fix(tracking-service): replace drop task modifier

The dropTask modifier prevent multiple instance in the timesheet
overview from fetching their data for the task selection dropdown.
With the renewed logic, it will prevent fetching the same query
multiple times.

Author: derrabauke

app/components/report-row/component.js

@@ -1,29 +1,13 @@
-/**
- * @module timed
- * @submodule timed-components
- * @public
- */
-
 import { action } from "@ember/object";
 import { inject as service } from "@ember/service";
 import Component from "@glimmer/component";
-import { tracked } from "@glimmer/tracking";
 import ReportValidations from "timed/validations/report";
 
-/**
- * Component for the editable report row
- *
- * @class ReportRowComponent
- * @extends Ember.Component
- * @public
- */
 export default class ReportRowComponent extends Component {
   @service abilities;
 
   ReportValidations = ReportValidations;
 
-  @tracked task;
-
   get editable() {
     return this.abilities.can("edit report", this.args.report);
   }

app/services/tracking.js

@@ -288,13 +288,22 @@ export default class TrackingService extends Service {
    * @param {Number} customer The customer id to filter by
    * @public
    */
-  @dropTask
+  @task
   *projects(customer) {
     if (!customer) {
       // We can't test this because the UI prevents it
       throw new Error("No customer selected");
     }
 
+    const original = this.filterDuplicateTasks(this.projects, customer);
+    if (original) {
+      return yield original;
+    }
+
+    // Give it 100ms to "collect" similar requests and
+    // increases the efficiency even more.
+    yield timeout(100);
+
     return yield this.store.query("project", { customer });
   }
 
@@ -305,13 +314,38 @@ export default class TrackingService extends Service {
    * @param {Number} project The project id to filter by
    * @public
    */
-  @dropTask
+  @task
   *tasks(project) {
     if (!project) {
       // We can't test this because the UI prevents it
       throw new Error("No project selected");
     }
 
+    const original = this.filterDuplicateTasks(this.tasks, project);
+    if (original) {
+      return yield original;
+    }
+
+    // Give it 100ms to "collect" similar requests and
+    // increases the efficiency even more.
+    yield timeout(100);
+
     return yield this.store.query("task", { project });
   }
+
+  /**
+   * Filters running tasks with the same arguments and returns the first
+   * task with matching arguments if there is more than one concurrent
+   * instance of it. Otherwise returns undefined.
+   */
+  filterDuplicateTasks(task, argument) {
+    const taskInstances = task.scheduler.taskInstances;
+    if (
+      taskInstances.length > 1 &&
+      taskInstances.filter((task) => task.args[0] === argument).length > 1
+    ) {
+      /* istanbul ignore next */
+      return taskInstances.find((task) => task.args[0] === argument);
+    }
+  }
 }