Select all works as requirements specify

app/components/file-table.js

@@ -1,4 +1,5 @@
 import Component from '@ember/component';
+import { set } from '@ember/object';
 
 const defaultFiles = [];
 const defaultSelectedFilePaths = [];
@@ -8,6 +9,13 @@ export default Component.extend({
   selectedFilePaths: defaultSelectedFilePaths,
 
   actions: {
+    toggleSelectAll() {
+      if (this.selectedFilePaths.length === this.files.length) {
+        set(this, 'selectedFilePaths', defaultSelectedFilePaths);
+      } else {
+        set(this, 'selectedFilePaths', this.files.map(file => file.path));
+      }
+    },
     toggleSelectedPath(path) {
       if (!this.selectedFilePaths.includes(path)) {
         this.selectedFilePaths.pushObject(path);

app/templates/components/file-table.hbs

@@ -1,7 +1,10 @@
 <header data-test-id="file-table-action-bar">
-  <label data-test-action="file-table-select-all">
+  <button
+    data-test-action="file-table-select-all"
+    {{action "toggleSelectAll"}}
+  >
     Selected {{selectedFilePaths.length}}
-  </label>
+  </button>
   <button data-test-action="file-table-download-selected">Download Selected</button>
 </header>
 

tests/integration/components/file-table-test.js

@@ -3,11 +3,12 @@ import { setupRenderingTest } from 'ember-qunit';
 import { render, find, findAll, click } from '@ember/test-helpers';
 import hbs from 'htmlbars-inline-precompile';
 
+const randomNumber = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;
 const genericFile = () => {
   return {
     name: 'foo.bar',
     device: 'Baz',
-    path: '~/foo.bar',
+    path: `~/foo{${randomNumber(1,9001)}.bar`,
     status: 'available',
   };
 };
@@ -47,4 +48,30 @@ module('Integration | Component | file-table', function(hooks) {
     assert.equal(find('[data-test-action=file-table-select-all]').textContent.trim(), 'Selected 0');
     assert.equal(find('[data-test-id=file-table-item-selected]').textContent.trim(), '', 'Unselected after second click');
   });
+
+  test('select all, with none selected', async function(assert) {
+    this.set('files', [genericFile(), genericFile()]);
+    await render(hbs`{{file-table files=files}}`);
+
+    await click('[data-test-action=file-table-select-all]');
+    assert.equal(find('[data-test-action=file-table-select-all]').textContent.trim(), 'Selected ' + this.files.length);
+  });
+
+  test('select all, with everything selected', async function(assert) {
+    this.set('files', [genericFile(), genericFile()]);
+    this.set('selectedFilePaths', this.files.map(file => file.path));
+    await render(hbs`{{file-table files=files selectedFilePaths=selectedFilePaths}}`);
+
+    await click('[data-test-action=file-table-select-all]');
+    assert.equal(find('[data-test-action=file-table-select-all]').textContent.trim(), 'Selected 0');
+  });
+
+  test('select all, with some selected', async function(assert) {
+    this.set('files', [genericFile(), genericFile()]);
+    this.set('selectedFilePaths', [this.files[0].path]);
+    await render(hbs`{{file-table files=files selectedFilePaths=selectedFilePaths}}`);
+
+    await click('[data-test-action=file-table-select-all]');
+    assert.equal(find('[data-test-action=file-table-select-all]').textContent.trim(), 'Selected ' + this.files.length);
+  });
 });