feat(ppclock): 倒计时前缀文字位图（clock 拆包/calendar 990 序列）+ CLI --prefix/--show-calendar，102 测试全绿

tests/test_textbitmap.py

@@ -0,0 +1,73 @@
+"""倒计时前缀文字位图测试（证据 analysis/web/timedjs2.js:180-236）。"""
+import pytest
+
+from ppclock import textbitmap as TB
+
+
+class TestCharUnits:
+    def test_chinese_counts_one(self):
+        assert TB.char_units("距离") == 2.0
+
+    def test_english_counts_half(self):
+        assert TB.char_units("ab") == 1.0
+        assert TB.char_units("ab中") == 2.0
+        assert TB.char_units("a中") == 1.5
+
+
+class TestBitmap:
+    def test_clock_bitmap_size(self):
+        """16px 格：n 个单位 → n*32 字节"""
+        bmp = TB.render_text_bitmap("中考", grid=16)
+        assert len(bmp) == 2 * 32
+
+    def test_calendar_bitmap_size(self):
+        """24px 格：n 个单位 → n*72 字节"""
+        bmp = TB.render_text_bitmap("中考", grid=24)
+        assert len(bmp) == 2 * 72
+
+    def test_bitmap_not_blank(self):
+        bmp = TB.render_text_bitmap("试", grid=16)
+        assert any(bmp)
+
+    def test_grid_must_be_16_or_24(self):
+        with pytest.raises(ValueError):
+            TB.render_text_bitmap("x", grid=12)
+
+
+class TestFrames:
+    def test_clock_single_pack(self):
+        """≤4 单位：单包 0{n}+位图"""
+        frames = TB.prefix_frames("目标", "clock")
+        assert len(frames) == 1
+        assert frames[0][0:1] == bytes([0x02])  # '0'+2
+        assert len(frames[0]) == 1 + 2 * 32
+
+    def test_clock_two_packs(self):
+        """>4 单位：首包 04+128B，次包 0{n}+余量"""
+        frames = TB.prefix_frames("距离中考还有", "clock")  # 6 单位
+        assert len(frames) == 2
+        assert frames[0][0] == 0x04
+        assert len(frames[0]) == 1 + 128
+        assert frames[1][0] == 0x06
+        assert len(frames[1]) == 1 + 2 * 32
+
+    def test_clock_over_8_units_rejected(self):
+        with pytest.raises(ValueError):
+            TB.prefix_frames("一二三四五六七八九", "clock")
+
+    def test_calendar_per_char_pack(self):
+        """日历模式：每字一包 990{j}+72B"""
+        frames = TB.prefix_frames("中考", "calendar")
+        assert len(frames) == 2
+        assert frames[0][:2] == bytes([0x99, 0x00])
+        assert len(frames[0]) == 2 + 72
+        assert frames[1][:2] == bytes([0x99, 0x01])
+
+    def test_calendar_over_4_units_rejected(self):
+        with pytest.raises(ValueError):
+            TB.prefix_frames("一二三四五", "calendar")
+
+    def test_fractional_units_rejected(self):
+        """0.5 单位（英文混排）JS 会产生非法 hex——CLI 拒绝"""
+        with pytest.raises(ValueError):
+            TB.prefix_frames("a中", "clock")