fix(ui5-input): fire submit only if single input in a form (#12244)

* fix(ui5-input): fire submit only if single input in a form

to match the native input in form behavior, the submit event should
be fired on enter key press and change event only if there is a single
input in the form.

fixes: #12221

Author: ndeshev

packages/main/cypress/specs/Input.cy.tsx

@@ -198,6 +198,35 @@ describe("Input Tests", () => {
 		cy.get("@change").should("have.been.calledOnce");
 	});
 
+	it("should not fire 'submit' event when there is more than one input field in a form", () => {
+		cy.mount(
+			<form>
+				<Input id="first-input" onChange={cy.stub().as("change")}></Input>
+				<Input></Input>
+			</form>
+		);
+
+		// spy submit event and prevent it
+		cy.get("form")
+			.then($form => {
+				$form.get(0).addEventListener("submit", cy.spy().as("submit"));
+			});
+
+		// check if submit is triggered after change
+		cy.get("#first-input")
+			.as("input")
+			.realClick();
+
+		cy.get("@input")
+			.should("be.focused");
+
+		cy.realType("test");
+
+		cy.realPress("Enter");
+
+		cy.get("@submit").should("have.not.been.called");
+	});
+
 	it("tests if pressing enter twice fires submit 2 times and change once", () => {
 		cy.mount(
 			<form>

packages/main/src/Input.ts

@@ -837,9 +837,11 @@ class Input extends UI5Element implements SuggestionComponent, IFormInputElement
 
 		if (isEnter(e)) {
 			const isValueUnchanged = this.previousValue === this.getInputDOMRefSync()!.value;
+			const shouldSubmit = this._internals.form && this._internals.form.querySelectorAll("[ui5-input]").length === 1;
+
 			this._enterKeyDown = true;
 
-			if (isValueUnchanged && this._internals.form) {
+			if (isValueUnchanged && shouldSubmit) {
 				submitForm(this);
 			}
 
@@ -1138,6 +1140,8 @@ class Input extends UI5Element implements SuggestionComponent, IFormInputElement
 	}
 
 	_handleChange() {
+		const shouldSubmit = this._internals.form && this._internals.form.querySelectorAll("[ui5-input]").length === 1;
+
 		if (this._clearIconClicked) {
 			this._clearIconClicked = false;
 			return;
@@ -1159,7 +1163,7 @@ class Input extends UI5Element implements SuggestionComponent, IFormInputElement
 			} else {
 				fireChange();
 
-				if (this._enterKeyDown && this._internals.form) {
+				if (this._enterKeyDown && shouldSubmit) {
 					submitForm(this);
 				}
 			}