feat(core): Improvements/overhaul for nodes working with binary data (#7651)

Github issue / Community forum post (link here to close automatically):

---------

Co-authored-by: Giulio Andreini <andreini@netseven.it>
Co-authored-by: Marcus <marcus@n8n.io>

packages/nodes-base/nodes/Files/ReadWriteFile/actions/write.operation.ts

@@ -0,0 +1,123 @@
+import type { IExecuteFunctions, INodeExecutionData, INodeProperties } from 'n8n-workflow';
+import { BINARY_ENCODING } from 'n8n-workflow';
+
+import type { Readable } from 'stream';
+
+import { updateDisplayOptions } from '@utils/utilities';
+import { errorMapper } from '../helpers/utils';
+
+export const properties: INodeProperties[] = [
+	{
+		displayName: 'File Path and Name',
+		name: 'fileName',
+		type: 'string',
+		default: '',
+		required: true,
+		placeholder: 'e.g. /data/example.jpg',
+		description:
+			'Path and name of the file that should be written. Also include the file extension.',
+	},
+	{
+		displayName: 'Input Binary Field',
+		name: 'dataPropertyName',
+		type: 'string',
+		default: 'data',
+		placeholder: 'e.g. data',
+		required: true,
+		hint: 'The name of the input binary field containing the file to be written',
+	},
+	{
+		displayName: 'Options',
+		name: 'options',
+		type: 'collection',
+		placeholder: 'Add Option',
+		default: {},
+		options: [
+			{
+				displayName: 'Append',
+				name: 'append',
+				type: 'boolean',
+				default: false,
+				description:
+					"Whether to append to an existing file. While it's commonly used with text files, it's not limited to them, however, it wouldn't be applicable for file types that have a specific structure like most binary formats.",
+			},
+		],
+	},
+];
+
+const displayOptions = {
+	show: {
+		operation: ['write'],
+	},
+};
+
+export const description = updateDisplayOptions(displayOptions, properties);
+
+export async function execute(this: IExecuteFunctions, items: INodeExecutionData[]) {
+	const returnData: INodeExecutionData[] = [];
+	let fileName;
+
+	let item: INodeExecutionData;
+	for (let itemIndex = 0; itemIndex < items.length; itemIndex++) {
+		try {
+			const dataPropertyName = this.getNodeParameter('dataPropertyName', itemIndex);
+			fileName = this.getNodeParameter('fileName', itemIndex) as string;
+			const options = this.getNodeParameter('options', itemIndex, {});
+			const flag: string = options.append ? 'a' : 'w';
+
+			item = items[itemIndex];
+
+			const newItem: INodeExecutionData = {
+				json: {},
+				pairedItem: {
+					item: itemIndex,
+				},
+			};
+			Object.assign(newItem.json, item.json);
+
+			const binaryData = this.helpers.assertBinaryData(itemIndex, dataPropertyName);
+
+			let fileContent: Buffer | Readable;
+			if (binaryData.id) {
+				fileContent = await this.helpers.getBinaryStream(binaryData.id);
+			} else {
+				fileContent = Buffer.from(binaryData.data, BINARY_ENCODING);
+			}
+
+			// Write the file to disk
+			await this.helpers.writeContentToFile(fileName, fileContent, flag);
+
+			if (item.binary !== undefined) {
+				// Create a shallow copy of the binary data so that the old
+				// data references which do not get changed still stay behind
+				// but the incoming data does not get changed.
+				newItem.binary = {};
+				Object.assign(newItem.binary, item.binary);
+			}
+
+			// Add the file name to data
+			newItem.json.fileName = fileName;
+
+			returnData.push(newItem);
+		} catch (error) {
+			const nodeOperatioinError = errorMapper.call(this, error, itemIndex, {
+				filePath: fileName,
+				operation: 'write',
+			});
+			if (this.continueOnFail()) {
+				returnData.push({
+					json: {
+						error: nodeOperatioinError.message,
+					},
+					pairedItem: {
+						item: itemIndex,
+					},
+				});
+				continue;
+			}
+			throw nodeOperatioinError;
+		}
+	}
+
+	return returnData;
+}