test: avoid chmod for unreadable log tests

test/cli/commands/test_log.py

@@ -4,6 +4,18 @@
 from chipcompiler.cli import main as cli_main
 
 
+def _make_path_unreadable(monkeypatch, unreadable_path):
+    real_open = open
+    unreadable_path = os.fspath(unreadable_path)
+
+    def open_unless_target(path, *args, **kwargs):
+        if os.fspath(path) == unreadable_path:
+            raise PermissionError("cannot read")
+        return real_open(path, *args, **kwargs)
+
+    monkeypatch.setattr("builtins.open", open_unless_target)
+
+
 class TestLog:
     def test_log_step_errors(self, tmp_path, capsys, create_cli_project):
         project_dir = create_cli_project()
@@ -536,43 +548,39 @@ def test_artifacts_log_disclosure_no_errors(
 class TestLogUnreadableFile:
     """AC-9: Unreadable log files return non-zero with OS error."""
 
-    def test_unreadable_log_returns_nonzero(self, tmp_path, capsys, create_cli_project):
+    def test_unreadable_log_returns_nonzero(
+        self, tmp_path, monkeypatch, capsys, create_cli_project
+    ):
         project_dir = create_cli_project()
         run_dir = os.path.join(project_dir, "runs", "default")
         step_dir = os.path.join(run_dir, "Synthesis_yosys", "log")
         os.makedirs(step_dir, exist_ok=True)
         log_path = os.path.join(step_dir, "synthesis.log")
         with open(log_path, "w") as f:
             f.write("content\n")
-        os.chmod(log_path, 0o000)
+        _make_path_unreadable(monkeypatch, log_path)
 
-        try:
-            rc = cli_main.run(["log", "synthesis", "--project", project_dir])
-            assert rc == 1
-            out = capsys.readouterr().out
-            assert "unreadable" in out
-        finally:
-            os.chmod(log_path, 0o644)
+        rc = cli_main.run(["log", "synthesis", "--project", project_dir])
+        assert rc == 1
+        out = capsys.readouterr().out
+        assert "unreadable" in out
 
-    def test_unreadable_log_jsonl(self, tmp_path, capsys, create_cli_project):
+    def test_unreadable_log_jsonl(self, tmp_path, monkeypatch, capsys, create_cli_project):
         project_dir = create_cli_project()
         run_dir = os.path.join(project_dir, "runs", "default")
         step_dir = os.path.join(run_dir, "Synthesis_yosys", "log")
         os.makedirs(step_dir, exist_ok=True)
         log_path = os.path.join(step_dir, "synthesis.log")
         with open(log_path, "w") as f:
             f.write("content\n")
-        os.chmod(log_path, 0o000)
+        _make_path_unreadable(monkeypatch, log_path)
 
-        try:
-            rc = cli_main.run(["log", "synthesis", "--jsonl", "--project", project_dir])
-            assert rc == 1
-            record = json.loads(capsys.readouterr().out.strip())
-            assert record["log_status"] == "unreadable"
-            assert "source" in record
-            assert "error" in record
-        finally:
-            os.chmod(log_path, 0o644)
+        rc = cli_main.run(["log", "synthesis", "--jsonl", "--project", project_dir])
+        assert rc == 1
+        record = json.loads(capsys.readouterr().out.strip())
+        assert record["log_status"] == "unreadable"
+        assert "source" in record
+        assert "error" in record
 
 
 class TestLogMultiSource:
@@ -958,23 +966,22 @@ def test_step_jsonl_unchanged(self, tmp_path, capsys, create_cli_project):
 class TestLogListingUnreadable:
     """Unreadable logs in listing mode must omit tail, keep path+inspect, no traceback."""
 
-    def test_unreadable_step_log_in_listing(self, tmp_path, capsys, create_cli_project):
+    def test_unreadable_step_log_in_listing(
+        self, tmp_path, monkeypatch, capsys, create_cli_project
+    ):
         project_dir = create_cli_project()
         run_dir = os.path.join(project_dir, "runs", "default")
         step_dir = os.path.join(run_dir, "Synthesis_yosys", "log")
         os.makedirs(step_dir, exist_ok=True)
         log_path = os.path.join(step_dir, "synthesis.log")
         with open(log_path, "w") as f:
             f.write("content\n")
-        os.chmod(log_path, 0o000)
-
-        try:
-            rc = cli_main.run(["log", "--project", project_dir])
-            assert rc == 0
-            out = capsys.readouterr().out
-            assert "tail:" not in out
-            assert "Synthesis_yosys" in out
-            assert "inspect:" in out
-            assert "Traceback" not in out
-        finally:
-            os.chmod(log_path, 0o644)
+        _make_path_unreadable(monkeypatch, log_path)
+
+        rc = cli_main.run(["log", "--project", project_dir])
+        assert rc == 0
+        out = capsys.readouterr().out
+        assert "tail:" not in out
+        assert "Synthesis_yosys" in out
+        assert "inspect:" in out
+        assert "Traceback" not in out

test/cli/rendering/test_log_view.py

@@ -1,5 +1,3 @@
-import os
-
 from chipcompiler.cli.inspection.log_view import (
     LineKind,
     annotate_log_lines,
@@ -852,17 +850,18 @@ def test_bel_and_backspace_stripped(self, tmp_path):
         result = tail_lines_for_log(str(log_file))
         assert result == ["abc", "done"]
 
-    def test_unreadable_file_returns_empty(self, tmp_path):
+    def test_unreadable_file_returns_empty(self, monkeypatch, tmp_path):
         from chipcompiler.cli.inspection.log_view import tail_lines_for_log
 
         log_file = tmp_path / "test.log"
         log_file.write_text("content\n")
-        os.chmod(str(log_file), 0o000)
-        try:
-            result = tail_lines_for_log(str(log_file))
-            assert result == []
-        finally:
-            os.chmod(str(log_file), 0o644)
+
+        def raise_permission_error(*args, **kwargs):
+            raise PermissionError("cannot read")
+
+        monkeypatch.setattr("builtins.open", raise_permission_error)
+        result = tail_lines_for_log(str(log_file))
+        assert result == []
 
 
 class TestListingTailRendering: