test(theme): 为系统主题检测相关函数添加详细单元测试

- 添加 parseOscRgb 函数各种格式输入的测试用例，包括 rgb、rgba、短十六进制和无效输入
- 测试 themeFromOscColor 函数对于不同背景颜色的亮暗主题判断
- 验证 detectFromColorFgBg 函数对环境变量 COLORFGBG 不同值的正确处理
- 编写 detectSystemTheme 函数的主题检测结果有效性及优先级测试
- 覆盖异常及边界情况，确保函数在无环境变量或无效输入时表现稳定

Author: hqwlkj

src/tests/detect-system-theme.test.ts

@@ -0,0 +1,318 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import {
+  parseOscRgb,
+  themeFromOscColor,
+  detectFromColorFgBg,
+  detectSystemTheme,
+} from "../ui/theme/detect-system-theme";
+
+// ---------------------------------------------------------------------------
+// parseOscRgb
+// ---------------------------------------------------------------------------
+
+test("parseOscRgb parses rgb:RR/GG/BB format", () => {
+  const result = parseOscRgb("rgb:0000/0000/0000");
+  assert.ok(result);
+  assert.equal(result.r, 0);
+  assert.equal(result.g, 0);
+  assert.equal(result.b, 0);
+});
+
+test("parseOscRgb parses rgb:RRRR/GGGG/BBBB format (bright white)", () => {
+  const result = parseOscRgb("rgb:ffff/ffff/ffff");
+  assert.ok(result);
+  assert.equal(result.r, 1);
+  assert.equal(result.g, 1);
+  assert.equal(result.b, 1);
+});
+
+test("parseOscRgb parses rgb:RR/GG/BB with mid values", () => {
+  const result = parseOscRgb("rgb:8080/8080/8080");
+  assert.ok(result);
+  assert.ok(Math.abs(result.r - 0.50196) < 0.001);
+  assert.ok(Math.abs(result.g - 0.50196) < 0.001);
+  assert.ok(Math.abs(result.b - 0.50196) < 0.001);
+});
+
+test("parseOscRgb parses rgb with short hex (1 digit per component)", () => {
+  const result = parseOscRgb("rgb:f/f/f");
+  assert.ok(result);
+  assert.equal(result.r, 1);
+  assert.equal(result.g, 1);
+  assert.equal(result.b, 1);
+});
+
+test("parseOscRgb parses rgb with 2-digit hex", () => {
+  const result = parseOscRgb("rgb:ff/80/00");
+  assert.ok(result);
+  assert.equal(result.r, 1);
+  assert.ok(Math.abs(result.g - 0.50196) < 0.001);
+  assert.equal(result.b, 0);
+});
+
+test("parseOscRgb parses rgba format", () => {
+  const result = parseOscRgb("rgba:ffff/ffff/ffff/ffff");
+  assert.ok(result);
+  assert.equal(result.r, 1);
+  assert.equal(result.g, 1);
+  assert.equal(result.b, 1);
+});
+
+test("parseOscRgb parses #RRGGBB format", () => {
+  const result = parseOscRgb("#000000");
+  assert.ok(result);
+  assert.equal(result.r, 0);
+  assert.equal(result.g, 0);
+  assert.equal(result.b, 0);
+});
+
+test("parseOscRgb parses #RRGGBB format (white)", () => {
+  const result = parseOscRgb("#ffffff");
+  assert.ok(result);
+  assert.equal(result.r, 1);
+  assert.equal(result.g, 1);
+  assert.equal(result.b, 1);
+});
+
+test("parseOscRgb parses #RRRRGGGGBBBB format", () => {
+  const result = parseOscRgb("#ffff80800000");
+  assert.ok(result);
+  assert.equal(result.r, 1);
+  assert.ok(Math.abs(result.g - 0.50196) < 0.001);
+  assert.equal(result.b, 0);
+});
+
+test("parseOscRgb returns undefined for invalid format", () => {
+  assert.equal(parseOscRgb("invalid"), undefined);
+  assert.equal(parseOscRgb(""), undefined);
+  assert.equal(parseOscRgb("rgb:zz/zz/zz"), undefined);
+  assert.equal(parseOscRgb("#gggggg"), undefined);
+});
+
+test("parseOscRgb returns undefined for #RRGGBB with non-multiple-of-3 length", () => {
+  assert.equal(parseOscRgb("#ffff"), undefined);
+  assert.equal(parseOscRgb("#fffff"), undefined);
+});
+
+test("parseOscRgb is case-insensitive", () => {
+  const lower = parseOscRgb("rgb:ffff/0000/8080");
+  const upper = parseOscRgb("RGB:FFFF/0000/8080");
+  assert.ok(lower);
+  assert.ok(upper);
+  assert.equal(lower.r, upper.r);
+  assert.equal(lower.g, upper.g);
+  assert.equal(lower.b, upper.b);
+});
+
+// ---------------------------------------------------------------------------
+// themeFromOscColor
+// ---------------------------------------------------------------------------
+
+test("themeFromOscColor returns 'light' for white background", () => {
+  assert.equal(themeFromOscColor("rgb:ffff/ffff/ffff"), "light");
+  assert.equal(themeFromOscColor("#ffffff"), "light");
+});
+
+test("themeFromOscColor returns 'dark' for black background", () => {
+  assert.equal(themeFromOscColor("rgb:0000/0000/0000"), "dark");
+  assert.equal(themeFromOscColor("#000000"), "dark");
+});
+
+test("themeFromOscColor returns 'light' for bright background", () => {
+  // Luminance of #c0c0c0 (silver) ≈ 0.53 > 0.5
+  assert.equal(themeFromOscColor("#c0c0c0"), "light");
+});
+
+test("themeFromOscColor returns 'dark' for dim background", () => {
+  // Luminance of #404040 ≈ 0.04 < 0.5
+  assert.equal(themeFromOscColor("#404040"), "dark");
+});
+
+test("themeFromOscColor uses ITU-R BT.709 luminance weights", () => {
+  // Pure green has highest luminance weight (0.7152)
+  // rgb:0000/8080/0000 → luminance ≈ 0.7152 * 0.5 ≈ 0.358 → dark
