Add utility to fill shapes with random values

aws/aws-event-streams/src/main/java/software/amazon/smithy/java/aws/events/AwsEventShapeEncoder.java

@@ -18,8 +18,8 @@
 import software.amazon.eventstream.Message;
 import software.amazon.smithy.java.core.error.ModeledException;
 import software.amazon.smithy.java.core.schema.Schema;
-import software.amazon.smithy.java.core.schema.SchemaUtils;
 import software.amazon.smithy.java.core.schema.SerializableStruct;
+import software.amazon.smithy.java.core.schema.ShapeUtils;
 import software.amazon.smithy.java.core.schema.TraitKey;
 import software.amazon.smithy.java.core.serde.Codec;
 import software.amazon.smithy.java.core.serde.ShapeSerializer;
@@ -75,7 +75,7 @@ private byte[] encodeInput(
             typeHolder.set(initialEventType.value());
             var os = new ByteArrayOutputStream();
             try (var baseSerializer = possibleTypes.get(initialEventType.value()).apply(os, headers)) {
-                SchemaUtils.withFilteredMembers(item.schema(), item, AwsEventShapeEncoder::excludeEventStreamMember)
+                ShapeUtils.withFilteredMembers(item.schema(), item, AwsEventShapeEncoder::excludeEventStreamMember)
                         .serialize(baseSerializer);
             }
             return os.toByteArray();
@@ -202,14 +202,14 @@ public EventSerializer(EventHeaderSerializer headerSerializer, ShapeSerializer b
         @Override
         public void writeStruct(Schema schema, SerializableStruct struct) {
             if (hasEventPayloadMember(schema)) {
-                SchemaUtils.withFilteredMembers(schema, struct, this::isEventPayload)
+                ShapeUtils.withFilteredMembers(schema, struct, this::isEventPayload)
                         .serializeMembers(baseSerializer);
 
             } else {
-                SchemaUtils.withFilteredMembers(schema, struct, this::isPayloadMember)
+                ShapeUtils.withFilteredMembers(schema, struct, this::isPayloadMember)
                         .serialize(baseSerializer);
             }
-            SchemaUtils.withFilteredMembers(schema, struct, this::isHeadersMember)
+            ShapeUtils.withFilteredMembers(schema, struct, this::isHeadersMember)
                     .serialize(headerSerializer);
         }
 

client/client-core/src/main/java/software/amazon/smithy/java/client/core/pagination/PaginationInputSetter.java

@@ -7,8 +7,8 @@
 
 import software.amazon.smithy.java.core.schema.ApiOperation;
 import software.amazon.smithy.java.core.schema.Schema;
-import software.amazon.smithy.java.core.schema.SchemaUtils;
 import software.amazon.smithy.java.core.schema.SerializableStruct;
+import software.amazon.smithy.java.core.schema.ShapeUtils;
 
 /**
  * Replaces values of a top-level structure members with values for pagination.
@@ -35,7 +35,7 @@ final class PaginationInputSetter<I extends SerializableStruct> {
 
     I create(String token, Integer maxResults) {
         var builder = operation.inputBuilder();
-        SchemaUtils.copyShape(input, builder);
+        ShapeUtils.copyShape(input, builder);
         if (token != null) {
             builder.setMemberValue(inputTokenSchema, token);
         }

client/client-core/src/main/java/software/amazon/smithy/java/client/core/plugins/InjectIdempotencyTokenPlugin.java

@@ -11,8 +11,8 @@
 import software.amazon.smithy.java.client.core.interceptors.ClientInterceptor;
 import software.amazon.smithy.java.client.core.interceptors.InputHook;
 import software.amazon.smithy.java.context.Context;
-import software.amazon.smithy.java.core.schema.SchemaUtils;
 import software.amazon.smithy.java.core.schema.SerializableStruct;
+import software.amazon.smithy.java.core.schema.ShapeUtils;
 import software.amazon.smithy.java.logging.InternalLogger;
 import software.amazon.smithy.utils.SmithyInternalApi;
 
@@ -53,7 +53,7 @@ public <I extends SerializableStruct> I modifyBeforeSerialization(InputHook<I, ?
 
                 if (value == null) {
                     var builder = operation.inputBuilder();
-                    SchemaUtils.copyShape(hook.input(), builder);
+                    ShapeUtils.copyShape(hook.input(), builder);
                     var tokenProvider = hook.context().get(IDEMPOTENCY_TOKEN_PROVIDER);
                     var tokenValue = tokenProvider != null ? tokenProvider : UUID.randomUUID().toString();
                     builder.setMemberValue(tokenMember, tokenValue);

core/src/main/java/software/amazon/smithy/java/core/schema/SchemaUtils.java

@@ -5,50 +5,10 @@
 
 package software.amazon.smithy.java.core.schema;
 
