Fix disk-space boundary logic and add regression tests

src/sysforge/checks/core.py

@@ -17,10 +17,12 @@ def run(self, *, disk_threshold: float = 0.10) -> CheckResult:
         usage = disk_usage_summary(Path.home())
         percent_free = usage["percent_free"]
 
+        warn_limit = min(disk_threshold + WARN_THRESHOLD_MARGIN, 1.0)
+
         if percent_free <= disk_threshold:
             status = "fail"
             message = f"Low disk space: {percent_free:.2%} free (<= {disk_threshold:.0%})"
-        elif percent_free <= disk_threshold + WARN_THRESHOLD_MARGIN:
+        elif percent_free <= warn_limit:
             status = "warn"
             message = f"Disk space is getting low: {percent_free:.2%} free"
         else:

src/sysforge/cli.py

@@ -27,11 +27,14 @@ def _exit_code_from_summary(summary: object) -> int:
         return 2
     warn = summary.get("warn")
     fail = summary.get("fail")
+    passed = summary.get("pass")
     if (
         not isinstance(warn, int)
         or isinstance(warn, bool)
         or not isinstance(fail, int)
         or isinstance(fail, bool)
+        or not isinstance(passed, int)
+        or isinstance(passed, bool)
     ):
         return 2
     if fail > 0:

tests/test_checks.py

@@ -58,3 +58,15 @@ def fake_usage(percent_free: float) -> dict[str, float]:
         lambda _: fake_usage(0.5),
     )
     assert DiskSpaceCheck().run(disk_threshold=0.1).status == "pass"
+
+    monkeypatch.setattr(
+        "sysforge.checks.core.disk_usage_summary",
+        lambda _: fake_usage(0.15),
+    )
+    assert DiskSpaceCheck().run(disk_threshold=0.1).status == "warn"
+
+    monkeypatch.setattr(
+        "sysforge.checks.core.disk_usage_summary",
+        lambda _: fake_usage(0.151),
+    )
+    assert DiskSpaceCheck().run(disk_threshold=0.1).status == "pass"

tests/test_cli.py

@@ -93,6 +93,15 @@ def test_doctor_malformed_summary_wrong_types_exits_2(monkeypatch) -> None:
     assert result.exit_code == 2
 
 
+def test_doctor_malformed_summary_pass_wrong_type_exits_2(monkeypatch) -> None:
+    monkeypatch.setattr(
+        "sysforge.cli.run_checks",
+        lambda disk_threshold: {"results": [], "summary": {"pass": "1", "warn": 0, "fail": 0}},
+    )
+    result = runner.invoke(app, ["doctor"])
+    assert result.exit_code == 2
+
+
 def test_doctor_respects_pretty_option(monkeypatch, tmp_path: Path) -> None:
     monkeypatch.setattr(
         "sysforge.cli.run_checks",