fix: no literal statement and no merge

src/client/types/expression.type-renderer.jsx

@@ -19,6 +19,7 @@ const decorate = compose(
 const Expression = (props) => {
   const {
     context,
+    isStatement,
     onChange = () => {},
     type,
     value = {},
@@ -60,7 +61,7 @@ const Expression = (props) => {
                         value={op.key}
                       >
                         {
-                          [...options, '<literal>']
+                          options.concat(!isStatement && 0 === i ? '<literal>' : [])
                             .sort((l, r) => (l.toLowerCase() < r.toLowerCase() ? -1 : 1))
                             .map((option) => <option key={option}>{option}</option>)
                         }

src/client/types/expressions.type-renderer.jsx

@@ -27,19 +27,19 @@ const Expressions = ({
                 <li key={i}>
                   <Expression.Component
                     context={context}
-                    onChange={(expressionValue, event) => (
+                    isStatement
+                    onChange={(expressionValue, event) => {
+                      return (
                         onChange({
                           ...value,
                           expressions: [
                             ...expressions.slice(0, i),
-                          {
+                            expressionValue,
-                            ...expressions[i],
-                            ...expressionValue,
-                          },
                             ...expressions.slice(i + 1),
                           ],
                         }, event)
-                    )}
+                      );
+                    }}
                     type="any"
                     value={expression}
                   />