Make sure unsupported config property types are dropped

Author: colinrotherham

packages/nhsuk-frontend/src/nhsuk/common/configuration/normalise-string.jsdom.test.mjs

@@ -147,11 +147,11 @@ describe('normaliseString', () => {
 
     // Arrays in strings are ignored even with schema property type
     expect(normaliseString(inputArray)).toBe(inputArray)
-    expect(normaliseString(inputArray, { type: 'array' })).toBe(inputArray)
+    expect(normaliseString(inputArray, { type: 'array' })).toBeUndefined()
 
     // Objects in strings are ignored even with schema property type
     expect(normaliseString(inputObject)).toBe(inputObject)
-    expect(normaliseString(inputObject, { type: 'object' })).toBe(inputObject)
+    expect(normaliseString(inputObject, { type: 'object' })).toBeUndefined()
   })
 })
 

packages/nhsuk-frontend/src/nhsuk/common/configuration/normalise-string.mjs

@@ -14,7 +14,10 @@
  * @returns Normalised data
  */
 export function normaliseString(value, property) {
-  if (!isValid(value)) {
+  if (
+    !isValid(value) ||
+    (property?.type && !['string', 'number', 'boolean'].includes(property.type))
+  ) {
     return
   }