Support _id aggregation operators for $group stage (#3096)

FerretDB · Jul 26, 2023 · 777222a · 777222a
1 parent 19e1cdb
commit 777222a
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Showing 5 changed files with 326 additions and 112 deletions.
diff --git a/integration/aggregate_documents_compat_test.go b/integration/aggregate_documents_compat_test.go
@@ -618,25 +618,35 @@ func TestAggregateCompatGroup(t *testing.T) {
 		},
 		"IDType": {
 			pipeline: bson.A{bson.D{{"$group", bson.D{
-				{"_id", bson.D{{"$type", "_id"}}},
+				{"_id", bson.D{{"$type", "$v"}}},
+				{"count", bson.D{{"$count", bson.D{}}}},
 			}}}},
-			skip: "https://github.com/FerretDB/FerretDB/issues/2679",
 		},
 		"IDSum": {
 			pipeline: bson.A{
 				bson.D{{"$sort", bson.D{{"_id", 1}}}},
 				bson.D{{"$group", bson.D{{"_id", bson.D{{"$sum", "$v"}}}}}},
 				bson.D{{"$sort", bson.D{{"_id", 1}}}},
 			},
-			skip: "https://github.com/FerretDB/FerretDB/issues/2694",
 		},
 		"IDSumNonExistentField": {
 			pipeline: bson.A{
 				bson.D{{"$sort", bson.D{{"_id", 1}}}},
 				bson.D{{"$group", bson.D{{"_id", bson.D{{"$sum", "$non-existent"}}}}}},
 				bson.D{{"$sort", bson.D{{"_id", 1}}}},
 			},
-			skip: "https://github.com/FerretDB/FerretDB/issues/2694",
+		},
+		"IDSumInvalid": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"_id", bson.D{{"$sum", "$"}}}}}},
+			},
+			resultType: emptyResult,
+		},
+		"IDSumRecursiveInvalid": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"_id", bson.D{{"$sum", bson.D{{"$sum", "$"}}}}}}}},
+			},
+			resultType: emptyResult,
 		},
 	}
 

diff --git a/integration/aggregate_documents_test.go b/integration/aggregate_documents_test.go
@@ -94,7 +94,7 @@ func TestAggregateGroupErrors(t *testing.T) {
 		altMessage string              // optional, alternative error message for FerretDB, ignored if empty
 		skip       string              // optional, skip test with a specified reason
 	}{
-		"StageGroupUnaryOperatorSum": {
+		"UnaryOperatorSum": {
 			pipeline: bson.A{
 				bson.D{{"$group", bson.D{{"sum", bson.D{{"$sum", bson.A{}}}}}}},
 			},
@@ -105,6 +105,93 @@ func TestAggregateGroupErrors(t *testing.T) {
 			},
 			altMessage: "The $sum accumulator is a unary operator",
 		},
+		"TypeEmpty": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"v", bson.D{}}}}},
+			},
+			err: &mongo.CommandError{
+				Code:    40234,
+				Name:    "Location40234",
+				Message: "The field 'v' must be an accumulator object",
+			},
+		},
+		"TwoOperators": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"_id", bson.D{{"$type", int32(42)}, {"$op", int32(42)}}}}}},
+			},
+			err: &mongo.CommandError{
+				Code:    15983,
+				Name:    "Location15983",
+				Message: "An object representing an expression must have exactly one field: { $type: 42, $op: 42 }",
+			},
+			altMessage: "An object representing an expression must have exactly one field",
+		},
+		"TypeInvalidLen": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"_id", bson.D{{"$type", bson.A{"foo", "bar"}}}}}}},
+			},
+			err: &mongo.CommandError{
+				Code:    16020,
+				Name:    "Location16020",
+				Message: "Expression $type takes exactly 1 arguments. 2 were passed in.",
+			},
+		},
+		"NonExistentOperator": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"_id", bson.D{{"$non-existent", "foo"}}}}}},
+			},
+			err: &mongo.CommandError{
+				Code:    168,
+				Name:    "InvalidPipelineOperator",
+				Message: "Unrecognized expression '$non-existent'",
+			},
+		},
+		"SumEmptyExpression": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{
+					{"_id", bson.D{{"$sum", "$"}}},
+				}}},
+			},
+			err: &mongo.CommandError{
+				Code:    16872,
+				Name:    "Location16872",
+				Message: "'$' by itself is not a valid FieldPath",
+			},
+		},
+		"SumEmptyVariable": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{
+					{"_id", bson.D{{"$sum", "$$"}}},
+				}}},
+			},
+			err: &mongo.CommandError{
+				Code:    9,
+				Name:    "FailedToParse",
+				Message: "empty variable names are not allowed",
+			},
+		},
+		"SumDollarVariable": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{
+					{"_id", bson.D{{"$sum", "$$$"}}},
+				}}},
+			},
+			err: &mongo.CommandError{
+				Code:    9,
+				Name:    "FailedToParse",
+				Message: "'$' starts with an invalid character for a user variable name",
+			},
+		},
+		"RecursiveNonExistentOperator": {
+			pipeline: bson.A{
+				bson.D{{"$group", bson.D{{"_id", bson.D{{"$type", bson.D{{"$non-existent", "foo"}}}}}}}},
+			},
+			err: &mongo.CommandError{
+				Code:    168,
+				Name:    "InvalidPipelineOperator",
+				Message: "Unrecognized expression '$non-existent'",
+			},
+		},
 	} {
 		name, tc := name, tc
 		t.Run(name, func(t *testing.T) {