feat: Add once for each item support for JS task runner (no-changelog) (#11109)

packages/nodes-base/nodes/Code/JsCodeValidator.ts

@@ -0,0 +1,54 @@
+import { ValidationError } from './ValidationError';
+
+/**
+ * Validates that no disallowed methods are used in the
+ * runCodeForEachItem JS code. Throws `ValidationError` if
+ * a disallowed method is found.
+ */
+export function validateNoDisallowedMethodsInRunForEach(code: string, itemIndex: number) {
+	const match = code.match(/\$input\.(?<disallowedMethod>first|last|all|itemMatching)/);
+
+	if (match?.groups?.disallowedMethod) {
+		const { disallowedMethod } = match.groups;
+
+		const lineNumber =
+			code.split('\n').findIndex((line) => {
+				return line.includes(disallowedMethod) && !line.startsWith('//') && !line.startsWith('*');
+			}) + 1;
+
+		const disallowedMethodFound = lineNumber !== 0;
+
+		if (disallowedMethodFound) {
+			throw new ValidationError({
+				message: `Can't use .${disallowedMethod}() here`,
+				description: "This is only available in 'Run Once for All Items' mode",
+				itemIndex,
+				lineNumber,
+			});
+		}
+	}
+}
+
+/**
+ * Checks if the error message indicates that `items` is not defined and
+ * modifies the error message to suggest using `$input.all()`.
+ */
+export function mapItemsNotDefinedErrorIfNeededForRunForAll(code: string, error: Error) {
+	// anticipate user expecting `items` to pre-exist as in Function Item node
+	if (error.message === 'items is not defined' && !/(let|const|var) +items +=/.test(code)) {
+		const quoted = error.message.replace('items', '`items`');
+		error.message = (quoted as string) + '. Did you mean `$input.all()`?';
+	}
+}
+
+/**
+ * Maps the "item is not defined" error message to provide a more helpful suggestion
+ * for users who may expect `items` to pre-exist
+ */
+export function mapItemNotDefinedErrorIfNeededForRunForEach(code: string, error: Error) {
+	// anticipate user expecting `items` to pre-exist as in Function Item node
+	if (error.message === 'item is not defined' && !/(let|const|var) +item +=/.test(code)) {
+		const quoted = error.message.replace('item', '`item`');
+		error.message = (quoted as string) + '. Did you mean `$input.item.json`?';
+	}
+}