ComboboxControl: Add more unit tests

packages/components/src/combobox-control/test/index.tsx

@@ -188,6 +188,46 @@ describe.each( [
 		expect( input ).toHaveValue( targetOption.label );
 	} );
 
+	it( 'calls onFilterValueChange whenever the textbox changes', async () => {
+		const user = userEvent.setup();
+		const onFilterValueChangeSpy = jest.fn();
+		render(
+			<Component
+				options={ timezones }
+				label={ defaultLabelText }
+				onFilterValueChange={ onFilterValueChangeSpy }
+			/>
+		);
+
+		const input = getInput( defaultLabelText );
+
+		await user.type( input, 'a' );
+		expect( onFilterValueChangeSpy ).toHaveBeenCalledWith( 'a' );
+	} );
+
+	it( 'clears the textbox value if there is no selected value on blur', async () => {
+		const user = userEvent.setup();
+		const onFilterValueChangeSpy = jest.fn();
+		render(
+			<Component
+				options={ timezones }
+				label={ defaultLabelText }
+				onFilterValueChange={ onFilterValueChangeSpy }
+			/>
+		);
+		const input = getInput( defaultLabelText );
+
+		await user.type( input, 'a' );
+		expect( input ).toHaveValue( 'a' );
+
+		// Blur and focus the input.
+		await user.tab();
+		await user.click( input );
+
+		expect( input ).toHaveValue( '' );
+		expect( onFilterValueChangeSpy ).toHaveBeenLastCalledWith( '' );
+	} );
+
 	it( 'should select the correct option from a search', async () => {
 		const user = await userEvent.setup();
 		const targetOption = timezones[ 13 ];