-import java.util.function.Predicate;
-import software.amazon.smithy.java.core.serde.InterceptingSerializer;
-import software.amazon.smithy.java.core.serde.ShapeSerializer;
-
 public final class SchemaUtils {
 
     private SchemaUtils() {}
 
-    /**
-     * Create a serializable struct that only serializes members that pass the given predicate.
-     *
-     * @param schema Structure schema.
-     * @param struct Struct to serialize.
-     * @param memberPredicate Predicate that takes a member schema.
-     * @return the filtered struct.
-     */
-    public static SerializableStruct withFilteredMembers(
-            Schema schema,
-            SerializableStruct struct,
-            Predicate<Schema> memberPredicate
-    ) {
-        return new SerializableStruct() {
-            @Override
-            public Schema schema() {
-                return schema;
-            }
-
-            @Override
-            public void serializeMembers(ShapeSerializer serializer) {
-                struct.serializeMembers(new InterceptingSerializer() {
-                    @Override
-                    protected ShapeSerializer before(Schema schema) {
-                        return memberPredicate.test(schema) ? serializer : ShapeSerializer.nullSerializer();
-                    }
-                });
-            }
-
-            @Override
-            public <T> T getMemberValue(Schema member) {
-                return memberPredicate.test(schema()) ? struct.getMemberValue(member) : null;
-            }
-        };
-    }
-
     /**
      * Ensures that {@code member} is contained in {@code parent}, and if so returns {@code value}.
      *
@@ -91,19 +51,4 @@ public static <T> T validateSameMember(Schema expected, Schema actual, T value)
                         + ": " + actual.id());
     }
 
-    /**
-     * Attempts to copy the values from a struct into a shape builder.
-     *
-     * @param source The shape to copy from.
-     * @param sink   The builder to copy into.
-     * @throws IllegalArgumentException if the two shapes are incompatible and don't use the same schemas.
-     */
-    public static void copyShape(SerializableStruct source, ShapeBuilder<?> sink) {
-        for (var member : source.schema().members()) {
-            var value = source.getMemberValue(member);
-            if (value != null) {
-                sink.setMemberValue(member, value);
-            }
-        }
-    }
 }

