait.getResourceDelimiter().isPresent(), is(false));
+        assertThat(arnTrait.isReusable(), is(false));
     }
 
     @Test
-    public void canSetRegionAndServiceToNo() {
-        Node node = Node.parse("{\"noAccount\": true, \"noRegion\": true, \"absolute\": false, \"template\": \"foo\"}");
+    public void canSetOtherFields() {
+        Node node = Node.parse("{\"noAccount\": true, \"noRegion\": true, \"absolute\": false, \"template\": \"foo\", \"reusable\": true}");
         TraitFactory provider = TraitFactory.createServiceFactory();
         Optional<Trait> trait = provider.createTrait(ArnTrait.ID, ShapeId.from("ns.foo#foo"), node);
 
@@ -60,8 +63,24 @@ public void canSetRegionAndServiceToNo() {
         assertThat(arnTrait.getTemplate(), equalTo("foo"));
         assertThat(arnTrait.isNoAccount(), is(true));
         assertThat(arnTrait.isNoRegion(), is(true));
+        assertThat(arnTrait.isAbsolute(), is(false));
         assertThat(arnTrait.toNode(), equalTo(node));
         assertThat(arnTrait.toBuilder().build(), equalTo(arnTrait));
+        assertThat(arnTrait.isReusable(), is(true));
+    }
+
+    @Test
+    public void canSetAbsoluteAndDelimiter() {
+        Node node = Node.parse("{\"absolute\": true, \"template\": \"foo\", \"resourceDelimiter\": \":\"}");
+        TraitFactory provider = TraitFactory.createServiceFactory();
+        Optional<Trait> trait = provider.createTrait(ArnTrait.ID, ShapeId.from("ns.foo#foo"), node);
+
+        assertTrue(trait.isPresent());
+        ArnTrait arnTrait = (ArnTrait) trait.get();
+        assertThat(arnTrait.getTemplate(), equalTo("foo"));
+        assertThat(arnTrait.toBuilder().build(), equalTo(arnTrait));
+        assertThat(arnTrait.isAbsolute(), is(true));
+        assertThat(arnTrait.getResourceDelimiter().get(), equalTo(ArnTrait.ResourceDelimiter.COLON));
     }
 
     @Test

smithy-aws-traits/src/test/java/software/amazon/smithy/aws/traits/ServiceTraitTest.java

@@ -112,7 +112,7 @@ public void requiresProperServiceShapeToResolveDocId() {
     public void loadsFromModel() {
         Model result = Model.assembler()
                 .discoverModels(getClass().getClassLoader())
-                .addImport(getClass().getResource("test-model.json"))
+                .addImport(getClass().getResource("test-model.smithy"))
                 .assemble()
                 .unwrap();
         ServiceShape service = result