Add support for intEnum code generation (#383)

- Update smithy-go-codegen-test with intEnum test
- Add unit test for intEnum shape

codegen/smithy-go-codegen-test/model/main.smithy

@@ -310,6 +310,11 @@ structure ListCitiesInput {
     pageSize: Integer
 }
 
+intEnum SimpleOneZero {
+    ONE  = 1
+    ZERO = 0
+}
+
 @mixin
 structure ListCitiesMixin {
     someEnum: SimpleYesNo,
@@ -318,6 +323,7 @@ structure ListCitiesMixin {
     boxedBool: Boolean,
     defaultNumber: DefaultInteger,
     boxedNumber: Integer,
+    someIntegerEnum: SimpleOneZero
 }
 
 structure ListCitiesOutput with [ListCitiesMixin] {

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/CodegenVisitor.java

@@ -39,6 +39,7 @@
 import software.amazon.smithy.model.knowledge.ServiceIndex;
 import software.amazon.smithy.model.knowledge.TopDownIndex;
 import software.amazon.smithy.model.neighbor.Walker;
+import software.amazon.smithy.model.shapes.IntEnumShape;
 import software.amazon.smithy.model.shapes.OperationShape;
 import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.model.shapes.Shape;
@@ -327,4 +328,10 @@ public Void serviceShape(ServiceShape shape) {
         });
         return null;
     }
+
+    @Override
+    public Void intEnumShape(IntEnumShape shape) {
+        writers.useShapeWriter(shape, writer -> new IntEnumGenerator(symbolProvider, writer, shape).run());
+        return null;
+    }
 }

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/IntEnumGenerator.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.go.codegen;
+
+import java.util.LinkedHashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Logger;
+import software.amazon.smithy.codegen.core.Symbol;
+import software.amazon.smithy.codegen.core.SymbolProvider;
+import software.amazon.smithy.model.shapes.IntEnumShape;
+import software.amazon.smithy.model.shapes.MemberShape;
+import software.amazon.smithy.model.traits.DocumentationTrait;
+import software.amazon.smithy.model.traits.EnumValueTrait;
+import software.amazon.smithy.utils.StringUtils;
+
+/**
+ * Renders intEnums and their constants.
+ */
+final class IntEnumGenerator implements Runnable {
+    private static final Logger LOGGER = Logger.getLogger(IntEnumGenerator.class.getName());
+
+    private final SymbolProvider symbolProvider;
+    private final GoWriter writer;
+    private final IntEnumShape shape;
+
+    IntEnumGenerator(SymbolProvider symbolProvider, GoWriter writer, IntEnumShape shape) {
+        this.symbolProvider = symbolProvider;
+        this.writer = writer;
+        this.shape = shape;
+    }
+
+    @Override
+    public void run() {
+        Symbol symbol = symbolProvider.toSymbol(shape);
+
+        writer.write("type $L int32", symbol.getName()).write("");
+
+        writer.writeDocs(String.format("Enum values for %s", symbol.getName()));
+        Set<String> constants = new LinkedHashSet<>();
+        writer.openBlock("const (", ")", () -> {
+            for (Map.Entry<String, MemberShape> entry : shape.getAllMembers().entrySet()) {
+                StringBuilder labelBuilder = new StringBuilder(symbol.getName());
+                String name = entry.getKey();
+
+                for (String part : name.split("(?U)[\\W_]")) {
+                    if (part.matches(".*[a-z].*") && part.matches(".*[A-Z].*")) {
+                        // Mixed case names should not be changed other than first letter capitalized.
+                        labelBuilder.append(StringUtils.capitalize(part));
+                    } else {
+                        // For all non-mixed case parts title case first letter, followed by all other lower cased.
+                        labelBuilder.append(StringUtils.capitalize(part.toLowerCase(Locale.US)));
+                    }
+                }
+                String label = labelBuilder.toString();
+
+                // If camel-casing would cause a conflict, don't camel-case this enum value.
+                if (constants.contains(label)) {
+                    LOGGER.warning(String.format(
+                            "Multiple enums resolved to the same name, `%s`, using unaltered value for: %s",
+                            label, name));
+                    label = name;
+                }
+                constants.add(label);
+
+                entry.getValue().getTrait(DocumentationTrait.class)
+                    .ifPresent(trait -> writer.writeDocs(trait.getValue()));
+                writer.write("$L $L = $L", label, symbol.getName(),
+                    entry.getValue().expectTrait(EnumValueTrait.class).expectIntValue());
+            }
+        }).write("");
+
+        writer.writeDocs(String.format("Values returns all known values for %s. Note that this can be expanded in the "
+                + "future, and so it is only as up to date as the client.%n%nThe ordering of this slice is not "
+                + "guaranteed to be stable across updates.", symbol.getName()));
+        writer.openBlock("func ($L) Values() []$L {", "}", symbol.getName(), symbol.getName(), () -> {
+            writer.openBlock("return []$L{", "}", symbol.getName(), () -> {
+                for (Map.Entry<String, Integer> entry : shape.getEnumValues().entrySet()) {
+                    writer.write("$L,", entry.getValue());
+                }
+            });
+        });
+    }
+}

