Add snapshot tests for indentation

extensions/positron-r/src/test/editor-utils.ts

@@ -6,7 +6,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import * as assert from 'assert';
 import * as fs from 'fs';
 import * as os from 'os';
 import { join } from 'path';
@@ -44,36 +43,40 @@ export function deleteFile(file: vscode.Uri): Thenable<boolean> {
 			}
 		});
 	});
-} export const CURSOR = '$$CURSOR$$';
+}
+
+export const CURSOR = '"<>"';
 
-export function withRandomFileEditor(
+export async function withFileEditor(
 	contents: string,
 	fileExtension: string,
-	run: (editor: vscode.TextEditor, doc: vscode.TextDocument) => Thenable<void>
-): Thenable<boolean> {
+	run: (editor: vscode.TextEditor, doc: vscode.TextDocument) => Promise<void>
+): Promise<void> {
 	const cursorIndex = contents.indexOf(CURSOR);
-	return createRandomFile(contents.replace(CURSOR, ''), fileExtension).then(file => {
-		return vscode.workspace.openTextDocument(file).then(doc => {
-			return vscode.window.showTextDocument(doc).then((editor) => {
-				if (cursorIndex >= 0) {
-					const pos = doc.positionAt(cursorIndex);
-					editor.selection = new vscode.Selection(pos, pos);
-				}
-				return run(editor, doc).then(_ => {
-					if (doc.isDirty) {
-						return doc.save().then(() => {
-							return deleteFile(file);
-						});
-					} else {
-						return deleteFile(file);
-					}
-				});
-			});
-		});
-	});
+	const rawContents = contents.replace(CURSOR, '');
+
+	const file = await createRandomFile(rawContents, fileExtension);
+
+	try {
+		const doc = await vscode.workspace.openTextDocument(file);
+		const editor = await vscode.window.showTextDocument(doc);
+
+		if (cursorIndex >= 0) {
+			const pos = doc.positionAt(cursorIndex);
+			editor.selection = new vscode.Selection(pos, pos);
+		}
+
+		await run(editor, doc);
+
+		if (doc.isDirty) {
+			await doc.save();
+		}
+	} finally {
+		deleteFile(file);
+	}
 }
 
-const onDocumentChange = (doc: vscode.TextDocument): Promise<vscode.TextDocument> => {
+export const onDocumentChange = (doc: vscode.TextDocument): Promise<vscode.TextDocument> => {
 	return new Promise<vscode.TextDocument>(resolve => {
 		const sub = vscode.workspace.onDidChangeTextDocument(e => {
 			if (e.document !== doc) {

extensions/positron-r/src/test/indentation.test.ts

@@ -1,11 +1,62 @@
+import * as vscode from 'vscode';
 import * as assert from 'assert';
-import { withRandomFileEditor, CURSOR, type } from './editor-utils';
+import * as fs from 'fs';
+import { CURSOR, type, withFileEditor } from './editor-utils';
+
+const snapshotsFolder = `${__dirname}/../../src/test/snapshots`;
+const snippetsPath = `${snapshotsFolder}/indentation-cases.R`;
+const snapshotsPath = `${snapshotsFolder}/indentation-snapshots.R`;
+
+// FIXME: This should normally be run as part of tests setup in `before()` but
+// it's somehow not defined
+async function init() {
+	// Open workspace with custom configuration for snapshots. If you need
+	// custom settings set them there via `config.update()`.
+	const uri = vscode.Uri.file(snapshotsFolder);
+	await vscode.commands.executeCommand('vscode.openFolder', uri, false);
+	const config = vscode.workspace.getConfiguration();
+
+	// Prevents `ENOENT: no such file or directory` errors caused by us
+	// deleting temporary editor files befor Code had the opportunity to
+	// save the user history of these files (see )
+	config.update('workbench.localHistory.enabled', false, vscode.ConfigurationTarget.Workspace);
+}
 
