From d190439f1a9ecf392f962cd3cd5e56e2a7c54993 Mon Sep 17 00:00:00 2001
From: Antonio Lucas Neres de Oliveira Barros <antoniolucasnobar@gmail.com>
Date: Fri, 13 Sep 2019 11:32:19 -0300
Subject: [PATCH] [#4] throw exception when client asks for wrong columns:

- to ensure consistent behavior, the server should not respond when the
client asks wrong columns
---
 .../breezil/queryfier/engine/QueryBuilder.java | 18 +++++++++++-------
 .../queryfier/engine/QueryBuilderTest.java     |  8 ++++++++
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/main/java/io/breezil/queryfier/engine/QueryBuilder.java b/src/main/java/io/breezil/queryfier/engine/QueryBuilder.java
index 7f0b613..9cc42bd 100644
--- a/src/main/java/io/breezil/queryfier/engine/QueryBuilder.java
+++ b/src/main/java/io/breezil/queryfier/engine/QueryBuilder.java
@@ -28,6 +28,13 @@ public class QueryBuilder {
 	public QueryBuilder() {
 		this.joinMaps = new HashMap<>();
 	}
+    
+    private void validateColumns(QBase<? extends Object, ? extends Object> toParse, QQuery q) {
+        if (toParse.getColumns().size() != q.getProjections().size()) {
+            throw new IllegalArgumentException(
+                    "Some column(s): " + toParse.getColumns() + " do not belong to the entity you requested.");
+        }
+    }
 
 	@SuppressWarnings("rawtypes")
 	public QQuery parseQuery(QBase<? extends Object, ? extends Object> toParse) throws IllegalAccessException {
@@ -203,25 +210,22 @@ public List<QSort> mapToActualColumns(List<String> sortedColumns) {
 
 	private void configureProjections(QBase<? extends Object, ? extends Object> toParse, QQuery q, List<QProjection> projections) {
 		if (toParse.getColumns().isEmpty()) {
-			projections.forEach(p -> q.addProjection(p));
+			projections.forEach(q::addProjection);
 		} else {
 			addColumnsWithProjections(toParse, q, projections);
 			addColumnsWithAggregationFunctions(toParse, q);
+            validateColumns(toParse, q);
 		}
 	}
 
 	private void addColumnsWithAggregationFunctions(QBase<? extends Object, ? extends Object> toParse, QQuery q) {
 		toParse.getColumns().stream()
 			.filter(col -> col.contains(QProjection.SPLITTER))
-			.forEach(col -> {
-				q.addProjection(new QProjection(col)); 
-		});
+                .forEach(col -> q.addProjection(new QProjection(col)));
 	}
 
 	private void addColumnsWithProjections(QBase<? extends Object, ? extends Object> toParse, QQuery q, List<QProjection> projections) {
-		projections.stream().filter(p -> {
-			return toParse.getColumns().contains(p.getAlias());
-		}).forEach(p -> q.addProjection(p));
+        projections.stream().filter(p -> toParse.getColumns().contains(p.getAlias())).forEach(q::addProjection);
 	}
 
 	private void configureSelectionAndParameter(QBase<? extends Object, ? extends Object> toParse, QQuery q, Field f) throws IllegalAccessException {
diff --git a/src/test/java/io/breezil/queryfier/engine/QueryBuilderTest.java b/src/test/java/io/breezil/queryfier/engine/QueryBuilderTest.java
index 2933a32..d9ff926 100644
--- a/src/test/java/io/breezil/queryfier/engine/QueryBuilderTest.java
+++ b/src/test/java/io/breezil/queryfier/engine/QueryBuilderTest.java
@@ -53,6 +53,14 @@ public void recuperaApenasColunasInformadas() {
 				NUMBER_OF_QUERIED_PROJECTIONS, q.getProjections().size());
 	}
 	
+	@Test(expected = IllegalArgumentException.class)
+    public void shoudFailWithWrongColumns() {
+        sf.addColumn("main");        
+        sf.addColumn("president");
+        QQuery q = convertDTO2Query(sf);
+        Assert.fail("president does not belong to StateFilter. It should fail then");
+    }
+	
 	@Test
 	public void deveOrdenarAscendentemente() {
 		sf.addSortedColumns("governor");