1 files changed, 97 insertions, 0 deletions
diff --git a/graph/test_transport.py b/graph/test_transport.py
new file mode 100644
index 00000000..2d81a274
--- /dev/null
+++ b/graph/test_transport.py
@@ -0,0 +1,97 @@
+"""Check HTTP assets and a delayed, fragmented WebSocket upgrade.
+
+Build the chapter first, then run: python graph/test_transport.py chapter25
+Uses only the Python standard library; does not launch a browser.
+"""
+
+from pathlib import Path
+import socket
+import subprocess
+import sys
+import time
+import urllib.request
+
+
+def check(chapter):
+    root = Path(__file__).resolve().parent.parent
+    number = int(chapter.removeprefix("chapter"))
+    assert 18 <= number <= 25
+    chapter_dir = root / chapter
+    package = "com.seaofnodes.simple." + ("print." if number >= 20 else "")
+    log = root / "build" / "graph-transport" / (chapter + ".log")
+    log.parent.mkdir(parents=True, exist_ok=True)
+    with log.open("w") as output:
+        process = subprocess.Popen(
+            ["java", "-ea", "-Dsimple.graph.open=false", "-cp",
+             "build/classes/main", package + "JSViewer"],
+            cwd=chapter_dir, stdout=output, stderr=subprocess.STDOUT)
+        try:
+            deadline = time.monotonic() + 10
+            url = None
+            while time.monotonic() < deadline and process.poll() is None:
+                lines = log.read_text().splitlines()
+                addresses = [line.removeprefix("Graph viewer: ") for line in lines
+                             if line.startswith("Graph viewer: ")]
+                if addresses:
+                    url = addresses[0]
+                    break
+                time.sleep(.05)
+            assert url and url.startswith("http://127.0.0.1:"), log.read_text()
+            # The browser must be able to load all assets before connecting.
+            for asset in ("index.html", "viewer.js", "vendor/d3.v7.min.js",
+                          "vendor/d3-graphviz.js", "vendor/graphviz.umd.js"):
+                with urllib.request.urlopen(url.rsplit("/", 1)[0] + "/" + asset,
+                                            timeout=3) as response:
+                    assert response.status == 200
+                    assert response.read() == (root / "graph/web" / asset).read_bytes()
+            with socket.create_connection(("127.0.0.1", 12345), timeout=3) as client:
+                # Reproduces the old ready() race: accept precedes any headers.
+                time.sleep(.3)
+                client.sendall(b"GET / HTTP/1.1\r\nHost: localhost:12345\r\n")
+                time.sleep(.1)
+                client.sendall(b"Upgrade: websocket\r\nConnection: Upgrade\r\n"
+                               b"Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==\r\n"
+                               b"Sec-WebSocket-Version: 13\r\n")
+                # Even with the key present, the header block is not complete.
+                client.settimeout(.2)
+                try:
+                    early = client.recv(1)
+                except socket.timeout:
+                    pass
+                else:
+                    raise AssertionError("Responded before headers ended: " + repr(early))
+                client.settimeout(3)
+                client.sendall(b"\r\n")
+                with client.makefile("rb") as stream:
+                    assert stream.readline() == b"HTTP/1.1 101 Switching Protocols\r\n"
+                    headers = []
+                    while True:
+                        line = stream.readline()
+                        assert line, "Connection closed during upgrade"
+                        if line == b"\r\n":
+                            break
+                        headers.append(line)
+                    assert b"Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=\r\n" in headers
+                    assert stream.read(3) == b"\x81\x01!", "Missing source request"
+                    # Masked 'null' asks the compiler to exit normally.
+                    mask = b"abcd"
+                    payload = bytes(byte ^ mask[i % 4] for i, byte in enumerate(b"null"))
+                    client.sendall(b"\x81\x84" + mask + payload)
+                    assert stream.read(2) == b"\x88\x00", "Invalid close frame"
+            assert process.wait(timeout=5) == 0, log.read_text()
+            # The HTTP server must not outlive the compiler session.
+            try:
+                urllib.request.urlopen(url, timeout=.5)
+            except OSError:
+                pass
+            else:
+                raise AssertionError("HTTP server survived viewer shutdown")
+        finally:
+            if process.poll() is None:
+                process.terminate()
+                process.wait(timeout=5)
+    print(chapter + ": HTTP assets, fragmented upgrade, greeting, and shutdown passed")
+
+
+if __name__ == "__main__":
+    check(sys.argv[1] if len(sys.argv) > 1 else "chapter25")