[Init] Initial commit - NetMesh terminal manager

domain/cursorLineHighlight.test.ts

@@ -0,0 +1,85 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+
+import {
+  CURSOR_LINE_HIGHLIGHT_BLEND,
+  ensureCursorLineHighlightContrast,
+  resolveCursorLineHighlightBackground,
+} from './cursorLineHighlight.ts';
+
+test('resolveCursorLineHighlightBackground mixes the selection with the theme background', () => {
+  const color = resolveCursorLineHighlightBackground({
+    background: '#0d1117',
+    foreground: '#c9d1d9',
+    selection: '#264f78',
+  });
+  assert.equal(color, '#1b334c');
+});
+
+test('resolveCursorLineHighlightBackground falls back to foreground when selection is invalid', () => {
+  const withSelection = resolveCursorLineHighlightBackground({
+    background: '#000000',
+    foreground: '#ffffff',
+    selection: '#808080',
+  });
+  const withoutSelection = resolveCursorLineHighlightBackground({
+    background: '#000000',
+    foreground: '#ffffff',
+    selection: 'not-a-color',
+  });
+  assert.equal(withSelection, '#464646');
+  assert.equal(withoutSelection, '#707070');
+});
+
+test('resolveCursorLineHighlightBackground expands short hex and strips alpha', () => {
+  const short = resolveCursorLineHighlightBackground({
+    background: '#000',
+    foreground: '#fff',
+    selection: '#88888888',
+  });
+  assert.equal(short, '#4b4b4b');
+});
+
+test('CURSOR_LINE_HIGHLIGHT_BLEND stays a visible fraction', () => {
+  assert.ok(CURSOR_LINE_HIGHLIGHT_BLEND > 0 && CURSOR_LINE_HIGHLIGHT_BLEND < 1);
+});
+
+test('resolveCursorLineHighlightBackground keeps white text readable', () => {
+  const color = resolveCursorLineHighlightBackground({
+    background: '#0d1117',
+    foreground: '#ffffff',
+    selection: '#ffffff',
+  });
+  const channel = Number.parseInt(color.slice(1, 3), 16) / 255;
+  const luminance = channel <= 0.03928 ? channel / 12.92 : ((channel + 0.055) / 1.055) ** 2.4;
+  assert.ok((1.05) / (luminance + 0.05) >= 4.5);
+});
+
+test('resolveCursorLineHighlightBackground repairs a low-contrast light theme', () => {
+  assert.equal(
+    resolveCursorLineHighlightBackground({
+      background: '#f0f0f0',
+      foreground: '#888888',
+      selection: '#ffffff',
+    }),
+    '#000000',
+  );
+});
+
+test('ensureCursorLineHighlightContrast protects keyword blue', () => {
+  assert.equal(
+    ensureCursorLineHighlightContrast('#1b334c', ['#3b82f6']),
+    '#000000',
+  );
+});
+
+test('resolveCursorLineHighlightBackground keeps Tokyo Night Light visible', () => {
+  assert.notEqual(
+    resolveCursorLineHighlightBackground({
+      background: '#e1e2e7',
+      foreground: '#3760bf',
+      selection: '#abc7d4',
+    }),
+    '#e1e2e7',
+  );
+});