Added integration with limit service

refs https://github.com/TryGhost/Team/issues/587

- This is first pass on the frontend limit-service integration. Max count queries are substituted with HTTP requests to mimick backend checks. Note, they are not meant to substitute backend checks only to suplment them.

ghost/admin/app/services/limit.js

@@ -0,0 +1,86 @@
+import LimitService from '@tryghost/limit-service';
+import RSVP from 'rsvp';
+import Service, {inject as service} from '@ember/service';
+import {bind} from '@ember/runloop';
+
+class LimitError {
+    constructor({errorType, errorDetails, message}) {
+        this.errorType = errorType;
+        this.errorDetails = errorDetails;
+        this.message = message;
+    }
+}
+
+class IncorrectUsageError extends LimitError {
+    constructor(options) {
+        super(Object.assign({errorType: 'IncorrectUsageError'}, options));
+    }
+}
+
+class HostLimitError extends LimitError {
+    constructor(options) {
+        super(Object.assign({errorType: 'HostLimitError'}, options));
+    }
+}
+
+export default class LimitsService extends Service {
+    @service config;
+    @service store;
+    @service membersStats;
+
+    constructor() {
+        super(...arguments);
+
+        let limits = this.config.get('hostSettings.limits');
+
+        if (limits && !this.limiter) {
+            this.limiter = new LimitService();
+
+            let helpLink;
+
+            if (this.config.get('hostSettings.billing.enabled')
+                && this.config.get('hostSettings.billing.enabled') === true
+                && this.config.get('hostSettings.billing.url')) {
+                helpLink = this.config.get('hostSettings.billing.url');
+            } else {
+                helpLink = 'https://ghost.org/help/';
+            }
+
+            return this.limiter.loadLimits({
+                limits: this.decorateWithCountQueries(limits),
+                helpLink,
+                errors: {
+                    HostLimitError,
+                    IncorrectUsageError
+                }
+            });
+        }
+    }
+
+    decorateWithCountQueries(limits) {
+        if (limits.staff) {
+            limits.staff.currentCountQuery = bind(this, this.getStaffUsersCount);
+        }
+
+        if (limits.members) {
+            limits.members.currentCountQuery = bind(this, this.getMembersCount);
+        }
+
+        return limits;
+    }
+
+    async getStaffUsersCount() {
+        return RSVP.hash({
+            users: this.store.findAll('user', {reload: true}),
+            invites: this.store.findAll('invite', {reload: true})
+        }).then((data) => {
+            return data.users.length + data.invites.length;
+        });
+    }
+
+    async getMembersCount() {
+        const counts = await this.membersStats.fetchCounts();
+
+        return counts.total;
+    }
+}

ghost/admin/package.json

@@ -33,6 +33,7 @@
     "@tryghost/helpers": "1.1.37",
     "@tryghost/kg-clean-basic-html": "1.0.11",
     "@tryghost/kg-parser-plugins": "1.1.0",
+    "@tryghost/limit-service": "0.4.0",
     "@tryghost/members-csv": "0.4.2",
     "@tryghost/mobiledoc-kit": "0.12.5-ghost.1",
     "@tryghost/string": "0.1.16",

ghost/admin/tests/unit/services/limit-test.js

@@ -0,0 +1,17 @@
+import {describe, it} from 'mocha';
+import {expect} from 'chai';
+import {setupTest} from 'ember-mocha';
+
+describe('Unit | Service | limit', function () {
+    setupTest();
+
+    let limitService;
+
+    beforeEach(function () {
+        limitService = this.owner.lookup('service:limit');
+    });
+
+    it('exists', function () {
+        expect(limitService).to.be.ok;
+    });
+});

ghost/admin/yarn.lock

@@ -1760,6 +1760,13 @@
   dependencies:
     "@tryghost/kg-clean-basic-html" "^1.0.11"
 
+"@tryghost/limit-service@0.4.0":
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/@tryghost/limit-service/-/limit-service-0.4.0.tgz#a681eb866171a6966162db87ae0d18ccb1fbb965"
+  integrity sha512-DVWYiKgvXzWqi+L2jJPhTQLogiRZUJw+bX9XMmLg202rnNAn8A9eYIAmWu5TbY4Gp0+6gz6IZFdIIocGDtA8Aw==
+  dependencies:
+    lodash "^4.17.21"
+
 "@tryghost/members-csv@0.4.2":
   version "0.4.2"
   resolved "https://registry.yarnpkg.com/@tryghost/members-csv/-/members-csv-0.4.2.tgz#af6189ea30a18b7ebe1f67c442d459ea8ef7aff9"
@@ -10287,6 +10294,11 @@ lodash@^4.11.1, lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
   integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
 
+lodash@^4.17.21:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
+
 log-symbols@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/log-symbols/-/log-symbols-2.2.0.tgz#5740e1c5d6f0dfda4ad9323b5332107ef6b4c40a"