Issue 47: Query expression planner now recognises GSIs (#48)

The query expression planner now recognises GSIs, and will use them if the expression can be executed as a query over an index.

test/testdynamo/client.go

@@ -15,6 +15,7 @@ import (
 
 type TestData struct {
 	TableName string
+	Index     []string
 	Data      []map[string]interface{}
 }
 
@@ -31,7 +32,7 @@ func SetupTestTable(t *testing.T, testData []TestData) *dynamodb.Client {
 		dynamodb.WithEndpointResolver(dynamodb.EndpointResolverFromURL("http://localhost:4566")))
 
 	for _, table := range testData {
-		_, err = dynamoClient.CreateTable(ctx, &dynamodb.CreateTableInput{
+		tableInput := &dynamodb.CreateTableInput{
 			TableName: aws.String(table.TableName),
 			KeySchema: []types.KeySchemaElement{
 				{AttributeName: aws.String("pk"), KeyType: types.KeyTypeHash},
@@ -45,7 +46,28 @@ func SetupTestTable(t *testing.T, testData []TestData) *dynamodb.Client {
 				ReadCapacityUnits:  aws.Int64(100),
 				WriteCapacityUnits: aws.Int64(100),
 			},
-		})
+		}
+		for _, index := range table.Index {
+			tableInput.AttributeDefinitions = append(tableInput.AttributeDefinitions, types.AttributeDefinition{
+				AttributeName: aws.String(index),
+				AttributeType: types.ScalarAttributeTypeS,
+			})
+			tableInput.GlobalSecondaryIndexes = append(tableInput.GlobalSecondaryIndexes, types.GlobalSecondaryIndex{
+				IndexName: aws.String(index + "-index"),
+				KeySchema: []types.KeySchemaElement{
+					{AttributeName: aws.String(index), KeyType: types.KeyTypeHash},
+				},
+				Projection: &types.Projection{
+					ProjectionType: types.ProjectionTypeAll,
+				},
+				ProvisionedThroughput: &types.ProvisionedThroughput{
+					ReadCapacityUnits:  aws.Int64(100),
+					WriteCapacityUnits: aws.Int64(100),
+				},
+			})
+		}
+
+		_, err = dynamoClient.CreateTable(ctx, tableInput)
 		assert.NoError(t, err)
 
 		for _, item := range table.Data {