From a01b53ca38fa1ea1a61f4af7a6fb3d83d6bf7a8d Mon Sep 17 00:00:00 2001
From: Nick Milton <nickdjm@gmail.com>
Date: Wed, 8 May 2024 16:07:53 -0400
Subject: [PATCH] feat(treeview): handle aria-expanded true on load

See #268
---
 docs/api/treeview-toggle.md                  |  24 ++-
 src/treeviewToggle.js                        |  64 ++++++++
 tests/menus/TreeviewToggle/protected.test.js | 164 ++++++++++++++++++-
 3 files changed, 244 insertions(+), 8 deletions(-)

diff --git a/docs/api/treeview-toggle.md b/docs/api/treeview-toggle.md
index ec56c08..37a6372 100644
--- a/docs/api/treeview-toggle.md
+++ b/docs/api/treeview-toggle.md
@@ -37,7 +37,15 @@ The constructor will call [BaseMenuToggle's constructor](./base-menu-toggle#cons
 
 ## Initialize
 
-The initialize method is inherited from the [BaseMenuToggle](./base-menu-toggle#initialize) class. There are no customizations for the TreeviewToggle class.
+Initializes the menu toggle.
+
+```js
+TreeviewToggle.initialize();
+```
+
+The first steps are to ensure that the toggle and controlled menu have IDs using the [setIds](./base-menu-toggle#method--setIds) method, and to set the ARIA attributes on the toggle and controlled menu using the [setAriaAttributes](#method--setAriaAttributes) method.
+
+Then the [open](./base-menu-toggle#method--open) or [collapse](./base-menu-toggle#method--collapse) method is called based on the state of the toggle's aria-expanded attribute.
 
 ## Properties
 
@@ -49,4 +57,16 @@ Getters and setters are inherited from the [BaseMenuToggle](./base-menu-toggle#g
 
 ## Methods
 
-Methods are inherited from the [BaseMenuToggle](./base-menu-toggle#methods) class. There are no custom methods for the TreeviewToggle class.
+Methods are inherited from the [BaseMenuToggle](./base-menu-toggle#methods) class. The following methods are unique to or overwritten in the TreeviewToggle class.
+
+### _setAriaAttributes <badge type="warning" text="protected" /> {#method--setAriaAttributes}
+
+Sets the ARIA attributes on the toggle and controlled menu.
+
+```js
+TreeviewToggle._setAriaAttributes();
+```
+
+The first steps are to ensure that the toggle has `aria-haspopup` set to "true", `aria-expanded` set to "false" if it's not already set explicitly to "true", and if the toggle element is not a `<button>`, set the `role` to "button".
+
+Then using the toggle and menu's IDs, the menu's `aria-labelledby` is set to the toggle's ID, and the toggle's `aria-controls` is set to the menu's ID.
diff --git a/src/treeviewToggle.js b/src/treeviewToggle.js
index bfd9092..d0a80f1 100644
--- a/src/treeviewToggle.js
+++ b/src/treeviewToggle.js
@@ -2,6 +2,7 @@
 /* global Treeview */
 
 import BaseMenuToggle from "./_baseMenuToggle.js";
+import { isTag } from "./validate.js";
 
 /**
  * A link or button that controls the visibility of a Treeview.
@@ -37,6 +38,69 @@ class TreeviewToggle extends BaseMenuToggle {
       this.initialize();
     }
   }
+
+  /**
+   * Initializes the menu toggle.
+   *
+   * The first steps are to ensure that the toggle and controlled menu have IDs
+   * using the setIds method, and to set the ARIA attributes on the toggle
+   * and controlled menu using the setAriaAttributes method.
+   *
+   * Then the open or collapse method is called based on the state of the
+   * toggle's aria-expanded attribute.
+   */
+  initialize() {
+    // Ensure both toggle and menu have IDs.
+    this._setIds();
+
+    // Set ARIA attributes.
+    this._setAriaAttributes();
+
+    // Open the menu if aria-expanded is true, otherwise collapse it.
+    if (this.dom.toggle.getAttribute("aria-expanded") === "true") {
+      this.open();
+    } else {
+      this._collapse(false);
+    }
+  }
+
+  /**
+   * Sets the ARIA attributes on the toggle and controlled menu.
+   *
+   * The first steps are to ensure that the toggle has `aria-haspopup`
+   * set to "true", `aria-expanded` set to "false" if it's not already
+   * set explicitly to "true", and if the toggle element is not a `<button>`,
+   * set the `role` to "button".
+   *
+   * Then using the toggle and menu's IDs, the menu's `aria-labelledby` is set to
+   * the toggle's ID, and the toggle's `aria-controls` is set to the menu's ID.
+   *
+   * @protected
+   */
+  _setAriaAttributes() {
+    // Set up proper aria attributes.
+    this.dom.toggle.setAttribute("aria-haspopup", "true");
+
+    // If the toggle element doesn't have aria-expanded set to true, set it to false.
+    if (this.dom.toggle.getAttribute("aria-expanded") !== "true") {
+      this.dom.toggle.setAttribute("aria-expanded", "false");
+    }
+
+    // If the toggle element is a button, there's no need to add a role.
+    if (!isTag("button", { toggle: this.dom.toggle })) {
+      this.dom.toggle.setAttribute("role", "button");
+    }
+
+    // Set up proper aria label and control.
+    this.elements.controlledMenu.dom.menu.setAttribute(
+      "aria-labelledby",
+      this.dom.toggle.id
+    );
+    this.dom.toggle.setAttribute(
+      "aria-controls",
+      this.elements.controlledMenu.dom.menu.id
+    );
+  }
 }
 
 export default TreeviewToggle;
diff --git a/tests/menus/TreeviewToggle/protected.test.js b/tests/menus/TreeviewToggle/protected.test.js
index adbad6d..9662254 100644
--- a/tests/menus/TreeviewToggle/protected.test.js
+++ b/tests/menus/TreeviewToggle/protected.test.js
@@ -2,10 +2,20 @@
  * Tests for protected methods in the TreeviewToggle class.
  */
 
