Implement census analysis: read, count, summarise, write and CLI

Closes #11 Closes #12 Closes #13 Closes #14 Closes #15 Task: MIL-002#4 Task: MIL-002#5 Task: MIL-002#6 Task: MIL-002#7 Task: MIL-002#8
2026-10-13 15:37:51 +08:00
parent 259d017ad2
commit 7459711243
9 changed files with 364 additions and 0 deletions
@@ -0,0 +1,67 @@
+"""Tests for the squirrel.cli module."""
+
+import pathlib
+
+import pytest
+
+from squirrel import cli
+from squirrel.constants import (
+    FILE_ENCODING,
+    FUR_COLOR_COLUMN,
+    FUR_COLORS,
+    SUMMARY_COLUMNS,
+)
+
+
+def _write_census(path: pathlib.Path) -> None:
+    gray, cinnamon, _black = FUR_COLORS
+    lines = [FUR_COLOR_COLUMN, gray, gray, cinnamon, ""]
+    path.write_text("\n".join(lines) + "\n", encoding=FILE_ENCODING)
+
+
+def test_main_writes_summary_file_and_returns_zero(tmp_path: pathlib.Path) -> None:
+    census_path = tmp_path / "census.csv"
+    summary_path = tmp_path / "summary.csv"
+    _write_census(census_path)
+
+    status = cli.main([str(census_path), str(summary_path)])
+
+    assert status == 0
+    lines = summary_path.read_text(encoding=FILE_ENCODING).splitlines()
+    assert lines == [
+        ",".join(SUMMARY_COLUMNS),
+        f"{FUR_COLORS[0]},2",
+        f"{FUR_COLORS[1]},1",
+        f"{FUR_COLORS[2]},0",
+    ]
+
+
+def test_main_prints_one_line_per_colour(
+    tmp_path: pathlib.Path, capsys: pytest.CaptureFixture[str]
+) -> None:
+    census_path = tmp_path / "census.csv"
+    _write_census(census_path)
+
+    cli.main([str(census_path), str(tmp_path / "summary.csv")])
+
+    out_lines = capsys.readouterr().out.splitlines()
+    assert out_lines == [
+        f"{FUR_COLORS[0]}: 2",
+        f"{FUR_COLORS[1]}: 1",
+        f"{FUR_COLORS[2]}: 0",
+    ]
+
+
+def test_main_returns_2_and_writes_nothing_when_census_missing(
+    tmp_path: pathlib.Path, capsys: pytest.CaptureFixture[str]
+) -> None:
+    missing = tmp_path / "missing.csv"
+    summary_path = tmp_path / "summary.csv"
+
+    status = cli.main([str(missing), str(summary_path)])
+
+    captured = capsys.readouterr()
+    assert status == 2
+    assert not summary_path.exists()
+    assert captured.err.strip() == f"Census file not found: {missing}"
+    assert captured.out == ""