Fix #158: support empty Projection clause, validate non-empty

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/Projectable.java

@@ -0,0 +1,15 @@
+package io.stargate.sgv2.jsonapi.api.model.command;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import io.stargate.sgv2.jsonapi.service.projection.DocumentProjector;
+
+/*
+ * All the commands that need Projection definitions will have to implement this.
+ */
+public interface Projectable {
+  JsonNode projectionDefinition();
+
+  default DocumentProjector buildProjector() {
+    return DocumentProjector.createFromDefinition(projectionDefinition());
+  }
+}

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/impl/FindCommand.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.databind.JsonNode;
 import io.stargate.sgv2.jsonapi.api.model.command.Filterable;
 import io.stargate.sgv2.jsonapi.api.model.command.ReadCommand;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.FilterClause;
@@ -15,6 +16,7 @@
 @JsonTypeName("find")
 public record FindCommand(
     @Valid @JsonProperty("filter") FilterClause filterClause,
+    @JsonProperty("projection") JsonNode projectionDefinition,
     @Valid @JsonProperty("sort") SortClause sortClause,
     @Valid @Nullable Options options)
     implements ReadCommand, Filterable {

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/impl/FindOneAndUpdateCommand.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.databind.JsonNode;
 import io.stargate.sgv2.jsonapi.api.model.command.Filterable;
 import io.stargate.sgv2.jsonapi.api.model.command.ReadCommand;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.FilterClause;
@@ -18,6 +19,7 @@
 @JsonTypeName("findOneAndUpdate")
 public record FindOneAndUpdateCommand(
     @Valid @JsonProperty("filter") FilterClause filterClause,
+    @JsonProperty("projection") JsonNode projectionDefinition,
     @NotNull @Valid @JsonProperty("update") UpdateClause updateClause,
     @Valid @Nullable Options options)
     implements ReadCommand, Filterable {

src/main/java/io/stargate/sgv2/jsonapi/api/model/command/impl/FindOneCommand.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
+import com.fasterxml.jackson.databind.JsonNode;
 import io.stargate.sgv2.jsonapi.api.model.command.Filterable;
 import io.stargate.sgv2.jsonapi.api.model.command.ReadCommand;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.FilterClause;
@@ -13,5 +14,6 @@
 @JsonTypeName("findOne")
 public record FindOneCommand(
     @Valid @JsonProperty("filter") FilterClause filterClause,
+    @JsonProperty("projection") JsonNode projectionDefinition,
     @Valid @JsonProperty("sort") SortClause sortClause)
     implements ReadCommand, Filterable {}

src/main/java/io/stargate/sgv2/jsonapi/exception/ErrorCode.java

@@ -34,6 +34,8 @@ public enum ErrorCode {
 
   UNSUPPORTED_OPERATION("Unsupported operation class"),
 
+  UNSUPPORTED_PROJECTION_PARAM("Unsupported projection parameter"),
+
   UNSUPPORTED_UPDATE_DATA_TYPE("Unsupported update data type"),
 
   UNSUPPORTED_UPDATE_OPERATION("Unsupported update operation"),

src/main/java/io/stargate/sgv2/jsonapi/service/operation/model/impl/FindOperation.java

@@ -15,9 +15,11 @@
 import io.stargate.sgv2.jsonapi.service.bridge.executor.QueryExecutor;
 import io.stargate.sgv2.jsonapi.service.operation.model.ReadOperation;
 import io.stargate.sgv2.jsonapi.service.operation.model.ReadType;
+import io.stargate.sgv2.jsonapi.service.projection.DocumentProjector;
 import io.stargate.sgv2.jsonapi.service.shredding.model.DocumentId;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import java.util.function.Supplier;
 
 /** Operation that returns the documents or its key based on the filter condition. */
@@ -28,6 +30,7 @@ public record FindOperation(
     int limit,
     int pageSize,
     ReadType readType,
+    Optional<DocumentProjector> projector,
     ObjectMapper objectMapper)
     implements ReadOperation {
 

src/main/java/io/stargate/sgv2/jsonapi/service/projection/DocumentProjector.java

@@ -0,0 +1,34 @@
+package io.stargate.sgv2.jsonapi.service.projection;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import io.stargate.sgv2.jsonapi.exception.ErrorCode;
+import io.stargate.sgv2.jsonapi.exception.JsonApiException;
+
+/**
+ * Helper class that implements functionality needed to support projections on documents fetched via
+ * various {@code find} commands.
+ */
+public class DocumentProjector {
+  private DocumentProjector() {}
+
+  public static DocumentProjector createFromDefinition(JsonNode projectionDefinition) {
+    if (projectionDefinition == null) {
+      return null;
+    }
+    if (!projectionDefinition.isObject()) {
+      throw new JsonApiException(
+          ErrorCode.UNSUPPORTED_PROJECTION_PARAM,
+          ErrorCode.UNSUPPORTED_PROJECTION_PARAM.getMessage()
+              + ": definition must be OBJECT, was "
+              + projectionDefinition.getNodeType());
+    }
+    if (projectionDefinition.isEmpty()) {
+      return null;
+    }
+    return new DocumentProjector();
+  }
+
+  public void applyProjection(JsonNode document) {
+    ; // To implement
+  }
+}

