#69 Fix the sum and avg function for the only numeric value. (#70)

Author: spyzhov

README.md

@@ -53,7 +53,7 @@ func main() {
 You can download `ajson` cli from the [release page](https://github.com/spyzhov/ajson/releases), or install from the source:
 
 ```shell script
-go get github.com/spyzhov/ajson/cmd/[email protected].2
+go get github.com/spyzhov/ajson/cmd/[email protected].3
 ```
 
 Usage:

cmd/ajson/main.go

@@ -13,7 +13,7 @@ import (
 	"github.com/spyzhov/ajson"
 )
 
-var version = "v0.9.2"
+var version = "v0.9.3"
 
 func usage() {
 	text := ``

jsonpath_test.go

@@ -1595,3 +1595,72 @@ func TestEval_issue_67(t *testing.T) {
 		})
 	}
 }
+
+// TestEval_issue_69 is a test for https://github.com/spyzhov/ajson/issues/69
+func TestEval_issue_69(t *testing.T) {
+	root := Must(Unmarshal([]byte(`
+{
+  "items": [
+    {
+      "price":1, 
+      "type": "A"
+    }, 
+    {
+      "price":2, 
+      "type": "B"
+    }, 
+    {
+      "price":3, 
+      "type": "C"
+    },
+	null
+  ]
+}`)))
+
+	tests := []struct {
+		name       string
+		wantResult interface{}
+	}{
+		{
+			name:       `sum($.items[?(@.type == "A")].price)`,
+			wantResult: float64(1),
+		},
+		{
+			name:       `avg($.items[?(@.type == "A")].price)`,
+			wantResult: float64(1),
+		},
+		{
+			name:       `sum($.items[?(@.type == "D")].price)`,
+			wantResult: nil,
+		},
+		{
+			name:       `avg($.items[?(@.type == "D")].price)`,
+			wantResult: nil,
+		},
+		{
+			name:       `sum($.items[?(@ == null)].price)`,
+			wantResult: nil,
+		},
+		{
+			name:       `avg($.items[?(@ == null)].price)`,
+			wantResult: nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotResult, err := Eval(root, tt.name)
+			if err != nil {
+				t.Errorf("Eval(avg|sum) error = %v", err)
+				return
+			}
+			value, err := gotResult.Value()
+			if err != nil {
+				t.Errorf("Node.Value() error = %v", err)
+				return
+			}
+			if !reflect.DeepEqual(value, tt.wantResult) {
+				t.Errorf("Eval(avg|sum) gotResult = %v, want %v", gotResult, tt.wantResult)
+			}
+		})
+	}
+}

math.go

@@ -407,6 +407,13 @@ var (
 				}
 				return valueNode(nil, "avg", Numeric, sum/float64(node.Size())), nil
 			}
+			if node.IsNumeric() {
+				value, err := node.GetNumeric()
+				if err != nil {
+					return nil, err
+				}
+				return valueNode(nil, "avg", Numeric, value), nil
+			}
 			return valueNode(nil, "avg", Null, nil), nil
 		},
 		"b64decode": func(node *Node) (result *Node, err error) {
@@ -481,6 +488,13 @@ var (
 				}
 				return valueNode(nil, "sum", Numeric, sum), nil
 			}
+			if node.IsNumeric() {
+				value, err := node.GetNumeric()
+				if err != nil {
+					return nil, err
+				}
+				return valueNode(nil, "sum", Numeric, value), nil
+			}
 			return valueNode(nil, "sum", Null, nil), nil
 		},
 		"not": func(node *Node) (result *Node, err error) {

math_test.go

@@ -456,7 +456,7 @@ func TestFunctions2(t *testing.T) {
 			valueNode(nil, "", Numeric, "foo"),
 			valueNode(nil, "", Numeric, "foo"),
 		}), fail: true},
-		{name: "avg error 2", fname: "avg", value: _e, fail: false, result: NullNode("")},
+		{name: "avg error 2", fname: "avg", value: _e, fail: true},
 		{name: "avg array 1", fname: "avg", value: ArrayNode("test", []*Node{
 			NumericNode("", 1),
 			NumericNode("", 1),
@@ -475,6 +475,7 @@ func TestFunctions2(t *testing.T) {
 		}), result: NumericNode("", 2)},
 		{name: "avg array blank", fname: "avg", value: ArrayNode("test", []*Node{}), result: NumericNode("", 0)},
 		{name: "avg nil", fname: "avg", value: nil, result: NullNode("")},
+		{name: "avg one", fname: "avg", value: NumericNode("", 123), result: NumericNode("", 123)},
 
 		{name: "b64encode_std_padding multiple of 3", fname: "b64encode", value: StringNode("", "Short string"), result: StringNode("", "U2hvcnQgc3RyaW5n")},
 		{name: "b64encode_std_padding remainder 2", fname: "b64encode", value: StringNode("", "A test string"), result: StringNode("", "QSB0ZXN0IHN0cmluZw==")},
@@ -503,7 +504,7 @@ func TestFunctions2(t *testing.T) {
 			valueNode(nil, "", Numeric, "foo"),
 			valueNode(nil, "", Numeric, "foo"),
 		}), fail: true},
-		{name: "sum error 2", fname: "sum", value: _e, fail: false, result: NullNode("")},
+		{name: "sum error 2", fname: "sum", value: _e, fail: true},
 		{name: "sum array 1", fname: "sum", value: ArrayNode("test", []*Node{
 			NumericNode("", 1),
 			NumericNode("", 1),
@@ -522,6 +523,7 @@ func TestFunctions2(t *testing.T) {
 		}), result: NumericNode("", 6)},
 		{name: "sum array blank", fname: "sum", value: ArrayNode("test", []*Node{}), result: NumericNode("", 0)},
 		{name: "sum nil", fname: "sum", value: nil, result: NullNode("")},
+		{name: "sum one", fname: "sum", value: NumericNode("", 123), result: NumericNode("", 123)},
 
 		{name: "rand", fname: "rand", value: StringNode("test", "test"), fail: true},
 		{name: "randint", fname: "randint", value: StringNode("test", "test"), fail: true},