test: strengthen assertions after review

- Use deepEqual for shape verification on first two measureText tests
- Add value assertions to cache test before identity check
- Add 256-color ANSI escape sequence test
- Add lines.length assertions in multiline text-width tests
- Remove redundant single-character test and restating comments

Author: costajohnt

test/measure-text.tsx

@@ -2,21 +2,11 @@ import test from 'ava';
 import measureText from '../src/measure-text.js';
 
 test('measure single word', t => {
-	const result = measureText('constructor');
-	t.is(result.width, 11);
-	t.is(result.height, 1);
+	t.deepEqual(measureText('constructor'), {width: 11, height: 1});
 });
 
 test('measure empty string', t => {
-	const result = measureText('');
-	t.is(result.width, 0);
-	t.is(result.height, 0);
-});
-
-test('measure single character', t => {
-	const result = measureText('x');
-	t.is(result.width, 1);
-	t.is(result.height, 1);
+	t.deepEqual(measureText(''), {width: 0, height: 0});
 });
 
 test('measure multiline text', t => {
@@ -45,19 +35,25 @@ test('measure text with only newlines', t => {
 
 test('returns cached result on repeated calls', t => {
 	const first = measureText('cached-test');
+	t.is(first.width, 11);
+	t.is(first.height, 1);
 	const second = measureText('cached-test');
 	t.is(first, second);
 });
 
 test('measure text with ANSI escape sequences', t => {
-	// ANSI codes should not count toward width
 	const result = measureText('\u001B[31mred\u001B[0m');
 	t.is(result.width, 3);
 	t.is(result.height, 1);
 });
 
+test('measure text with 256-color ANSI', t => {
+	const result = measureText('\u001B[38;5;196mred\u001B[0m');
+	t.is(result.width, 3);
+	t.is(result.height, 1);
+});
+
 test('measure text with wide characters', t => {
-	// CJK characters are 2 columns wide
 	const result = measureText('你好');
 	t.is(result.width, 4);
 	t.is(result.height, 1);

test/text-width.tsx

@@ -23,7 +23,7 @@ test('wide characters do not add extra space inside fixed-width Box', t => {
 	);
 
 	const lines = output.split('\n');
-	// Both lines should have the pipe directly after the 2-column box
+	t.is(lines.length, 2);
 	t.is(lines[0], '🍔|');
 	t.is(lines[1], '⏳|');
 });
@@ -60,6 +60,7 @@ test('mixed ASCII and wide characters align correctly', t => {
 	);
 
 	const lines = output.split('\n');
+	t.is(lines.length, 2);
 	t.is(lines[0], 'ab🍔cd|');
 	t.is(lines[1], 'abcdef|');
 });