Initial Commit

tests/test_vm_working_directory.py

@@ -0,0 +1,103 @@
+#!/usr/bin/env python3
+"""The agent and its supervisor must mean the same thing by "here".
+
+    python3 tests/test_vm_working_directory.py
+
+WHY
+
+A Windows session was asked to write a PowerShell script, test it, and
+keep it. It did all three, perfectly, and the session was reported as a
+failure.
+
+The agent's `run` inherited whatever directory the guest agent happened to
+start in - on Windows, `C:\\Windows\\system32`. So `Set-Content
+Get-SystemInfo.ps1`, `Get-Content .\\Get-SystemInfo.ps1` and
+`powershell .\\Get-SystemInfo.ps1` all agreed with each other and all
+passed. The supervisor then re-ran the verification from the PROJECT
+folder, because that is the only place work survives, and found nothing
+there. The model read the failure, worked out what had happened, and spent
+a second whole session redoing it - roughly four minutes of machine time
+to move a file.
+
+Two rules come out of that, and this file holds both:
+
+  1. There is ONE definition of where a command runs, and both sides call
+     it. Two copies of this logic is exactly how they came to disagree.
+  2. It is the project folder, because that is the only thing that
+     outlives the machine. A file written anywhere else is deleted with
+     the disk.
+"""
+
+import ast
+import os
+import sys
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+VMD = os.path.join(HERE, "..", "vm", "vmd")
+sys.path.insert(0, VMD)
+
+FAILS: list[str] = []
+
+
+def check(label: str, condition: bool, detail: str = "") -> None:
+    if condition:
+        print(f"ok    {label}")
+    else:
+        FAILS.append(label)
+        print(f"FAIL  {label}\n      {detail}")
+
+
+import verify  # noqa: E402
+
+
+class FakeSession:
+    def __init__(self, os_name, share):
+        self.os_name = os_name
+        self.share = share
+
+
+# --- the prelude itself --------------------------------------------------
+linux = verify.working_directory_prelude(FakeSession("ubuntu", "/Pool/vmprojects/x"))
+windows = verify.working_directory_prelude(FakeSession("windows", "/Pool/vmprojects/x"))
+
+check("a Linux command starts in the project folder", "/mnt/project" in linux, linux)
+check("a Windows command starts in the project folder", "Z:\\" in windows, windows)
+check("the Windows prelude is PowerShell, not shell",
+      "Set-Location" in windows and "||" not in windows,
+      "PowerShell has no ||; this exact mistake reported correct work as a claim")
+check("the Linux prelude is shell", "cd " in linux)
+check("neither prelude can fail the command it prefixes",
+      "SilentlyContinue" in windows and "2>/dev/null" in linux,
+      "a missing share must not turn every command into an error")
+
+# With no project folder there is nowhere to keep anything, but a command
+# still has to run somewhere predictable.
+check("a session with no project folder still lands somewhere definite",
+      "C:\\" in verify.working_directory_prelude(FakeSession("windows", None))
+      and "/root" in verify.working_directory_prelude(FakeSession("ubuntu", None)))
+
+# --- and both sides use it -----------------------------------------------
+vmd_src = open(os.path.join(VMD, "vmd.py"), encoding="utf-8").read()
+verify_src = open(os.path.join(VMD, "verify.py"), encoding="utf-8").read()
+
+tree = ast.parse(vmd_src)
+run_verb = next(n for n in ast.walk(tree)
+                if isinstance(n, ast.FunctionDef) and n.name == "v_run")
+run_src = ast.get_source_segment(vmd_src, run_verb) or ""
+check("the agent's own run is given the prelude",
+      "working_directory_prelude" in run_src,
+      "this is the half that was missing, and it cost a whole extra session")
+check("the supervisor's re-run is given the same prelude",
+      "working_directory_prelude" in verify_src)
+
+# One definition, not two. The duplicate is how they drifted apart.
+check("the directory is decided in exactly one place",
+      verify_src.count('Set-Location -LiteralPath') == 1
+      and vmd_src.count("Set-Location") == 0,
+      "a second copy is how the agent and the supervisor came to disagree")
+
+print()
+if FAILS:
+    print(f"FAILED {len(FAILS)}")
+    raise SystemExit(1)
+print("the agent and its supervisor start in the same place, and it is the one that survives")