Add schema validation for BranchNode gRPC objects (#248)

* Fixes #140

Co-Authored-By: Chris Li <chris.li.2046@gmail.com>

* Fix validation to allow empty expressions in if conditions

Co-Authored-By: Chris Li <chris.li.2046@gmail.com>

* style: Automated gofmt

Formatted Go code using gofmt.

* Update tests to allow empty expressions in if conditions

Co-Authored-By: Chris Li <chris.li.2046@gmail.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Chris Li <chris.li.2046@gmail.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: 3 people

core/taskengine/vm_runner_branch.go

@@ -32,6 +32,30 @@ func (r *BranchProcessor) Validate(node *avsproto.BranchNode) error {
 		return fmt.Errorf("the first condition need to be an if but got :%s", node.Conditions[0].Type)
 	}
 
+	for i, condition := range node.Conditions {
+		if condition == nil {
+			return fmt.Errorf("condition at index %d is nil", i)
+		}
+
+		if condition.Id == "" {
+			return fmt.Errorf("condition at index %d has empty ID", i)
+		}
+
+		if condition.Type == "" {
+			return fmt.Errorf("condition at index %d has empty type", i)
+		}
+
+		if condition.Type != "if" && condition.Type != "else" {
+			return fmt.Errorf("condition at index %d has invalid type: %s (must be 'if' or 'else')", i, condition.Type)
+		}
+
+		if condition.Type == "else" && i < len(node.Conditions)-1 {
+			if r.vm.logger != nil {
+				r.vm.logger.Warn("'else' condition is not the last one, subsequent conditions will be ignored")
+			}
+		}
+	}
+
 	return nil
 }
 

core/taskengine/vm_runner_branch_test.go

@@ -549,3 +549,99 @@ func TestBranchNodeNoElseSkip(t *testing.T) {
 		})
 	}
 }
+
+func TestBranchNodeMalformedData(t *testing.T) {
+	testCases := []struct {
+		name        string
+		conditions  []*avsproto.Condition
+		expectError bool
+		errorMsg    string
+	}{
+		{
+			name: "nil condition",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				nil,
+			},
+			expectError: true,
+			errorMsg:    "condition at index 1 is nil",
+		},
+		{
+			name: "empty condition ID",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				{Id: "", Type: "if", Expression: "a > 5"},
+			},
+			expectError: true,
+			errorMsg:    "condition at index 1 has empty ID",
+		},
+		{
+			name: "empty condition type",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				{Id: "condition2", Type: "", Expression: "a > 5"},
+			},
+			expectError: true,
+			errorMsg:    "condition at index 1 has empty type",
+		},
+		{
+			name: "invalid condition type",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				{Id: "condition2", Type: "invalid", Expression: "a > 5"},
+			},
+			expectError: true,
+			errorMsg:    "condition at index 1 has invalid type",
+		},
+		{
+			name: "empty if expression",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				{Id: "condition2", Type: "if", Expression: ""},
+			},
+			expectError: false,
+		},
+		{
+			name: "whitespace if expression",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				{Id: "condition2", Type: "if", Expression: "   \t\n  "},
+			},
+			expectError: false,
+		},
+		{
+			name: "valid conditions",
+			conditions: []*avsproto.Condition{
+				{Id: "condition1", Type: "if", Expression: "a > 10"},
+				{Id: "condition2", Type: "if", Expression: "a > 5"},
+				{Id: "condition3", Type: "else"},
+			},
+			expectError: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			vm := NewVM()
+			processor := NewBranchProcessor(vm)
+
+			err := processor.Validate(&avsproto.BranchNode{
+				Conditions: tc.conditions,
+			})
+
+			if tc.expectError {
+				if err == nil {
+					t.Errorf("expected error but got none")
+					return
+				}
+				if !strings.Contains(err.Error(), tc.errorMsg) {
+					t.Errorf("expected error message to contain '%s', but got: '%s'", tc.errorMsg, err.Error())
+				}
+			} else {
+				if err != nil {
+					t.Errorf("unexpected error: %v", err)
+				}
+			}
+		})
+	}
+}