After some brief testing, there were some bad assumptions made about …

…how to update a users opt in status.

Result code id changed from 205 to 130 (Do not text result code).
Cell is checked later down the call chain, so don't need to worry here.
customFields >> custom_fields.
Test is updated to reflect these changes.

__test__/extensions/message-handlers/ngpvan-optout.test.js

@@ -21,8 +21,8 @@ describe("extensions.message-handlers.ngpvan-optout", () => {
 
       contact = {
         message_status: "needsMessage",
-        customFields: '{"vanid": 12345}',
-        cell: "(123)-456-7891"
+        custom_fields: '{"vanid": 12345}',
+        cell: "123-456-7891"
       };
 
       organization = {
@@ -39,11 +39,11 @@ describe("extensions.message-handlers.ngpvan-optout", () => {
             "inputTypeId": 11, // API input
             "phone": {
                 "dialingPrefix": "1",
-                "phoneNumber": "1234567891",
+                "phoneNumber": "123-456-7891",
                 "smsOptInStatus": "O" // opt out status
             }
         },
-        "resultCodeId": 205
+        "resultCodeId": 130
     };
 
       jest.spyOn(Config, "getConfig").mockReturnValue(undefined);
@@ -102,7 +102,7 @@ describe("extensions.message-handlers.ngpvan-optout", () => {
       beforeEach(async () => {
         contact = {
           ...contact,
-          customFields: '{}'
+          custom_fields: '{}'
         };
       });
 

src/extensions/message-handlers/ngpvan-optout/index.js

@@ -47,28 +47,25 @@ export const postMessageSave = async ({
     // we don't want to call that function every time if a vanid
     // was never provided in the first place. Example: CSV
     try {
-        customField = JSON.parse(contact.customFields);
+        customField = JSON.parse(contact.custom_fields);
         vanId = customField.VanID || customField.vanid;
         if (!vanId) return {}
     } catch (exception) {
         console.log("message-handlers | ngpvan-optout ERROR", exception);
         return {};
     }
 
-    // Testing shows that "-" , "(", and ")" break this request
-    const cell = contact.cell.replace(/\D/g,'')
-
     // https://docs.ngpvan.com/reference/peoplevanidcanvassresponses
     const body = {
         "canvassContext": {
             "inputTypeId": 11, // API input
             "phone": {
                 "dialingPrefix": "1",
-                "phoneNumber": cell,
+                "phoneNumber": contact.cell,
                 "smsOptInStatus": "O" // opt out status
             }
         },
-        "resultCodeId": 205
+        "resultCodeId": 130 // Do Not Text result code
     };
 
     return Van.postCanvassResponse(contact, organization, body)