return error if field is not found

internal/operator/operators.go

@@ -218,6 +218,10 @@ func GetOperator(name string) Operator {
 }
 
 func convertToNumber(value interface{}) (float64, error) {
+	if value == nil {
+		return 0, nil
+	}
+
 	val := reflect.ValueOf(value)
 	if val.Type().ConvertibleTo(floatType) {
 		return val.Convert(floatType).Float(), nil

internal/parser/parser.go

@@ -69,7 +69,7 @@ func (n *Node) find(path []string) ([]*Node, error) {
 	if n.Type == Object {
 		item := n.mapItems[path[0]]
 		if item == nil {
-			return []*Node{{}}, nil
+			return nil, nil
 		}
 		return item.find(path[1:])
 	} else if n.Type == Array {
@@ -94,7 +94,7 @@ func (n *Node) find(path []string) ([]*Node, error) {
 			return n.listItems[int(index)].find(path[1:])
 		}
 	}
-	return []*Node{{}}, nil
+	return nil, nil
 }
 
 func lookup(in interface{}, parent *Node, path string, index int) *Node {

internal/parser/parser_test.go

@@ -41,7 +41,7 @@ func TestParserFind(t *testing.T) {
 			name:     "scalar-not-found",
 			input:    map[string]interface{}{"my-key": true},
 			key:      "my-key-2",
-			expected: nil,
+			expected: (*Node)(nil),
 		},
 		{
 			name: "map-scalar-string",
@@ -116,7 +116,7 @@ func TestParserFind(t *testing.T) {
 				},
 			},
 			key:      "parent.child.not-found",
-			expected: nil,
+			expected: (*Node)(nil),
 		},
 	}
 
@@ -126,7 +126,11 @@ func TestParserFind(t *testing.T) {
 		if err != nil {
 			t.Error(err)
 		}
-		assert.Equal(t, test.expected, field.Value, "testcase #%d failed", i)
+		if field != nil {
+			assert.Equal(t, test.expected, field.Value, "testcase #%d failed", i)
+		} else {
+			assert.Equal(t, test.expected, field, "testcase #%d failed", i)
+		}
 	}
 }
 

tests/testcases/check.yaml

@@ -21,86 +21,3 @@ tests:
     failed: true
     errors:
     - namespace must be default
-- id: field-failing-check-2
-  input:
-    metadata:
-  result:
-    failed: true
-    errors:
-    - namespace must be default
-
----
-
-id: check-statment-2
-policy:
-  rules:
-  - when:
-      field: metadata.name
-      operator: equal
-      value: app
-    condition:
-      field: metadata.namespace
-      operator: equal
-      value: default
-    result: namespace must be default
-tests:
-- id: field-passing-check
-  input:
-    metadata:
-      name: app
-      namespace: default
-  result:
-    passed: true
-- id: field-passing-check
-  input:
-    metadata:
-      name: test
-      namespace: default
-  result:
-    passed: true
-- id: field-passing-check
-  input:
-    metadata:
-      name: app
-      namespace: test
-  result:
-    failed: true
-    errors:
-    - namespace must be default
-
-
-# id: check-statment-2
-# policy:
-#   rules:
-#   - condition:
-#       expr: default
-#       operator: equal
-#       value: default
-#     result: namespace must be default
-# tests:
-# - id: field-passing-check
-#   input:
-#     metadata:
-#       namespace: default
-#   result:
-#     passed: true
-
-# ---
-
-# id: check-statment-2
-# policy:
-#   rules:
-#   - condition:
-#       expr: ${ .Params.test | upper }
-#       operator: equal
-#       value: DEFAULT
-#     result: namespace must be default
-# tests:
-# - id: field-passing-check
-#   input:
-#     metadata:
-#       namespace: default
-#   params:
-#     test: default
-#   result:
-#     passed: true

yapl/condition.go

@@ -72,6 +72,10 @@ func (c *Condition) Eval(ctx *Context, input *parser.Node) ([]ConditionResult, e
 			return nil, err
 		}
 
+		if fields == nil {
+			return nil, fmt.Errorf("field %s not found", condition.Field)
+		}
+
 		for i := range fields {
 			ctx.Cond.Field = fields[i]
 			value := fields[i].Value