web: the composer, served behind the existing proxy chain

A browser page with controls on one side and the cross section on the other. Three separately classed layers: printed material, the cavities the stock passes through, and the stock drawn inside its cavity so the fit gap is visible. Under it the report and the design record, so the identity of a part is visible while tuning rather than discovered afterwards. Standard library only, no framework, no build step, no new dependency.

Binding comes from /etc/mechcomp/mechcomp.env, which already declared 10.20.0.10:8770. An earlier draft invented a port on 0.0.0.0, which would have placed a second unproxied plaintext copy beside the proxied one. The fallback with no env file is loopback, never every interface: behind a proxy, binding too narrowly fails loudly as a 502 and too widely fails silently as an open service.

Controls are filtered to the selected profile, with no catch all group. A knob that moves nothing is worse than an absent one.

Renderer tests assert what an eye cannot: the vertical flip happens exactly once, holes render as holes, and the cavity is larger than the stock inside it. Seven mutations on the renderer, all caught.
This commit is contained in:
2026-09-11 06:46:23 -05:00
parent e921cacf0e
commit 14514b0bac
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"""
Render a cross-section as SVG.
WHY SEPARATELY CLASSED PARTS
ROADMAP section 4 gives this as the reason the port exists at all: the
outline, each stock cavity and the stock itself are emitted as distinct
classed groups, so a viewer can highlight or hide them independently. A
single flattened silhouette would have been far easier and would not have
justified leaving OpenSCAD.
COORDINATES
Geometry has +Y up; SVG has +Y down. The whole drawing is flipped once in a
wrapping transform rather than by negating coordinates, so the paths in the
file remain the geometry's own numbers and can be read against the report.
HOLES
A region is a list of rings, some of which are holes, and their winding
direction is not something this module wants to depend on. Every ring of a
region goes into one path with ``fill-rule="evenodd"``, which renders holes
correctly whichever way they wind.
"""
from __future__ import annotations
from typing import Iterable, List, Optional, Sequence, Tuple
Point = Tuple[float, float]
Path = List[Point]
Region = Sequence[Path]
def _fmt(v: float) -> str:
"""Trim to 4 decimal places -- well below anything visible at any zoom."""
return ("%.4f" % v).rstrip("0").rstrip(".") or "0"
def path_d(region: Region) -> str:
"""One SVG path definition covering every ring of a region."""
parts: List[str] = []
for ring in region:
if len(ring) < 3:
continue
parts.append("M " + " L ".join("%s %s" % (_fmt(x), _fmt(y))
for x, y in ring) + " Z")
return " ".join(parts)
def bounds(regions: Iterable[Region]) -> Tuple[float, float, float, float]:
xs: List[float] = []
ys: List[float] = []
for region in regions:
for ring in region:
for x, y in ring:
xs.append(x)
ys.append(y)
if not xs:
return (-1.0, -1.0, 1.0, 1.0)
return (min(xs), min(ys), max(xs), max(ys))
def render(section: Region,
cavities: Optional[Region] = None,
stock: Optional[Sequence[Path]] = None,
margin: float = 3.0,
width_px: int = 520) -> str:
"""
The cross-section as a standalone SVG document.
``section`` is the printed material. ``cavities`` are the voids the stock
passes through. ``stock`` is the stock itself, drawn inside its cavity so
the fit gap is visible -- which is the whole point of looking at it.
"""
regions: List[Region] = [section]
if cavities:
regions.append(cavities)
if stock:
regions.append(list(stock))
x0, y0, x1, y1 = bounds(regions)
x0 -= margin
y0 -= margin
x1 += margin
y1 += margin
w = x1 - x0
h = y1 - y0
height_px = int(round(width_px * (h / w))) if w > 0 else width_px
out: List[str] = [
'<svg xmlns="http://www.w3.org/2000/svg" '
'viewBox="%s %s %s %s" width="%d" height="%d" '
'class="mechcomp-section">'
% (_fmt(x0), _fmt(y0), _fmt(w), _fmt(h), width_px, height_px),
'<style>',
'.mc-material { fill: #b9c6d4; stroke: #33414f; stroke-width: 0.25; }',
'.mc-cavity { fill: #f4b183; stroke: #a8642a; stroke-width: 0.15; }',
'.mc-stock { fill: #55606c; stroke: none; }',
'</style>',
# One flip for the whole drawing. Everything below is in geometry
# coordinates, so a path here can be read against the report directly.
'<g transform="translate(0,%s) scale(1,-1)">' % _fmt(y0 + y1),
]
out.append('<g class="mc-layer-material">'
