Fixes with tests

extensions/ipynb/src/serializers.ts

@@ -227,7 +227,7 @@ function convertStreamOutput(output: NotebookCellOutput): JupyterOutput {
 	const outputs: string[] = [];
 	output.items
 		.filter((opit) => opit.mime === CellOutputMimeTypes.stderr || opit.mime === CellOutputMimeTypes.stdout)
-		.map((opit) => convertOutputMimeToJupyterOutput(opit.mime, opit.data as Uint8Array) as string)
+		.map((opit) => textDecoder.decode(opit.data))
 		.forEach(value => {
 			// Ensure each line is a seprate entry in an array (ending with \n).
 			const lines = value.split('\n');
@@ -240,6 +240,11 @@ function convertStreamOutput(output: NotebookCellOutput): JupyterOutput {
 				outputs.push(line);
 			}
 		});
+
+	for (let index = 0; index < (outputs.length - 1); index++) {
+		outputs[index] = `${outputs[index]}\n`;
+	}
+
 	// Skip last one if empty (it's the only one that could be length 0)
 	if (outputs.length && outputs[outputs.length - 1].length === 0) {
 		outputs.pop();

extensions/ipynb/src/test/serializers.test.ts

@@ -106,6 +106,48 @@ suite('ipynb serializer', () => {
 				]
 			);
 		});
+		test('Stream output and line endings', () => {
+			validateCellOutputTranslation(
+				[
+					{
+						output_type: 'stream',
+						name: 'stdout',
+						text: [
+							'Line1\n',
+							'\n',
+							'Line3\n',
+							'Line4'
+						]
+					}
+				],
+				[
+					new vscode.NotebookCellOutput([vscode.NotebookCellOutputItem.stdout('Line1\n\nLine3\nLine4')], {
+						outputType: 'stream'
+					})
+				]
+			);
+			validateCellOutputTranslation(
+				[
+					{
+						output_type: 'stream',
+						name: 'stdout',
+						text: [
+							'Hello\n',
+							'Hello\n',
+							'Hello\n',
+							'Hello\n',
+							'Hello\n',
+							'Hello\n'
+						]
+					}
+				],
+				[
+					new vscode.NotebookCellOutput([vscode.NotebookCellOutputItem.stdout('Hello\nHello\nHello\nHello\nHello\nHello\n')], {
+						outputType: 'stream'
+					})
+				]
+			);
+		});
 		test('Multi-line Stream output', () => {
 			validateCellOutputTranslation(
 				[