test(interactive_preview): add unit tests for interactive preview helpers

Author: ttw225

tests/test_interactive_preview.py

@@ -0,0 +1,124 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from commitizen import interactive_preview
+
+if TYPE_CHECKING:
+    import pytest
+
+
+def test_wrap_display_width_empty_and_non_positive_width():
+    assert interactive_preview._wrap_display_width("", 10) == []
+    assert interactive_preview._wrap_display_width("abc", 0) == ["abc"]
+    assert interactive_preview._wrap_display_width("abc", -1) == ["abc"]
+
+
+def test_wrap_display_width_ascii_simple_wrap(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setattr(interactive_preview, "get_cwidth", lambda _c: 1)
+    assert interactive_preview._wrap_display_width("abcd", 2) == ["ab", "cd"]
+    assert interactive_preview._wrap_display_width("abc", 2) == ["ab", "c"]
+
+
+def test_wrap_display_width_cjk_width_2(monkeypatch: pytest.MonkeyPatch):
+    def fake_cwidth(c: str) -> int:
+        return 2 if c == "你" else 1
+
+    monkeypatch.setattr(interactive_preview, "get_cwidth", fake_cwidth)
+    assert interactive_preview._wrap_display_width("你a", 2) == ["你", "a"]
+
+
+def test_make_toolbar_content_includes_preview_and_counter_with_max(
+    monkeypatch: pytest.MonkeyPatch,
+    mocker,
+):
+    def subject_builder(_field: str, _text: str) -> str:
+        return "feat: abc"
+
+    monkeypatch.setattr(
+        interactive_preview,
+        "get_terminal_size",
+        lambda: mocker.Mock(columns=20),
+    )
+
+    content = interactive_preview.make_toolbar_content(
+        subject_builder, "subject", "abc", max_length=50
+    )
+    preview, counter = content.splitlines()
+    assert preview == "feat: abc"
+    assert counter.strip() == "9/50 chars"
+
+
+def test_make_toolbar_content_counter_without_max_when_zero(
+    monkeypatch: pytest.MonkeyPatch,
+    mocker,
+):
+    def subject_builder(_field: str, _text: str) -> str:
+        return "fix: a"
+
+    monkeypatch.setattr(
+        interactive_preview,
+        "get_terminal_size",
+        lambda: mocker.Mock(columns=80),
+    )
+    content = interactive_preview.make_toolbar_content(
+        subject_builder, "subject", "a", max_length=0
+    )
+    assert content.splitlines()[-1].strip() == "6 chars"
+
+
+def test_make_toolbar_content_terminal_size_oserror_fallback_80(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    def subject_builder(_field: str, _text: str) -> str:
+        return "feat: abc"
+
+    def raise_oserror():
+        raise OSError("no tty")
+
+    monkeypatch.setattr(interactive_preview, "get_terminal_size", raise_oserror)
+
+    content = interactive_preview.make_toolbar_content(
+        subject_builder, "subject", "abc", max_length=50
+    )
+    assert content.splitlines()[-1].startswith(" " * (80 - len("9/50 chars")))
+
+
+def test_make_toolbar_content_counter_padding_not_negative(
+    monkeypatch: pytest.MonkeyPatch,
+    mocker,
+):
+    def subject_builder(_field: str, _text: str) -> str:
+        return "x"
+
+    # Make width tiny so counter is longer than width
+    monkeypatch.setattr(
+        interactive_preview,
+        "get_terminal_size",
+        lambda: mocker.Mock(columns=3),
+    )
+    content = interactive_preview.make_toolbar_content(
+        subject_builder, "subject", "x", max_length=50
+    )
+    assert content.splitlines()[-1] == "1/50 chars"
+
+
+def test_make_length_validator_disabled_when_max_length_zero():
+    def subject_builder(_field: str, text: str) -> str:
+        return text
+
+    validate = interactive_preview.make_length_validator(
+        subject_builder, "subject", max_length=0
+    )
+    assert validate("x" * 10) is True
+
+
+def test_make_length_validator_returns_error_string_when_exceeded():
+    def subject_builder(_field: str, text: str) -> str:
+        return text
+
+    validate = interactive_preview.make_length_validator(
+        subject_builder, "subject", max_length=3
+    )
+    assert validate("abc") is True
+    assert validate("abcd") == "4/3 chars (subject length exceeded)"