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/DeleteManyCommandResolver.java

@@ -12,6 +12,7 @@
 import io.stargate.sgv2.jsonapi.service.resolver.model.CommandResolver;
 import io.stargate.sgv2.jsonapi.service.resolver.model.impl.matcher.FilterableResolver;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -58,6 +59,7 @@ private FindOperation getFindOperation(CommandContext commandContext, DeleteMany
         documentConfig.maxDocumentDeleteCount() + 1,
         documentConfig.defaultPageSize(),
         ReadType.KEY,
+        Optional.empty(),
         objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/DeleteOneCommandResolver.java

@@ -12,6 +12,7 @@
 import io.stargate.sgv2.jsonapi.service.resolver.model.CommandResolver;
 import io.stargate.sgv2.jsonapi.service.resolver.model.impl.matcher.FilterableResolver;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -46,6 +47,7 @@ public Class<DeleteOneCommand> getCommandClass() {
 
   private FindOperation getFindOperation(CommandContext commandContext, DeleteOneCommand command) {
     List<DBFilterBase> filters = resolve(commandContext, command);
-    return new FindOperation(commandContext, filters, null, 1, 1, ReadType.KEY, objectMapper);
+    return new FindOperation(
+        commandContext, filters, null, 1, 1, ReadType.KEY, Optional.empty(), objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/FindCommandResolver.java

@@ -12,6 +12,7 @@
 import io.stargate.sgv2.jsonapi.service.resolver.model.CommandResolver;
 import io.stargate.sgv2.jsonapi.service.resolver.model.impl.matcher.FilterableResolver;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -45,6 +46,13 @@ public Operation resolveCommand(CommandContext commandContext, FindCommand comma
     int pageSize = documentConfig.defaultPageSize();
     String pagingState = command.options() != null ? command.options().pagingState() : null;
     return new FindOperation(
-        commandContext, filters, pagingState, limit, pageSize, ReadType.DOCUMENT, objectMapper);
+        commandContext,
+        filters,
+        pagingState,
+        limit,
+        pageSize,
+        ReadType.DOCUMENT,
+        Optional.empty(),
+        objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/FindOneAndUpdateCommandResolver.java

@@ -14,6 +14,7 @@
 import io.stargate.sgv2.jsonapi.service.shredding.Shredder;
 import io.stargate.sgv2.jsonapi.service.updater.DocumentUpdater;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -67,6 +68,7 @@ public Operation resolveCommand(CommandContext commandContext, FindOneAndUpdateC
   private FindOperation getFindOperation(
       CommandContext commandContext, FindOneAndUpdateCommand command) {
     List<DBFilterBase> filters = resolve(commandContext, command);
-    return new FindOperation(commandContext, filters, null, 1, 1, ReadType.DOCUMENT, objectMapper);
+    return new FindOperation(
+        commandContext, filters, null, 1, 1, ReadType.DOCUMENT, Optional.empty(), objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/FindOneCommandResolver.java

@@ -10,6 +10,7 @@
 import io.stargate.sgv2.jsonapi.service.resolver.model.CommandResolver;
 import io.stargate.sgv2.jsonapi.service.resolver.model.impl.matcher.FilterableResolver;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -34,6 +35,7 @@ public Class<FindOneCommand> getCommandClass() {
   public Operation resolveCommand(CommandContext commandContext, FindOneCommand command) {
 
     List<DBFilterBase> filters = resolve(commandContext, command);
-    return new FindOperation(commandContext, filters, null, 1, 1, ReadType.DOCUMENT, objectMapper);
+    return new FindOperation(
+        commandContext, filters, null, 1, 1, ReadType.DOCUMENT, Optional.empty(), objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/UpdateManyCommandResolver.java

@@ -14,6 +14,7 @@
 import io.stargate.sgv2.jsonapi.service.shredding.Shredder;
 import io.stargate.sgv2.jsonapi.service.updater.DocumentUpdater;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -71,6 +72,7 @@ private FindOperation getFindOperation(CommandContext commandContext, UpdateMany
         documentConfig.maxDocumentUpdateCount() + 1,
         documentConfig.defaultPageSize(),
         ReadType.DOCUMENT,
+        Optional.empty(),
         objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/UpdateOneCommandResolver.java

