Draw the tree the branch list can only spell out

The Branches panel says which lines exist. It cannot say where they parted
or how much story each one is, because those are the two numbers `GET
/branches` already answers and a list has nowhere to put them. A ⌗ See the
tree button opens a map: one horizontal lane per branch, running from the
moment it left its parent to the moment it ends, joined to the parent by an
elbow at the fork. The horizontal axis is the story's own clock, so two
lanes at the same x are at the same moment and a short branch reads as
short.

This is a branch map, not the per-node map SP7 refused, and that is the
whole reason it was cheap. Lanes are bounded by branch count, not node
count, so the 600-node windowing problem never arrives. It reads the single
request the rail already made and nothing else.

`branches.js` holds the tree maths and `BranchMap.jsx` the drawing. Play.jsx
gives up its private copies of branchLabel and orderBranches: the panel and
the map now label and order a branch through the same functions, so a branch
cannot be called two things by the two views. The three operations stay in
BranchPanel and are passed down, and `run` answers whether it worked so
neither view clears a half-typed name on a refusal.

Three things came out of driving it, none of which a test could have seen.
`clientWidth` counts the canvas padding the ResizeObserver leaves out, so
the first paint drew an svg 24px wider than its box — and the observer's
initial observation never arrived here, so dropping the seed left the map
never drawing at all. Both are needed and the seed subtracts the padding.
Only the name was being clipped, not the meta line under it, so a late fork
ran its text off the right edge; both are clipped now, and a lane starting
in the right third hangs its labels back over the fork, where its own band
guarantees nothing to collide with. And the delete rule lived in the server
and in the map but not in the list, which offered Delete on a branch the
head was forked from and answered with a toast from the server's 400.
`headLineage` is the client's copy of that rule and both views use it; the
server stays the authority.

