Get terminal size for bun runtime via tput

src/bun/terminal_io.ts

@@ -3,6 +3,22 @@
  */
 import { ITerminalIO, ITerminalSize } from '../common/mod.ts';
 
+function getSizeFromTput(): ITerminalSize {
+	const rows = parseInt(
+		Bun.spawnSync(['tput', 'lines']).stdout.toString().trim(),
+		10,
+	);
+	const cols = parseInt(
+		Bun.spawnSync(['tput', 'cols']).stdout.toString().trim(),
+		10,
+	);
+
+	return {
+		rows: (rows > 0) ? rows : 25,
+		cols: (cols > 0) ? cols : 80,
+	};
+}
+
 const BunTerminalIO: ITerminalIO = {
 	inputLoop: async function* inputLoop() {
 		for await (const chunk of Bun.stdin.stream()) {
@@ -10,14 +26,7 @@ const BunTerminalIO: ITerminalIO = {
 		}
 	},
 	getSize: function getSize(): ITerminalSize {
-		// @TODO implement
-		// Check for tput
-		// If has tput, use it to get terminal size
-		// If not, try FFI fallback
-		// Otherwise, return 80x25 as a last resort
-		const fallback: ITerminalSize = { rows: 25, cols: 80 };
-
-		return fallback;
+		return getSizeFromTput();
 	},
 	write: async function write(s: string): Promise<void> {
 		const buffer = new TextEncoder().encode(s);

src/common/editor/editor.ts

@@ -2,11 +2,16 @@ import Ansi from './ansi.ts';
 import Buffer from './buffer.ts';
 import { importDefaultForRuntime } from '../runtime.ts';
 import { ctrl_key } from '../strings.ts';
+import { ITerminalSize } from '../types.ts';
 
 export class Editor {
 	#buffer: Buffer;
-	constructor() {
+	#screenRows: number;
+	#screenCols: number;
+	constructor(terminalSize: ITerminalSize) {
 		this.#buffer = new Buffer();
+		this.#screenRows = terminalSize.rows;
+		this.#screenCols = terminalSize.cols;
 	}
 
 	/**
@@ -38,7 +43,7 @@ export class Editor {
 	}
 
 	private drawRows(): void {
-		for (let y = 0; y <= 24; y++) {
+		for (let y = 0; y <= this.#screenRows; y++) {
 			this.#buffer.appendLine('~');
 		}
 	}

src/scroll.ts

@@ -11,7 +11,9 @@ import {
 const decoder = new TextDecoder();
 
 export async function main() {
-	const { inputLoop } = await importDefaultForRuntime('terminal_io.ts');
+	const { inputLoop, getSize } = await importDefaultForRuntime(
+		'terminal_io.ts',
+	);
 	const { onExit } = await importForRuntime('mod.ts');
 
 	// Setup raw mode, and tear down on error or normal exit
@@ -23,7 +25,7 @@ export async function main() {
 	});
 
 	// Create the editor itself
-	const editor = new Editor();
+	const editor = new Editor(getSize());
 
 	// The main event loop
 	for await (const chunk of inputLoop()) {