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/SymbolVisitor.java

@@ -41,6 +41,7 @@
 import software.amazon.smithy.model.shapes.DocumentShape;
 import software.amazon.smithy.model.shapes.DoubleShape;
 import software.amazon.smithy.model.shapes.FloatShape;
+import software.amazon.smithy.model.shapes.IntEnumShape;
 import software.amazon.smithy.model.shapes.IntegerShape;
 import software.amazon.smithy.model.shapes.ListShape;
 import software.amazon.smithy.model.shapes.LongShape;
@@ -504,4 +505,12 @@ public Symbol memberShape(MemberShape member) {
     public Symbol timestampShape(TimestampShape shape) {
         return symbolBuilderFor(shape, "Time", SmithyGoDependency.TIME).build();
     }
+
+    @Override
+    public Symbol intEnumShape(IntEnumShape shape) {
+        String name = getDefaultShapeName(shape);
+        return symbolBuilderFor(shape, name, typesPackageName)
+                .definitionFile("./types/enums.go")
+                .build();
+    }
 }

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/knowledge/GoPointableIndex.java

@@ -192,7 +192,8 @@ private boolean isShapePointable(Shape shape) {
 
     private boolean isShapeEnum(Shape shape) {
         return shape.getType() == ShapeType.STRING && shape.hasTrait(EnumTrait.class)
-                || shape.getType() == ShapeType.ENUM;
+                || shape.getType() == ShapeType.ENUM
+                || shape.getType() == ShapeType.INT_ENUM;
     }
 
     private boolean isBlobStream(Shape shape) {

codegen/smithy-go-codegen/src/main/resources/software/amazon/smithy/go/codegen/smithy-tests/int-enum-shape-test/expected/changeCardInput.go.struct

@@ -0,0 +1,8 @@
+type ChangeCardInput struct {
+
+	Number types.Number
+
+	Suit types.Suit
+
+	noSmithyDocumentSerde
+}

codegen/smithy-go-codegen/src/main/resources/software/amazon/smithy/go/codegen/smithy-tests/int-enum-shape-test/expected/changeCardOutput.go.struct

@@ -0,0 +1,11 @@
+type ChangeCardOutput struct {
+
+	Number types.Number
+
+	Suit types.Suit
+
+	// Metadata pertaining to the operation's result.
+	ResultMetadata middleware.Metadata
+
+	noSmithyDocumentSerde
+}

codegen/smithy-go-codegen/src/main/resources/software/amazon/smithy/go/codegen/smithy-tests/int-enum-shape-test/int-enum-shape-test.smithy

@@ -0,0 +1,43 @@
+$version: "2.0"
+
+namespace smithy.example
+
+service Example {
+    version: "1.0.0"
+    operations: [
+        ChangeCard
+    ]
+}
+
+operation ChangeCard {
+    input: Card
+    output: Card
+}
+
+structure Card {
+    suit: Suit
+    number: Number
+}
+
+enum Suit {
+    DIAMOND
+    CLUB
+    HEART
+    SPADE
+}
+
+intEnum Number {
+    ACE   = 1
+    TWO   = 2
+    THREE = 3
+    FOUR  = 4
+    FIVE  = 5
+    SIX   = 6
+    SEVEN = 7
+    EIGHT = 8
+    NINE  = 9
+    TEN   = 10
+    JACK  = 11
+    QUEEN = 12
+    KING  = 13
+}

codegen/smithy-go-codegen/src/test/java/software/amazon/smithy/go/codegen/IntEnumShapeGeneratorTest.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.go.codegen;
+
+import java.util.logging.Logger;
+import org.junit.jupiter.api.Test;
+
+import software.amazon.smithy.build.MockManifest;
+import software.amazon.smithy.build.PluginContext;
+import software.amazon.smithy.go.codegen.GoCodegenPlugin;
+import software.amazon.smithy.model.Model;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import static software.amazon.smithy.go.codegen.TestUtils.buildMockPluginContext;
+import static software.amazon.smithy.go.codegen.TestUtils.loadSmithyModelFromResource;
+import static software.amazon.smithy.go.codegen.TestUtils.loadExpectedFileStringFromResource;
+
+
+public class IntEnumShapeGeneratorTest {
+    private static final Logger LOGGER = Logger.getLogger(IntEnumShapeGeneratorTest.class.getName());
+
+    @Test
+    public void testIntEnumShapeTest() {
+
+        // Arrange
+        Model model =
+            loadSmithyModelFromResource("int-enum-shape-test");
+        MockManifest manifest =
+            new MockManifest();
+        PluginContext context =
+            buildMockPluginContext(model, manifest, "smithy.example#Example");
+
+        // Act
+        (new GoCodegenPlugin()).execute(context);
+
+        // Assert
+        String actualEnumShapeCode =
+            manifest.getFileString("types/enums.go").get();
+        String expectedEnumShapeCode =
+            loadExpectedFileStringFromResource("int-enum-shape-test", "types/enums.go");
+        assertThat("intEnum shape actual generated code is equal to the expected generated code",
+            actualEnumShapeCode,
+            is(expectedEnumShapeCode));
+        String actualChangeCardOperationCode =
+            manifest.getFileString("api_op_ChangeCard.go").get();
+        String expectedChangeCardInputCode =
+            loadExpectedFileStringFromResource("int-enum-shape-test", "changeCardInput.go.struct");
+        assertThat("intEnum shape properly referenced in generated input structure code",
+            actualChangeCardOperationCode,
+            containsString(expectedChangeCardInputCode));
+        String expectedChangeCardOutputCode =
+            loadExpectedFileStringFromResource("int-enum-shape-test", "changeCardOutput.go.struct");
+        assertThat("intEnum shape properly referenced in generated output structure code",
+            actualChangeCardOperationCode,
+            containsString(expectedChangeCardOutputCode));
+
+    }
+
+}