@@ -14,6 +14,7 @@
 import io.stargate.sgv2.jsonapi.service.shredding.Shredder;
 import io.stargate.sgv2.jsonapi.service.updater.DocumentUpdater;
 import java.util.List;
+import java.util.Optional;
 import javax.enterprise.context.ApplicationScoped;
 import javax.inject.Inject;
 
@@ -64,6 +65,7 @@ public Operation resolveCommand(CommandContext commandContext, UpdateOneCommand
 
   private FindOperation getFindOperation(CommandContext commandContext, UpdateOneCommand command) {
     List<DBFilterBase> filters = resolve(commandContext, command);
-    return new FindOperation(commandContext, filters, null, 1, 1, ReadType.DOCUMENT, objectMapper);
+    return new FindOperation(
+        commandContext, filters, null, 1, 1, ReadType.DOCUMENT, Optional.empty(), objectMapper);
   }
 }

src/main/java/io/stargate/sgv2/jsonapi/service/resolver/model/impl/matcher/FilterableResolver.java

@@ -3,20 +3,23 @@
 import io.stargate.sgv2.jsonapi.api.model.command.Command;
 import io.stargate.sgv2.jsonapi.api.model.command.CommandContext;
 import io.stargate.sgv2.jsonapi.api.model.command.Filterable;
+import io.stargate.sgv2.jsonapi.api.model.command.Projectable;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.ArrayComparisonOperator;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.ElementComparisonOperator;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.JsonType;
 import io.stargate.sgv2.jsonapi.api.model.command.clause.filter.ValueComparisonOperator;
 import io.stargate.sgv2.jsonapi.exception.ErrorCode;
 import io.stargate.sgv2.jsonapi.exception.JsonApiException;
 import io.stargate.sgv2.jsonapi.service.operation.model.impl.DBFilterBase;
+import io.stargate.sgv2.jsonapi.service.projection.DocumentProjector;
 import io.stargate.sgv2.jsonapi.service.shredding.model.DocValueHasher;
 import io.stargate.sgv2.jsonapi.service.shredding.model.DocumentId;
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import javax.inject.Inject;
 
 /**
@@ -83,6 +86,13 @@ protected List<DBFilterBase> resolve(CommandContext commandContext, T command) {
     return matchRules.apply(commandContext, command);
   }
 
+  protected Optional<DocumentProjector> getProjector(T command) {
+    if (command instanceof Projectable) {
+      return Optional.ofNullable(((Projectable) command).buildProjector());
+    }
+    return Optional.empty();
+  }
+
   private List<DBFilterBase> findById(CommandContext commandContext, CaptureGroups<T> captures) {
     List<DBFilterBase> filters = new ArrayList<>();
     final CaptureGroup<DocumentId> idGroup =

src/test/java/io/stargate/sgv2/jsonapi/service/operation/model/impl/DeleteOperationTest.java

@@ -21,6 +21,7 @@
 import io.stargate.sgv2.jsonapi.service.shredding.model.DocValueHasher;
 import io.stargate.sgv2.jsonapi.service.shredding.model.DocumentId;
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 import java.util.function.Supplier;
 import javax.inject.Inject;
@@ -94,6 +95,7 @@ public void deleteWithId() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 3);
       Supplier<CommandResult> execute =
@@ -146,6 +148,7 @@ public void deleteWithIdNoData() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
 
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 3);
@@ -215,6 +218,7 @@ public void deleteWithDynamic() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 3);
 
@@ -321,6 +325,7 @@ public void deleteWithDynamicRetry() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 2);
 
@@ -429,6 +434,7 @@ public void deleteWithDynamicRetryFailure() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 2);
 
@@ -532,6 +538,7 @@ public void deleteWithDynamicRetryConcurrentDelete() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 2);
 
@@ -617,6 +624,7 @@ public void deleteManyWithDynamic() {
               3,
               2,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 2, 3);
 
@@ -700,6 +708,7 @@ public void deleteManyWithDynamicPaging() {
               3,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 2, 3);
 
@@ -789,6 +798,7 @@ public void deleteManyWithDynamicPagingAndMoreData() {
               3,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 2, 3);
 
@@ -849,6 +859,7 @@ public void deleteWithNoResult() {
               1,
               1,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 1, 3);
 
@@ -969,6 +980,7 @@ public void errorPartial() {
               3,
               3,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 2, 3);
 
@@ -1139,6 +1151,7 @@ public void errorAll() {
               3,
               3,
               ReadType.KEY,
+              Optional.empty(),
               objectMapper);
       DeleteOperation operation = new DeleteOperation(COMMAND_CONTEXT, findOperation, 2, 3);