Implement onDidChangeTerminalDimensions

Fixes #55718

extensions/vscode-api-tests/src/singlefolder-tests/window.test.ts

@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as assert from 'assert';
-import { workspace, window, commands, ViewColumn, TextEditorViewColumnChangeEvent, Uri, Selection, Position, CancellationTokenSource, TextEditorSelectionChangeKind, Terminal } from 'vscode';
+import { workspace, window, commands, ViewColumn, TextEditorViewColumnChangeEvent, Uri, Selection, Position, CancellationTokenSource, TextEditorSelectionChangeKind, Terminal, TerminalDimensionsChangeEvent } from 'vscode';
 import { join } from 'path';
 import { closeAllEditors, pathEquals, createRandomFile } from '../utils';
 
@@ -695,6 +695,45 @@ suite('window namespace tests', () => {
 			const terminal = window.createTerminal();
 			terminal.show();
 		});
+
+		test('onDidChangeTerminalDimensions should fire when new terminals are created', (done) => {
+			const reg1 = window.onDidChangeTerminalDimensions((event: TerminalDimensionsChangeEvent) => {
+				assert.equal(event.terminal, terminal1);
+				assert.equal(typeof event.dimensions.columns, 'number');
+				assert.equal(typeof event.dimensions.rows, 'number');
+				assert.ok(event.dimensions.columns > 0);
+				assert.ok(event.dimensions.rows > 0);
+				reg1.dispose();
+				let terminal2: Terminal;
+				const reg2 = window.onDidOpenTerminal((newTerminal) => {
+					// THis is guarentees to fire before dimensions change event
+					if (newTerminal !== terminal1) {
+						terminal2 = newTerminal;
+						reg2.dispose();
+					}
+				});
+				let firstCalled = false;
+				let secondCalled = false;
+				const reg3 = window.onDidChangeTerminalDimensions((event: TerminalDimensionsChangeEvent) => {
+					if (event.terminal === terminal1) {
+						// The original terminal should fire dimension change after a split
+						firstCalled = true;
+					} else if (event.terminal !== terminal1) {
+						// The new split terminal should fire dimension change
+						secondCalled = true;
+					}
+					if (firstCalled && secondCalled) {
+						terminal1.dispose();
+						terminal2.dispose();
+						reg3.dispose();
+						done();
+					}
+				});
+				commands.executeCommand('workbench.action.terminal.split');
+			});
+			const terminal1 = window.createTerminal({ name: 'test' });
+			terminal1.show();
+		});
 	});
 });