+  assert.equal(themeFromOscColor("rgb:0000/8080/0000"), "dark");
+
+  // Pure green bright → luminance > 0.5 → light
+  assert.equal(themeFromOscColor("rgb:0000/ffff/0000"), "light");
+
+  // Pure blue has lowest weight (0.0722)
+  // rgb:0000/0000/ffff → luminance ≈ 0.0722 → dark
+  assert.equal(themeFromOscColor("rgb:0000/0000/ffff"), "dark");
+});
+
+test("themeFromOscColor returns undefined for invalid input", () => {
+  assert.equal(themeFromOscColor("invalid"), undefined);
+  assert.equal(themeFromOscColor(""), undefined);
+});
+
+// ---------------------------------------------------------------------------
+// detectFromColorFgBg
+// ---------------------------------------------------------------------------
+
+test("detectFromColorFgBg returns 'dark' for dark background indices", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    // Index 0 = black
+    process.env["COLORFGBG"] = "15;0";
+    assert.equal(detectFromColorFgBg(), "dark");
+
+    // Index 1 = red
+    process.env["COLORFGBG"] = "15;1";
+    assert.equal(detectFromColorFgBg(), "dark");
+
+    // Index 6 = cyan
+    process.env["COLORFGBG"] = "15;6";
+    assert.equal(detectFromColorFgBg(), "dark");
+
+    // Index 8 = bright black (dark gray)
+    process.env["COLORFGBG"] = "15;8";
+    assert.equal(detectFromColorFgBg(), "dark");
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectFromColorFgBg returns 'light' for light background indices", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    // Index 7 = light gray
+    process.env["COLORFGBG"] = "0;7";
+    assert.equal(detectFromColorFgBg(), "light");
+
+    // Index 9 = bright red
+    process.env["COLORFGBG"] = "0;9";
+    assert.equal(detectFromColorFgBg(), "light");
+
+    // Index 15 = bright white
+    process.env["COLORFGBG"] = "0;15";
+    assert.equal(detectFromColorFgBg(), "light");
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectFromColorFgBg handles foreground;background format", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    // Only the last segment (background) matters
+    process.env["COLORFGBG"] = "0;15";
+    assert.equal(detectFromColorFgBg(), "light");
+
+    process.env["COLORFGBG"] = "15;0";
+    assert.equal(detectFromColorFgBg(), "dark");
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectFromColorFgBg handles single value (background only)", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    process.env["COLORFGBG"] = "0";
+    assert.equal(detectFromColorFgBg(), "dark");
+
+    process.env["COLORFGBG"] = "15";
+    assert.equal(detectFromColorFgBg(), "light");
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectFromColorFgBg returns undefined when COLORFGBG is not set", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    delete process.env["COLORFGBG"];
+    assert.equal(detectFromColorFgBg(), undefined);
+  } finally {
+    if (original !== undefined) {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectFromColorFgBg returns undefined for non-numeric value", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    process.env["COLORFGBG"] = "abc";
+    assert.equal(detectFromColorFgBg(), undefined);
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectFromColorFgBg returns undefined for empty string", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    process.env["COLORFGBG"] = "";
+    assert.equal(detectFromColorFgBg(), undefined);
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+// ---------------------------------------------------------------------------
+// detectSystemTheme (sync entry point)
+// ---------------------------------------------------------------------------
+
+test("detectSystemTheme returns a valid theme", () => {
+  const result = detectSystemTheme();
+  assert.ok(result === "light" || result === "dark");
+});
+
+test("detectSystemTheme prefers COLORFGBG over other sources", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    process.env["COLORFGBG"] = "0;15"; // light background
+    assert.equal(detectSystemTheme(), "light");
+
+    process.env["COLORFGBG"] = "15;0"; // dark background
+    assert.equal(detectSystemTheme(), "dark");
+  } finally {
+    if (original === undefined) {
+      delete process.env["COLORFGBG"];
+    } else {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});
+
+test("detectSystemTheme falls back to 'dark' when no sources available", () => {
+  const original = process.env["COLORFGBG"];
+  try {
+    delete process.env["COLORFGBG"];
+    // On non-macOS, detectMacOSTheme returns undefined → falls back to "dark"
+    // On macOS, it depends on system settings
+    const result = detectSystemTheme();
+    assert.ok(result === "light" || result === "dark");
+  } finally {
+    if (original !== undefined) {
+      process.env["COLORFGBG"] = original;
+    }
+  }
+});