Add Unicode math output formatting

tests/test_config.py

@@ -13,6 +13,7 @@ def test_load_default_config(tmp_path):
 
     assert cfg.provider == "ollama"
     assert cfg.hotkey == "ctrl+alt+a"
+    assert cfg.math_text_format == "unicode"
     assert "Réponds directement" in cfg.system_prompt
 
 
@@ -25,6 +26,14 @@ def test_timeout_zero_disables_timeout(tmp_path):
     assert cfg.request_timeout_seconds is None
 
 
+def test_reject_invalid_math_text_format(tmp_path):
+    path = tmp_path / "config.json"
+    path.write_text(json.dumps({"provider": "ollama", "math_text_format": "bad"}), encoding="utf-8")
+
+    with pytest.raises(ValueError):
+        load_config(path)
+
+
 def test_reject_invalid_provider(tmp_path):
     path = tmp_path / "config.json"
     path.write_text(json.dumps({"provider": "bad"}), encoding="utf-8")

tests/test_math_format.py

@@ -0,0 +1,24 @@
+import pytest
+
+from ai_typewriter.math_format import format_math_text
+
+
+def test_plain_mode_keeps_linear_math_literal():
+    assert format_math_text("z_1 + x^2", "plain") == "z_1 + x^2"
+
+
+def test_unicode_mode_converts_indices_exponents_and_symbols():
+    result = format_math_text(r"z_1 + x^2 + x_(i+1) + \alpha + \infty", "unicode")
+
+    assert result == "z₁ + x² + xᵢ₊₁ + α + ∞"
+
+
+def test_unicode_mode_converts_common_operators():
+    result = format_math_text(r"\int_0^1 f(x) dx \leq \sum_(k=1)^n a_k", "unicode")
+
+    assert result == "∫₀¹ f(x) dx ≤ ∑ₖ₌₁ⁿ aₖ"
+
+
+def test_invalid_math_text_format_is_rejected():
+    with pytest.raises(ValueError):
+        format_math_text("x_1", "bad")