`tools/tree_fixture.py` is the counterpart to `tools/branch_fixture.py` —
four branches at three fork depths, one forked off a fork. With no frontend
test runner it is the whole of the map's coverage, and it exists to be
looked at. Nothing in the backend changed; the 440 tests pass unmoved.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DfMCsN1KBLsTqMkj5hSgrY
This commit is contained in:
parththakkar106
2026-08-20 03:38:17 +05:30
co-authored by Claude Opus 5
parent ff190d2453
commit c8e081e9d6
6 changed files with 832 additions and 46 deletions
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"""A tree with a shape worth drawing — for driving the branch map by hand.
`tools.branch_fixture` builds two branches of equal length, which is the case
the panel-refresh bug needed and the smallest tree that proves a switch. A map
needs the other case: several lines, leaving at different moments, one of them
forked off a fork, so lanes have to nest and the moment axis has to mean
something. Four branches, depths 26 / 20 / 22 / 22, forks at 5, 15 and 17.
There is no frontend test runner, so this is the whole of the map's coverage:
it exists to be looked at.
cd backend
.venv/Scripts/python.exe -m tools.tree_fixture /tmp/tree.db
AIDND_DB_PATH=/tmp/tree.db .venv/Scripts/python.exe \
-m uvicorn app.main:app --port 8010
Then open http://127.0.0.1:8010/play/1, Branches → See the tree. The SPA is
served out of `frontend/dist`, so run `npm run build` first if it is stale.
No LLM is called: the provider is scripted.
"""
import os
import sys
sys.path.insert(0, os.getcwd())
OUT = sys.argv[1] if len(sys.argv) > 1 else "treefixture.db"
if os.path.exists(OUT):
os.remove(OUT)
os.environ["AIDND_DB_PATH"] = OUT
os.environ.pop("AIDND_DATABASE_URL", None)
os.environ.pop("DATABASE_URL", None)
os.environ.pop("AIDND_MULTI_USER", None)
from fastapi.testclient import TestClient # noqa: E402
from sqlalchemy import text # noqa: E402
from app import auth, limits, models # noqa: E402
from app.database import Base, SessionLocal, engine # noqa: E402
from app.main import app # noqa: E402
from app.migrations import LATEST_VERSION # noqa: E402
from app.routers import adventures # noqa: E402
SCHEMA = {"player": {"hp": {"min": 0, "max": 100, "initial": 100}}}
PROSE = [
"The stair turns and the lantern light goes with it.",
"Water somewhere ahead, and it is not running.",
"A door, and the frame around it is warm to the touch.",
"Something has been eating the salt off the stones.",
"The passage opens and the ceiling goes out of reach.",
"A shape at the edge of the light declines to move.",
"The floor here has been swept, recently, by something patient.",
"You find the second lantern, still warm, and nobody holding it.",
]
class ScriptedProvider:
calls = 0
def __init__(self, *a, **k):
pass
async def generate(self, parts, *, temperature, max_tokens):
i = ScriptedProvider.calls
ScriptedProvider.calls += 1
yield ("text", f"{PROSE[i % len(PROSE)]}\n```state\n{{\"player.hp\": -2}}\n```")
Base.metadata.create_all(bind=engine)
db = SessionLocal()
user = models.User(is_guest=False, email=None)
db.add(user)
db.flush()
db.add(models.Settings(user_id=user.id, api_key="enc:dummy", model="test-model"))
scenario = models.Scenario(user_id=user.id, title="Thornwick", stat_schema=SCHEMA)
db.add(scenario)
db.flush()
adv = models.Adventure(
user_id=user.id, title="The Hollow Beneath Thornwick", scenario_id=scenario.id,
script_state={}, world_state={"player": {"hp": 100}}, memory_bank_enabled=True,
)
db.add(adv)
db.flush()
db.add(models.Action(
adventure_id=adv.id, index=0, type="start",
text="The cellar door has been shut since your grandmother died."))
db.commit()
adv_id = adv.id
db.close()
adventures.OpenAICompatibleProvider = ScriptedProvider
auth.resolve_provider_config = lambda s: auth.ProviderConfig(
"http://fake", "k", "test-model", False)
limits.rate_limit = lambda *a, **k: None
limits.check_row_cap = lambda *a, **k: None
client = TestClient(app)
base = f"/api/adventures/{adv_id}"
def play(n=1):
for _ in range(n):
r = client.post(f"{base}/actions", json={"type": "do", "text": "go on"})
assert r.status_code == 200, r.text
def retry_and_get_discarded():
"""Retry the last turn and hand back the take the story left behind."""
before = live_ai_ids()
r = client.post(f"{base}/retry")
assert r.status_code == 200, r.text
db = SessionLocal()
dead = [a.id for a in db.query(models.Action)
.filter(models.Action.adventure_id == adv_id, models.Action.type == "ai")
.order_by(models.Action.id) if not a.live]
db.close()
assert dead, "retry left no discarded take"
# The one that was live a moment ago is the one this retry replaced.
return [i for i in dead if i in before][-1]
def live_ai_ids():
db = SessionLocal()
out = [a.id for a in db.query(models.Action)
.filter(models.Action.adventure_id == adv_id, models.Action.type == "ai")
.order_by(models.Action.id) if a.live]
db.close()
return out
def fork(action_id):
r = client.post(f"{base}/actions/{action_id}/fork")
assert r.status_code == 200, r.text
def branches():
return client.get(f"{base}/branches").json()
# ---- the first telling: a long line, with two turns retried along it ----
play(3)
early = retry_and_get_discarded()
play(6)
late = retry_and_get_discarded()
play(4)
root = branches()[0]["id"]
client.patch(f"{base}/branches/{root}", json={"name": "The hard way down"})
# ---- a line that left early, and a line that left it again ----
fork(early) # now reading the early attempt, on its own branch
play(5)
mid = retry_and_get_discarded()
play(2)
second = [b for b in branches() if b["is_head"]][0]["id"]
client.patch(f"{base}/branches/{second}", json={"name": "Down the other stair"})
fork(mid) # a fork off a fork
play(3)
# ---- and one more off the first telling, much later ----
client.post(f"{base}/branches/{root}/switch")
fork(late)
play(2)
# Leave the reader on the deepest line, so the map opens on a nested lane.
deep = [b for b in branches() if b["parent_branch_id"] not in (None,)
and b["name"] is None][0]
client.post(f"{base}/branches/{deep['id']}/switch")
with engine.begin() as conn:
conn.execute(text(f"PRAGMA user_version = {LATEST_VERSION}"))
for b in branches():
print(f" branch {b['id']}: name={b['name']!r} parent={b['parent_branch_id']} "
f"fork_depth={b['fork_depth']} depth={b['depth']} own={b['own_actions']} "
f"head={b['is_head']}")
print(f"fixture written: {OUT} (adventure {adv_id})")