Guard and cache fetchPermission chrome API.

[Hyperkid123]

jira: https://issues.redhat.com/browse/RHCLOUD-9200

Changes

• adds a guard for fetchPermission chrome API call
  • invoking fetchPermission x > 1 times will always result only in one API call.
• use maximum page size for the fetchPermission config
  • previously the page size was 25, now it's 100
  • this change alone reduces the number of calls 4x
• cache the fetchPermission call
  • this will remove many rbac API calls when switching between apps
  • the cache is invalidated after 10 minutes

[codecov-commenter]

Codecov Report

Merging #975 into master will increase coverage by 0.28%.
The diff coverage is 65.21%.

@@            Coverage Diff             @@
##           master     #975      +/-   ##
==========================================
+ Coverage   52.59%   52.88%   +0.28%     
==========================================
  Files          57       57              
  Lines        1061     1076      +15     
  Branches      206      209       +3     
==========================================
+ Hits          558      569      +11     
- Misses        398      402       +4     
  Partials      105      105              

Impacted Files	Coverage Δ
src/js/entry.js	23.94% <0.00%> (-1.06%)	⬇️
src/js/rbac/fetchPermissions.js	74.07% <93.75%> (+14.07%)	⬆️

[karelhala]

I wouldn't create new cache, I'd rather share chrome cache from all over places, meaning passing it to createFetchPermissionsWatcher

const createFetchPermissionsWatcher = (cache) => {
  let currentCall = undefined;
    return async (userToken, app = '') => {
        if (insights.chrome.getBundle() === 'openshift') {
            return Promise.resolve([]);
        }
        const permissions = await cache.getItem('permissions');
        if (permissions) {
            return permissions;
        }
        if (typeof currentCall === 'undefined') {
            currentCall = getUser().then(() => fetchPermissions(userToken, app).then((data) => {
                currentCall = undefined;
                cache.setItem('permissions', data);
                return data;
            }));
        }
        return currentCall;
    };
}

[karelhala]

I'd change this to consume only cahce

const fetchPermissions = getUser().then(() => createFetchPermissionsWatcher(cache));

[karelhala]

In order to make it work correctly you'd have to moce let chromeCache on line 56 move above chrome bootstrap.

[Hyperkid123]

@karelhala I have forgotten to update the tests.

[Hyperkid123]

@karelhala also using the global cache does not work 😢 The endpoint is called before the cache is created... Let's use the local cache for now and I will come up with a solution to make the chrome cache global in a different PR.
This is the error. The cache is, unfortunately undefined.

fetchPermissions.js:69 Uncaught (in promise) TypeError: Cannot read property 'getItem' of undefined
    at _callee$ (fetchPermissions.js:69)
    at tryCatch (runtime.js:63)
    at Generator.invoke [as _invoke] (runtime.js:293)
    at Generator.eval [as next] (runtime.js:118)
    at asyncGeneratorStep (asyncToGenerator.js:3)
    at _next (asyncToGenerator.js:25)
    at eval (asyncToGenerator.js:32)
    at new Promise (<anonymous>)
    at eval (asyncToGenerator.js:21)
    at eval (fetchPermissions.js:101)