LWS-261: Codemirror extension for preventing newlines

packages/supersearch/e2e/supersearch.spec.ts

@@ -23,3 +23,20 @@ test('submits form identified by form attribute on enter key press', async ({ pa
 	await page.keyboard.press('Enter');
 	await expect(page).toHaveURL('/test2?q=hello+world');
 });
+
+test('prevents new line characters (e.g. when pasting multi-lined text', async ({
+	page,
+	context
+}) => {
+	await context.grantPermissions(['clipboard-read', 'clipboard-write']);
+	await page.locator('[data-test-id="test1"]').getByRole('textbox').locator('div').click();
+	await page.evaluate(() =>
+		navigator.clipboard.writeText(`One
+      two
+      three`)
+	);
+	await page.keyboard.press(`ControlOrMeta+v`);
+	await expect(page.locator('[data-test-id="test1"]').getByRole('textbox').locator('div')).toHaveText(
+		'One two three'
+	);
+});

packages/supersearch/src/lib/components/SuperSearch.svelte

@@ -4,6 +4,7 @@
 	import { Compartment } from '@codemirror/state';
 	import { type LRLanguage } from '@codemirror/language';
 	import submitFormOnEnterKey from '$lib/extensions/submitFormOnEnterKey.js';
+	import preventNewLine from '$lib/extensions/preventNewLine.js';
 
 	interface Props {
 		name: string;
@@ -22,6 +23,7 @@
 
 	const extensions = [
 		submitFormOnEnterKey(form),
+		preventNewLine({ replaceWithSpace: true }),
 		...(language ? [language] : []),
 		placeholderCompartment.of(placeholderExtension(placeholder))
 	];

packages/supersearch/src/lib/extensions/preventNewLine.ts

@@ -0,0 +1,30 @@
+import { EditorState, Prec } from '@codemirror/state';
+
+/**
+ * CodeMirror extension thats prevents inserted newlines (either by typing or pasting).
+ *
+ * @param {boolean} replaceWithSpace Controls if newline characters should be replaced with spaces.
+ */
+
+const preventNewLine = ({ replaceWithSpace = false }: { replaceWithSpace: boolean }) =>
+	Prec.highest(
+		EditorState.transactionFilter.of((tr) => {
+			if (tr.newDoc.lines > 1) {
+				return [
+					tr,
+					{
+						changes: {
+							from: 0,
+							to: tr.newDoc.length,
+							insert: tr.newDoc.sliceString(0, undefined, replaceWithSpace ? ' ' : '') // flatten multi-lined text
+						},
+						sequential: true
+					}
+				];
+			} else {
+				return [tr];
+			}
+		})
+	);
+
+export default preventNewLine;