check template summary

ui/tx/interpretation/TxInterpretation.tsx

@@ -17,7 +17,7 @@ import EnsEntity from 'ui/shared/entities/ens/EnsEntity';
 import TokenEntity from 'ui/shared/entities/token/TokenEntity';
 import IconSvg from 'ui/shared/IconSvg';
 
-import { extractVariables, getStringChunks, fillStringVariables, NATIVE_COIN_SYMBOL_VAR_NAME } from './utils';
+import { extractVariables, getStringChunks, fillStringVariables, checkSummary, NATIVE_COIN_SYMBOL_VAR_NAME } from './utils';
 
 type Props = {
   summary?: TxInterpretationSummary;
@@ -116,6 +116,10 @@ const TxInterpretation = ({ summary, isLoading, className }: Props) => {
   const template = summary.summary_template;
   const variables = summary.summary_template_variables;
 
+  if (!checkSummary(template, variables)) {
+    return null;
+  }
+
   const intermediateResult = fillStringVariables(template, variables);
 
   const variablesNames = extractVariables(intermediateResult);

ui/tx/interpretation/utils.test.ts

-import { extractVariables, getStringChunks } from './utils';
+import { extractVariables, getStringChunks, checkSummary } from './utils';
 
 const template = '{action_type} {source_amount} {native} into {destination_amount} {destination_token}';
 
@@ -11,3 +11,15 @@ it('split string without capturing variables', () => {
   const result = getStringChunks(template);
   expect(result).toEqual([ '', ' ', ' ', ' into ', ' ', '' ]);
 });
+
+it('checks that summary is valid', () => {
+  const result = checkSummary('{foo} {bar}', { foo: { type: 'string', value: 'foo' }, bar: { type: 'string', value: 'bar' } });
+  expect(result).toBe(true);
+});
+
+it('checks that summary is invalid', () => {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore:
+  const result = checkSummary('{foo} {bar}', { foo: { type: 'string', value: null }, bar: { type: 'string', value: 'bar' } });
+  expect(result).toBe(false);
+});

ui/tx/interpretation/utils.ts

@@ -20,6 +20,19 @@ export function getStringChunks(template: string) {
   return template.split(VAR_REGEXP);
 }
 
+export function checkSummary(template: string, variables: Record<string, TxInterpretationVariable>) {
+  const variablesNames = extractVariables(template);
+  let result = true;
+  for (const name of variablesNames) {
+    if (!variables[name] || variables[name].value === undefined || variables[name].value === null) {
+      result = false;
+      break;
+    }
+  }
+
+  return result;
+}
+
 export function fillStringVariables(template: string, variables: Record<string, TxInterpretationVariable>) {
   const variablesNames = extractVariables(template);