core/src/main/java/software/amazon/smithy/java/core/schema/ShapeUtils.java

@@ -0,0 +1,219 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.java.core.schema;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.math.RoundingMode;
+import java.nio.ByteBuffer;
+import java.time.Instant;
+import java.util.HexFormat;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.function.Predicate;
+import java.util.stream.IntStream;
+import software.amazon.smithy.java.core.serde.InterceptingSerializer;
+import software.amazon.smithy.java.core.serde.ShapeDeserializer;
+import software.amazon.smithy.java.core.serde.ShapeSerializer;
+import software.amazon.smithy.java.core.serde.document.Document;
+import software.amazon.smithy.java.io.ByteBufferUtils;
+import software.amazon.smithy.model.shapes.ShapeType;
+
+public class ShapeUtils {
+
+    private ShapeUtils() {
+
+    }
+
+    /**
+     * Create a serializable struct that only serializes members that pass the given predicate.
+     *
+     * @param schema Structure schema.
+     * @param struct Struct to serialize.
+     * @param memberPredicate Predicate that takes a member schema.
+     * @return the filtered struct.
+     */
+    public static SerializableStruct withFilteredMembers(
+            Schema schema,
+            SerializableStruct struct,
+            Predicate<Schema> memberPredicate
+    ) {
+        return new SerializableStruct() {
+            @Override
+            public Schema schema() {
+                return schema;
+            }
+
+            @Override
+            public void serializeMembers(ShapeSerializer serializer) {
+                struct.serializeMembers(new InterceptingSerializer() {
+                    @Override
+                    protected ShapeSerializer before(Schema schema) {
+                        return memberPredicate.test(schema) ? serializer : ShapeSerializer.nullSerializer();
+                    }
+                });
+            }
+
+            @Override
+            public <T> T getMemberValue(Schema member) {
+                return memberPredicate.test(schema()) ? struct.getMemberValue(member) : null;
+            }
+        };
+    }
+
+    /**
+     * Attempts to copy the values from a struct into a shape builder.
+     *
+     * @param source The shape to copy from.
+     * @param sink   The builder to copy into.
+     * @throws IllegalArgumentException if the two shapes are incompatible and don't use the same schemas.
+     */
+    public static void copyShape(SerializableStruct source, ShapeBuilder<?> sink) {
+        for (var member : source.schema().members()) {
+            var value = source.getMemberValue(member);
+            if (value != null) {
+                sink.setMemberValue(member, value);
+            }
+        }
+    }
+
+    /**
+     * Generates a random instance of a shape using the provided builder.
+     *
+     * <p>This method populates the shape with randomly generated values for all its members.
+     * Required members are always populated, while optional members have a 50% chance of being set.
+     * For union types, exactly one member is randomly selected and populated.
+     *
+     * <p>This is useful for fuzz testing and generating test data.
+     *
+     * @param shapeBuilder The builder to use for constructing the shape.
+     * @param <T>          The type of shape to generate.
+     * @return A randomly generated instance of the shape.
+     */
+    public static <T extends SerializableShape> T generateRandom(ShapeBuilder<T> shapeBuilder) {
+        return shapeBuilder.deserialize(new RandomShapeGenerator()).build();
+    }
+
+    private static final class RandomShapeGenerator implements ShapeDeserializer {
+        @Override
+        public boolean readBoolean(Schema schema) {
+            return random().nextBoolean();
+        }
+
+        @Override
+        public ByteBuffer readBlob(Schema schema) {
+            var bytes = new byte[randomInt(100)];
+            random().nextBytes(bytes);
+            return ByteBuffer.wrap(bytes);
+        }
+
+        @Override
+        public byte readByte(Schema schema) {
+            return (byte) random().nextInt(Byte.MIN_VALUE, Byte.MAX_VALUE + 1);
+        }
+
+        @Override
+        public short readShort(Schema schema) {
+            return (short) random().nextInt(Short.MIN_VALUE, Short.MAX_VALUE + 1);
+        }
+
+        @Override
+        public int readInteger(Schema schema) {
+            return random().nextInt();
+        }
+
+        @Override
+        public long readLong(Schema schema) {
+            return random().nextLong();
+        }
+
+        @Override
+        public float readFloat(Schema schema) {
+            return random().nextFloat();
+        }
+
+        @Override
+        public double readDouble(Schema schema) {
+            return random().nextDouble();
+        }
+
+        @Override
+        public BigInteger readBigInteger(Schema schema) {
+            int times = randomInt(3);
+            var bigInt = BigInteger.valueOf(random().nextLong());
+            for (int i = 0; i < times; i++) {
+                bigInt = bigInt.multiply(BigInteger.valueOf(random().nextLong(Long.MAX_VALUE - 100, Long.MAX_VALUE)));
+            }
+            return bigInt;
+        }
+
+        @Override
+        public BigDecimal readBigDecimal(Schema schema) {
+            var bigDecimal = new BigDecimal(readBigInteger(schema));
+            int times = randomInt();
+            while (times-- > 0) {
+                bigDecimal = bigDecimal.divide(new BigDecimal(readBigInteger(schema)), RoundingMode.CEILING);
+            }
+            return bigDecimal;
+        }
+
+        @Override
+        public String readString(Schema schema) {
+            return HexFormat.of().formatHex(ByteBufferUtils.getBytes(readBlob(schema)));
+        }
+
+        @Override
+        public Document readDocument() {
+            //TODO add more shapes.
+            return Document.of(readString(null));
+        }
+
+        @Override
+        public Instant readTimestamp(Schema schema) {
+            return Instant.now();
+        }
+
+        @Override
+        public <T> void readStruct(Schema schema, T state, StructMemberConsumer<T> consumer) {
+            if (schema.type().isShapeType(ShapeType.UNION)) {
+                var member = schema.members().get(randomInt(schema.members().size()));
+                consumer.accept(state, member, this);
+            } else {
+                for (var member : schema.members()) {
+                    if (member.hasTrait(TraitKey.REQUIRED_TRAIT) || random().nextBoolean()) {
+                        consumer.accept(state, member, this);
+                    }
+                }
+            }
+        }
+
+        @Override
+        public <T> void readList(Schema schema, T state, ListMemberConsumer<T> consumer) {
+            IntStream.range(0, randomInt()).forEach(i -> consumer.accept(state, this));
+        }
+
+        @Override
+        public <T> void readStringMap(Schema schema, T state, MapMemberConsumer<String, T> consumer) {
+            IntStream.range(0, randomInt()).forEach(i -> consumer.accept(state, readString(schema), this));
+        }
+
+        @Override
+        public boolean isNull() {
+            return random().nextBoolean();
+        }
+
+        private static ThreadLocalRandom random() {
+            return ThreadLocalRandom.current();
+        }
+
+        private static int randomInt() {
+            return random().nextInt(10);
+        }
+
+        private static int randomInt(int bound) {
+            return random().nextInt(bound);
+        }
+    }
+}