 suite('Indentation', () => {
-	test('test', async () => {
-		return withRandomFileEditor(`1 +${CURSOR}`, 'R', async (_editor, document) => {
-			await type(document, '\n2');
-			assert.strictEqual(document.getText(), '1 +\n  2');
-		});
+	// This regenerates snapshots in place. If the snapshots differ from last
+	// run, a failure is emitted. You can either commit the new output or discard
+	// it if that's a bug to fix.
+	test('Regenerate and check', async () => {
+		await init();
+		const expected = fs.readFileSync(snapshotsPath, 'utf8');
+		const current = await regenerateIndentSnapshots();
+
+		// Update snapshot file
+		fs.writeFileSync(snapshotsPath, current, 'utf8');
+
+		// Notify if snapshots were outdated
+		assert.strictEqual(expected, current);
+		console.log('dirname: ', __dirname);
 	});
 });
+
+async function regenerateIndentSnapshots() {
+	const snippets = fs.
+		readFileSync(snippetsPath, 'utf8').
+		split('# ---\n');
+
+	// Remove documentation snippet
+	snippets.splice(0, 1);
+
+	const snapshots: string[] = ['# File generated from `indentation-cases.R`.\n\n'];
+
+	for (const snippet of snippets) {
+		await withFileEditor(snippet, 'R', async (_editor, doc) => {
+			// Type one newline character to trigger indentation
+			await type(doc, `\n${CURSOR}`);
+			snapshots.push(doc.getText());
+		});
+	}
+
+	return snapshots.join('# --- \n');
+}

extensions/positron-r/src/test/snapshots/.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "workbench.localHistory.enabled": false
+}

extensions/positron-r/src/test/snapshots/indentation-cases.R

@@ -0,0 +1,82 @@
+# Indentation snapshots. Edit cases in `indentation-cases.R` and observe results
+# in `indentation-snapshots.R`.
+#
+# The cursor position is represented by a string containing angular brackets. A
+# newline is typed at that position, triggering indentation rules. The result is
+# saved in the snapshot file.
+#
+# Snippets are separated by `# ---`. This makes it possible to extract them and
+# process them separately to prevent interferences between test cases.
+
+# ---
+1 +"<>"
+
+# ---
+1 +
+	2 +"<>"
+
+# ---
+data |>"<>"
+
+# ---
+data |>
+	fn()"<>"
+
+# ---
+# https://github.com/posit-dev/positron/issues/1727
+# FIXME
+data |>
+	fn()
+"<>"
+
+# ---
+# https://github.com/posit-dev/positron/issues/1316
+data |>
+	fn() |>"<>"
+
+# ---
+# With trailing whitespace
+# https://github.com/posit-dev/positron/pull/1655#issuecomment-1780093395
+data |>
+	fn() |> "<>"
+
+# ---
+data |>
+	fn1() |>
+	fn2() |>"<>"
+
+# ---
+# FIXME
+data |>
+	fn1() |>
+	fn2(
+    "arg"
+  )"<>"
+
+# ---
+# https://github.com/posit-dev/positron-beta/discussions/46
+# FIXME
+data |>
+	fn("<>")
+
+# ---
+# FIXME
+{
+	fn(function() {}"<>")
+}
+
+# ---
+# FIXME
+{
+	fn(function() {
+    #
+	}"<>")
+}
+
+# ---
+for (i in NA) NULL"<>"
+
+# ---
+# https://github.com/posit-dev/positron/issues/1880
+# FIXME
+for (i in 1) fn()"<>"

extensions/positron-r/src/test/snapshots/indentation-snapshots.R

@@ -0,0 +1,88 @@
+# File generated from `indentation-cases.R`.
+
+# --- 
+1 +
+  "<>"
+
+# --- 
+1 +
+	2 +
+	"<>"
+
+# --- 
+data |>
+  "<>"
+
+# --- 
+data |>
+	fn()
+"<>"
+
+# --- 
+# https://github.com/posit-dev/positron/issues/1727
+# FIXME
+data |>
+	fn()
+
+	"<>"
+
+# --- 
+# https://github.com/posit-dev/positron/issues/1316
+data |>
+	fn() |>
+	"<>"
+
+# --- 
+# With trailing whitespace
+# https://github.com/posit-dev/positron/pull/1655#issuecomment-1780093395
+data |>
+	fn() |> 
+	"<>"
+
+# --- 
+data |>
+	fn1() |>
+	fn2() |>
+	"<>"
+
+# --- 
+# FIXME
+data |>
+	fn1() |>
+	fn2(
+    "arg"
+  )
+  "<>"
+
+# --- 
+# https://github.com/posit-dev/positron-beta/discussions/46
+# FIXME
+data |>
+	fn(
+"<>")
+
+# --- 
+# FIXME
+{
+	fn(function() {}
+"<>")
+}
+
+# --- 
+# FIXME
+{
+	fn(function() {
+    #
+	}
+"<>")
+}
+
+# --- 
+for (i in NA) NULL
+"<>"
+
+# --- 
+# https://github.com/posit-dev/positron/issues/1880
+# FIXME
+for (i in 1) fn()
+  "<>"