Allow optimized FILTER_AS_MATCH strategy to be used with simple filtering.

resolves #163

Author: Andy2003

core/src/main/kotlin/org/neo4j/graphql/handler/QueryHandler.kt

@@ -86,7 +86,7 @@ class QueryHandler private constructor(
 
         val ongoingReading = if ((env.getContext() as? QueryContext)?.optimizedQuery?.contains(QueryContext.OptimizationStrategy.FILTER_AS_MATCH) == true) {
 
-            OptimizedFilterHandler(type).generateFilterQuery(variable, field, match, propertyContainer)
+            OptimizedFilterHandler(type).generateFilterQuery(variable, fieldDefinition, field, match, propertyContainer)
 
         } else {
 

core/src/main/kotlin/org/neo4j/graphql/handler/filter/OptimizedFilterHandler.kt

@@ -4,13 +4,15 @@ import graphql.language.Field
 import graphql.language.NullValue
 import graphql.language.ObjectValue
 import graphql.language.Value
+import graphql.schema.GraphQLFieldDefinition
 import graphql.schema.GraphQLFieldsContainer
 import org.neo4j.cypherdsl.core.*
 import org.neo4j.cypherdsl.core.Cypher
 import org.neo4j.cypherdsl.core.StatementBuilder.*
 import org.neo4j.graphql.*
 import org.neo4j.graphql.handler.projection.ProjectionBase
 import org.neo4j.graphql.parser.ParsedQuery
+import org.neo4j.graphql.parser.QueryParser
 import org.neo4j.graphql.parser.QueryParser.parseFilter
 import org.neo4j.graphql.parser.RelationPredicate
 
@@ -24,22 +26,30 @@ typealias ConditionBuilder = (ExposesWith) -> OrderableOngoingReadingAndWithWith
 
 class OptimizedFilterHandler(val type: GraphQLFieldsContainer) : ProjectionBase() {
 
-    fun generateFilterQuery(variable: String, field: Field, readingWithoutWhere: OngoingReadingWithoutWhere, rootNode: PropertyContainer): OngoingReading {
+    fun generateFilterQuery(variable: String, fieldDefinition: GraphQLFieldDefinition, field: Field, readingWithoutWhere: OngoingReadingWithoutWhere, rootNode: PropertyContainer): OngoingReading {
         if (type.isRelationType()) {
             throw OptimizedQueryException("Optimization for relationship entity type is not implemented. Please provide a test case to help adding further cases.")
         }
 
-        var withWithoutWhere: OngoingReading? = null
+        var ongoingReading: OngoingReading? = null
 
+        val filteredArguments = field.arguments.filterNot { setOf(FIRST, OFFSET, ORDER_BY, FILTER).contains(it.name) }
+        if (filteredArguments.isNotEmpty()) {
+            val parsedQuery = QueryParser.parseArguments(filteredArguments, fieldDefinition, type)
+            val condition = handleQuery(variable, "", rootNode, parsedQuery, type)
+            ongoingReading = readingWithoutWhere.where(condition)
+        }
         for (argument in field.arguments) {
             if (argument.name == FILTER) {
                 val parsedQuery = parseFilter(argument.value as ObjectValue, type)
-                withWithoutWhere = NestingLevelHandler(parsedQuery, false, rootNode, variable, readingWithoutWhere,
+                ongoingReading = NestingLevelHandler(parsedQuery, false, rootNode, variable, ongoingReading
+                        ?: readingWithoutWhere,
                         type, argument.value, linkedSetOf(rootNode.requiredSymbolicName))
                     .parseFilter()
             }
         }
-        return withWithoutWhere ?: readingWithoutWhere
+
+        return ongoingReading ?: readingWithoutWhere
     }
 
     /**

core/src/main/kotlin/org/neo4j/graphql/handler/projection/ProjectionBase.kt

@@ -88,7 +88,7 @@ open class ProjectionBase {
                 ?: result
     }
 
-    private fun handleQuery(
+    protected fun handleQuery(
             variablePrefix: String,
             variableSuffix: String,
             propertyContainer: PropertyContainer,

core/src/test/resources/issues/gh-163.adoc

@@ -7,11 +7,17 @@
 [source,graphql,schema=true]
 ----
 type Person {
-    name: String
+  name: String
+  born: Int
+  actedIn: [Movie!]! @relation(name: "ACTED_IN", direction:OUT)
+}
+
+type Movie {
+  title: String!
 }
 ----
 
-== Issue
+== Query without filter
 
 .Query configuration
 [source,json,query-config=true]
@@ -40,5 +46,52 @@ query {
 .Cypher
 [source,cypher]
 ----
-MATCH (person: `Person`) where person.name = $personName RETURN person { .name } AS person
+MATCH (person:Person)
+WHERE person.name = $personName
+RETURN person {
+	.name
+} AS person
+----
+
+== Query with simple conditions and filter
+
+.Query configuration
+[source,json,query-config=true]
+----
+{  "optimizedQuery":  ["FILTER_AS_MATCH"] }
+----
+
+.GraphQL-Query
+[source,graphql]
+----
+query {
+  person(name:"test", filter: { born_gt: 1970, actedIn_none: { title: "Unforgiven" }}) {
+    name
+  }
+}
+----
+
+.Cypher Params
+[source,json]
+----
+{
+  "personActedInNoneTitle" : "Unforgiven",
+  "personBornGt" : 1970
+}
+----
+
+.Cypher
+[source,cypher]
+----
+MATCH (person:Person)
+WHERE person.born > $personBornGt
+WITH person
+OPTIONAL MATCH (person)-[:ACTED_IN]->(personActedInNone:Movie)
+WHERE personActedInNone.title = $personActedInNoneTitle
+WITH person, count(DISTINCT personActedInNone) AS personActedInNoneCount
+WHERE personActedInNoneCount = 0
+WITH DISTINCT person
+RETURN person {
+	.name
+} AS person
 ----