feat(core dom): Add method is_button.

dom.is_button tests, if an element is a button like element.
Button like elements are the following:

    button,
    button[type=button],
    button[type=submit],
    input[type=image],
    input[type=button],
    input[type=reset],
    input[type=submit]

Author: thet

src/core/dom.js

@@ -141,6 +141,24 @@ const is_input = (el) => {
     return re_input.test(el.nodeName);
 };
 
+/**
+ * Test, if a element is a button-like input type.
+ *
+ * @param {Node} el - The DOM node to test.
+ * @returns {Boolean} - True if the element is a input-type element.
+ */
+const is_button = (el) => {
+    return el.matches(`
+        button,
+        input[type=image],
+        input[type=button],
+        input[type=reset],
+        input[type=submit]
+    `);
+};
+
+
+
 /**
  * Return all direct parents of ``el`` matching ``selector``.
  * This matches against all parents but not the element itself.
@@ -613,6 +631,7 @@ const dom = {
     acquire_attribute: acquire_attribute,
     is_visible: is_visible,
     is_input: is_input,
+    is_button: is_button,
     create_from_string: create_from_string,
     get_css_value: get_css_value,
     find_scroll_container: find_scroll_container,

src/core/dom.test.js

@@ -547,6 +547,47 @@ describe("core.dom tests", () => {
         });
     });
 
+    describe("is_button", () => {
+        it("checks, if an element is a button-like element or not.", (done) => {
+
+            const button = document.createElement("button");
+            const button_button = document.createElement("button");
+            button_button.setAttribute("type", "button");
+            const button_submit = document.createElement("button");
+            button_submit.setAttribute("type", "submit");
+
+            const input_button = document.createElement("input");
+            input_button.setAttribute("type", "button");
+            const input_submit = document.createElement("input");
+            input_submit.setAttribute("type", "submit");
+            const input_reset = document.createElement("input");
+            input_reset.setAttribute("type", "reset");
+            const input_image = document.createElement("input");
+            input_image.setAttribute("type", "image");
+
+            expect(dom.is_button(button)).toBe(true);
+            expect(dom.is_button(button_button)).toBe(true);
+            expect(dom.is_button(button_submit)).toBe(true);
+            expect(dom.is_button(input_button)).toBe(true);
+            expect(dom.is_button(input_image)).toBe(true);
+            expect(dom.is_button(input_reset)).toBe(true);
+            expect(dom.is_button(input_submit)).toBe(true);
+
+            const input_text = document.createElement("input");
+            input_text.setAttribute("type", "text");
+
+            expect(dom.is_button(input_text)).toBe(false);
+            expect(dom.is_button(document.createElement("input"))).toBe(false);
+            expect(dom.is_button(document.createElement("select"))).toBe(false);
+            expect(dom.is_button(document.createElement("textarea"))).toBe(false);
+            expect(dom.is_button(document.createElement("form"))).toBe(false);
+            expect(dom.is_button(document.createElement("div"))).toBe(false);
+
+            done();
+        });
+    });
+
+
     describe("create_from_string", () => {
         it("Creates a DOM element from a string", (done) => {
             const res = dom.create_from_string(`