test: read the WebRTC transport's source as a set of files

Source-reading tests take their text from node_source (node) and node_tree
(hub): webrtc_server.py plus anything under transport/webrtc/, so a check
for something's absence keeps reading the code it guards if that code moves.
test_node_source_scope holds the boundary.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/packages/meshbay-hub/tests/node_tree.py b/packages/meshbay-hub/tests/node_tree.py
new file mode 100644
index 0000000..8704492
--- /dev/null
+++ b/packages/meshbay-hub/tests/node_tree.py
@@ -0,0 +1,54 @@
+"""
+The node's WebRTC transport, as source text, for the hub tests that check a
+client contract against what the node actually sends.
+
+Read from the tree rather than imported, so these tests keep working in a
+checkout without the node installed. The file set is derived — the transport
+is `webrtc_server.py` and whatever has been split out of it under
+`transport/webrtc/` — so that code moving between those files does not leave a
+test reading a file its subject has left. The node suite's `node_source.py`
+draws the same line and holds it with `test_node_source_scope.py`.
+"""
+
+import ast
+from pathlib import Path
+
+# parents[2] is `packages/`: the tests live at packages/meshbay-hub/tests/. A
+# wrong index here does not fail anything — every test using it skips, which
+# is worse than not having them: a green run that measured nothing. That
+# happened once.
+TRANSPORT = (Path(__file__).resolve().parents[2] / "meshbay-node" / "src"
+             / "meshbay_node" / "transport")
+SERVER = TRANSPORT / "webrtc_server.py"
+
+
+def available() -> bool:
+    return SERVER.exists()
+
+
+def webrtc_files() -> list[Path]:
+    files = [SERVER]
+    package = TRANSPORT / "webrtc"
+    if package.is_dir():
+        files += sorted(p for p in package.rglob("*.py")
+                        if "__pycache__" not in p.parts)
+    return files
+
+
+def webrtc_source() -> str:
+    return "\n".join(p.read_text(encoding="utf-8") for p in webrtc_files())
+
+
+def method(name: str) -> str:
+    """The text of one method of a class in the transport, found by name."""
+    found = []
+    for path in webrtc_files():
+        text = path.read_text(encoding="utf-8")
+        for node in ast.walk(ast.parse(text)):
+            if isinstance(node, ast.ClassDef):
+                for member in node.body:
+                    if isinstance(member, (ast.FunctionDef, ast.AsyncFunctionDef)) \
+                            and member.name == name:
+                        found.append(ast.get_source_segment(text, member, padded=True))
+    assert len(found) == 1, f"{name}: expected one definition, found {len(found)}"
+    return found[0]