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { twoLevel } from "../../../demo/menus.js";
+import Treeview from "../../../src/treeview.js";
 import TreeviewToggle from "../../../src/treeviewToggle.js";
 import BaseMenuToggle from "../../../src/_baseMenuToggle.js";
 
+beforeEach(() => {
+  document.body.innerHTML = twoLevel;
+});
+
+afterEach(() => {
+  document.body.innerHTML = "";
+});
+
 // Test TreeviewToggle protected methods.
 describe("TreeviewToggle protected methods", () => {
   // Test TreeviewToggle _expand().
@@ -38,13 +48,155 @@ describe("TreeviewToggle protected methods", () => {
     });
   });
 
-  // Test TreeviewToggle _setAriaAttributes().
   describe("_setAriaAttributes", () => {
-    // Test that TreeviewToggle implements the BaseMenuToggle _setAriaAttributes.
-    it("should implement the BaseMenuToggle _setAriaAttributes", () => {
-      expect(TreeviewToggle.prototype._setAriaAttributes).toBe(
-        BaseMenuToggle.prototype._setAriaAttributes
+    // Test that _setAriaAttributes sets the toggle's aria-haspopup attribute to true.
+    it("should set the toggle's aria-haspopup attribute to true", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.removeAttribute("aria-haspopup");
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the toggle's aria-haspopup attribute.
+      expect(menuToggle.dom.toggle.getAttribute("aria-haspopup")).toBe("true");
+    });
+
+    // Test that _setAriaAttributes sets the toggle's aria-expanded attribute to false if it is not set.
+    it("should set the toggle's aria-expanded attribute to false if it is not set", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.removeAttribute("aria-expanded");
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the toggle's aria-expanded attribute.
+      expect(menuToggle.dom.toggle.getAttribute("aria-expanded")).toBe("false");
+    });
+
+    // Test that _setAriaAttributes does not change the toggle's aria-expanded attribute if it is already set to true.
+    it("should not change the toggle's aria-expanded attribute if it is already set to true", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.setAttribute("aria-expanded", "true");
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the toggle's aria-expanded attribute.
+      expect(menuToggle.dom.toggle.getAttribute("aria-expanded")).toBe("true");
+    });
+
+    // Test that _setAriaAttributes sets the toggle's aria-expanded role to false if it is set to anything other than true.
+    it("should set the toggle's aria-expanded role to false if it is set to anything other than true", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.setAttribute("aria-expanded", "invalid");
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the toggle's aria-expanded attribute.
+      expect(menuToggle.dom.toggle.getAttribute("aria-expanded")).toBe("false");
+    });
+
+    // Test that _setAriaAttributes sets the toggle's role attribute to button if the toggle is not a button.
+    // @todo Make a test for when the toggle _is_ a button. This will require a new menu template.
+    it("should set the toggle's role attribute to button if the toggle is not a button", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.removeAttribute("role");
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the toggle's role attribute.
+      expect(menuToggle.dom.toggle.getAttribute("role")).toBe("button");
+    });
+
+    // Test that _setAriaAttributes sets the toggle's aria-controls attribute to the controlled menu's id.
+    it("should set the toggle's aria-controls attribute to the controlled menu's id", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.removeAttribute("aria-controls");
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the toggle's aria-controls attribute.
+      expect(menuToggle.dom.toggle.getAttribute("aria-controls")).toBe(
+        menuToggle.elements.controlledMenu.dom.menu.id
       );
     });
+
+    // Test that _setAriaAttributes sets the controlled menu's aria-labelledby attribute to the toggle's id.
+    it("should set the controlled menu's aria-labelledby attribute to the toggle's id", () => {
+      // Create a new Treeview instance for testing.
+      const menu = new Treeview({
+        menuElement: document.querySelector("ul"),
+        submenuItemSelector: "li.dropdown",
+        containerElement: document.querySelector("nav"),
+        controllerElement: document.querySelector("button"),
+      });
+
+      const menuToggle = menu.elements.submenuToggles[0];
+      menuToggle.dom.toggle.removeAttribute("id");
+      menuToggle.elements.controlledMenu.dom.menu.removeAttribute(
+        "aria-labelledby"
+      );
+
+      // Call _setAriaAttributes.
+      menuToggle._setAriaAttributes();
+
+      // Test the controlled menu's aria-labelledby attribute.
+      expect(
+        menuToggle.elements.controlledMenu.dom.menu.getAttribute(
+          "aria-labelledby"
+        )
+      ).toBe(menuToggle.dom.toggle.id);
+    });
   });
 });