internal/rule: fix projections when squash joins

Signed-off-by: Manuel Carmona <[email protected]>

Author: mcarmonaa

integration_test.go

@@ -183,6 +183,52 @@ func TestIntegration(t *testing.T) {
 				{int32(3), "worktree", "[email protected]"},
 			},
 		},
+		{
+			`SELECT
+				c.commit_hash AS hash,
+				c.commit_message AS message,
+				commit_author_name AS author,
+				te.tree_entry_name AS file
+			FROM
+				commits c
+			NATURAL JOIN commit_trees
+			NATURAL JOIN tree_entries as te
+			WHERE te.repository_id='worktree'
+			LIMIT 8`,
+			[]sql.Row{
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", ".gitignore"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "CHANGELOG"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "LICENSE"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "README"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "binary.jpg"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "go"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "json"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "Máximo Cuadros Ortiz", "php"},
+			},
+		},
+		{
+			`SELECT
+				c.commit_hash AS hash,
+				c.commit_message AS message,
+				te.tree_entry_name AS file,
+				te.tree_hash AS thash
+			FROM
+				commits c
+			NATURAL JOIN commit_trees
+			NATURAL JOIN tree_entries as te
+			WHERE te.repository_id='worktree'
+			LIMIT 8`,
+			[]sql.Row{
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", ".gitignore", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "CHANGELOG", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "LICENSE", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "README", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "binary.jpg", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "go", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "json", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+				{"e8d3ffab552895c19b9fcf7aa264d277cde33881", "some code in a branch\n", "php", "dbd3641b371024f44d0e469a9c8f5457b0660de1"},
+			},
+		},
 	}
 
 	runTests := func(t *testing.T) {

internal/rule/squashjoins.go

@@ -108,34 +108,16 @@ func countProjectSquashes(n sql.Node) int {
 }
 
 func squashProjects(parent, child *plan.Project) (sql.Node, bool) {
-	var projections []sql.Expression
-	for _, expr := range parent.Expressions() {
-		parentField, ok := expr.(*expression.GetField)
-		if !ok {
-			return nil, false
-		}
-
-		index := parentField.Index()
-		for _, e := range child.Expressions() {
-			childField, ok := e.(*expression.GetField)
-			if !ok {
-				return nil, false
-			}
+	projections := make([]sql.Expression, len(parent.Expressions()))
+	schema := child.Child.Schema()
 
-			if referenceSameColumn(parentField, childField) {
-				index = childField.Index()
-			}
+	for i, e := range parent.Expressions() {
+		fe, err := fixFieldIndexes(e, schema)
+		if err != nil {
+			return nil, false
 		}
 
-		projection := expression.NewGetFieldWithTable(
-			index,
-			parentField.Type(),
-			parentField.Table(),
-			parentField.Name(),
-			parentField.IsNullable(),
-		)
-
-		projections = append(projections, projection)
+		projections[i] = fe
 	}
 
 	return plan.NewProject(projections, child.Child), true