bug fixes, and performance improvements, and drawer

tests/composer-size.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, test } from 'bun:test';
+import { getComposerHeight } from '../app/utils/composer-size';
+
+describe('composer height stability', () => {
+    test('subpixel noise never oscillates around the two-line minimum', () => {
+        const heights = [47.99999, 48, 48.01].map(height => getComposerHeight(height, 24, 0, 0, true));
+        expect(heights).toEqual([48, 48, 48]);
+    });
+
+    test('grows and shrinks for actual lines, capped at ten lines', () => {
+        expect([24, 48, 72, 264, 72, 24].map(height => getComposerHeight(height, 24, 0, 0, true)))
+            .toEqual([48, 48, 72, 240, 72, 48]);
+    });
+
+    test('accounts for padding and borders according to box sizing', () => {
+        expect(getComposerHeight(80, 24, 8, 2, true)).toBe(82);
+        expect(getComposerHeight(80, 24, 8, 2, false)).toBe(72);
+        expect(getComposerHeight(10, 24, 8, 2, true)).toBe(58);
+    });
+
+    test('respects fractional typography rather than hardcoding a 24px line', () => {
+        expect(getComposerHeight(40, 20.25, 0, 0, true)).toBe(41);
+        expect(getComposerHeight(1000, 20.25, 0, 0, true)).toBe(203);
+    });
+});