feat(Merge Node): Overhaul, v3 (#9528)

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>
Co-authored-by: Shireen Missi <94372015+ShireenMissi@users.noreply.github.com>

packages/nodes-base/nodes/Merge/v3/actions/mode/combineByPosition.ts

@@ -0,0 +1,125 @@
+import {
+	NodeExecutionOutput,
+	type IExecuteFunctions,
+	type INodeExecutionData,
+	type INodeProperties,
+	type IPairedItemData,
+} from 'n8n-workflow';
+
+import { updateDisplayOptions } from '@utils/utilities';
+
+import type { ClashResolveOptions } from '../../helpers/interfaces';
+import { clashHandlingProperties, numberInputsProperty } from '../../helpers/descriptions';
+import { addSuffixToEntriesKeys, selectMergeMethod } from '../../helpers/utils';
+
+import merge from 'lodash/merge';
+
+export const properties: INodeProperties[] = [
+	numberInputsProperty,
+	{
+		displayName: 'Options',
+		name: 'options',
+		type: 'collection',
+		placeholder: 'Add Option',
+		default: {},
+		options: [
+			{
+				...clashHandlingProperties,
+				default: { values: { resolveClash: 'addSuffix' } },
+			},
+			{
+				displayName: 'Include Any Unpaired Items',
+				name: 'includeUnpaired',
+				type: 'boolean',
+				default: false,
+				description:
+					'Whether unpaired items should be included in the result when there are differing numbers of items among the inputs',
+			},
+		],
+	},
+];
+
+const displayOptions = {
+	show: {
+		mode: ['combine'],
+		combineBy: ['combineByPosition'],
+	},
+};
+
+export const description = updateDisplayOptions(displayOptions, properties);
+
+export async function execute(
+	this: IExecuteFunctions,
+	inputsData: INodeExecutionData[][],
+): Promise<INodeExecutionData[]> {
+	const returnData: INodeExecutionData[] = [];
+
+	const clashHandling = this.getNodeParameter(
+		'options.clashHandling.values',
+		0,
+		{},
+	) as ClashResolveOptions;
+	const includeUnpaired = this.getNodeParameter('options.includeUnpaired', 0, false) as boolean;
+
+	let preferredInputIndex: number;
+
+	if (clashHandling?.resolveClash?.includes('preferInput')) {
+		preferredInputIndex = Number(clashHandling.resolveClash.replace('preferInput', '')) - 1;
+	} else {
+		preferredInputIndex = inputsData.length - 1;
+	}
+
+	const preferred = inputsData[preferredInputIndex];
+
+	if (clashHandling.resolveClash === 'addSuffix') {
+		for (const [inputIndex, input] of inputsData.entries()) {
+			inputsData[inputIndex] = addSuffixToEntriesKeys(input, String(inputIndex + 1));
+		}
+	}
+
+	let numEntries: number;
+	if (includeUnpaired) {
+		numEntries = Math.max(...inputsData.map((input) => input.length), preferred.length);
+	} else {
+		numEntries = Math.min(...inputsData.map((input) => input.length), preferred.length);
+		if (numEntries === 0) {
+			return new NodeExecutionOutput(
+				[returnData],
+				[
+					{
+						message:
+							'Consider enabling "Include Any Unpaired Items" in options or check your inputs',
+					},
+				],
+			);
+		}
+	}
+
+	const mergeIntoSingleObject = selectMergeMethod(clashHandling);
+
+	for (let i = 0; i < numEntries; i++) {
+		const preferredEntry = preferred[i] ?? {};
+		const restEntries = inputsData.map((input) => input[i] ?? {});
+
+		const json = {
+			...mergeIntoSingleObject(
+				{},
+				...restEntries.map((entry) => entry.json ?? {}),
+				preferredEntry.json ?? {},
+			),
+		};
+
+		const binary = {
+			...merge({}, ...restEntries.map((entry) => entry.binary ?? {}), preferredEntry.binary ?? {}),
+		};
+
+		const pairedItem = [
+			...restEntries.map((entry) => entry.pairedItem as IPairedItemData).flat(),
+			preferredEntry.pairedItem as IPairedItemData,
+		].filter((item) => item !== undefined);
+
+		returnData.push({ json, binary, pairedItem });
+	}
+
+	return returnData;
+}