'<path class="mc-material" fill-rule="evenodd" d="%s"/></g>'
% path_d(section))
if cavities:
out.append('<g class="mc-layer-cavity">'
'<path class="mc-cavity" fill-rule="evenodd" d="%s"/></g>'
% path_d(cavities))
if stock:
out.append('<g class="mc-layer-stock">'
'<path class="mc-stock" fill-rule="evenodd" d="%s"/></g>'
% path_d(list(stock)))
out.append('</g>')
out.append('</svg>')
return "\n".join(out)
def render_result(result, geo=None) -> str:
"""
Render whatever ``build()`` returned.
Cavities and stock are drawn when the geometry layer can supply them, and
quietly omitted when it cannot -- a picture of the material alone is still
useful, and a viewer should not fail because a helper moved.
"""
section = result.section
cavities = None
stock = None
g = geo if geo is not None else getattr(result, "geo", None)
members = getattr(result, "members", None)
if g is not None and members:
try:
from .geom.join import cavity_region
cavities = cavity_region(members, g)
except Exception: # noqa: BLE001
cavities = None
try:
from .geom.records import strap_path
stock = [strap_path(m, g) for m in members]
except Exception: # noqa: BLE001
stock = None
return render(section, cavities, stock)
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"""Mechanical Compiler - web.""" from .app import build_payload, families, serve
__all__ = ["build_payload", "families", "serve"]
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from .app import serve
serve()
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"""
The composer: a browser page with controls on one side and the part on the other.
Standard library only -- ``http.server``. No framework, no build step, no new
dependency. That is a deliberate constraint for a first usable interface: it
runs anywhere the port already runs, and there is nothing to install or
configure before it will show you a picture.
python -m mechcomp.web # then open the URL it prints
WHAT IT SHOWS
Change a number, see the part. Under it, the report the compiler produced
and the design record that would ship with the model -- so the identity of
what you are looking at is visible while you tune, not discovered
afterwards.
WHAT IT DOES NOT DO
It does not export STL, and it does not persist anything. It is a viewer and
a control panel over ``build()``. Rejections are shown as messages rather
than errors, because a rejection is the compiler doing its job.
"""
from __future__ import annotations
import json
import os
import traceback
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from typing import Any, Dict, List, Tuple
from urllib.parse import parse_qs, urlparse
from mechcomp import svg
# The deployment's own answers. STAGING-STATE.md section 1 records this file
# as root:mechcomp 0640, and the service user can read it.
ENV_FILE = "/etc/mechcomp/mechcomp.env"
# Parameters that apply to every profile, in the order they make sense to a
# person: what the stock is, how it fits, then how thick the printed walls are.
COMMON_GROUPS: List[Tuple[str, List[str]]] = [
("Stock", ["strap_width_mm", "strap_thickness_mm", "bundle_count"]),
("Fit", ["fit_clearance_mm"]),
("Walls", ["inside_wall_thickness_mm", "outside_wall_thickness_mm",
"edge_wall_thickness_mm", "min_wall_mm"]),
("Model", ["preview_length_mm", "member_length_ft", "material_density_g_cm3",
"facets"]),
]
# Which parameter prefixes belong to which profile, so a person is not shown
# thirty controls of which twenty are irrelevant to what they selected.
PROFILE_PREFIX: Dict[str, Tuple[str, ...]] = {
"Equilateral Triangle": ("ring_corner_", "equilateral_"),
"General Triangle": ("ring_corner_", "general_triangle_"),
"A Frame": ("a_frame_",),
"Y": ("y_",),
"T": ("t_",),
"Three-Fin": ("three_fin_",),
"Square": ("ring_corner_",),
"Rectangle": ("ring_corner_", "rectangle_"),
"Diamond": ("ring_corner_",),
"Cross": ("ring_corner_", "cross_"),
"Four-Fin": ("four_fin_",),
}
def families() -> Dict[str, Any]:
from mechcomp.profiles.four_x import FAMILY as FOUR_X
from mechcomp.profiles.three_x import FAMILY as THREE_X
return {"3x": THREE_X, "4x": FOUR_X}
def profile_params(family, profile: str) -> List[Tuple[str, List[str]]]:
"""Common groups, then the parameters specific to the selected profile."""
defaults = family.defaults
used = {k for _, keys in COMMON_GROUPS for k in keys}
groups: List[Tuple[str, List[str]]] = []
for title, keys in COMMON_GROUPS:
present = [k for k in keys if k in defaults]
if present:
groups.append((title, present))
prefixes = PROFILE_PREFIX.get(profile, ())
specific = [k for k in sorted(defaults)
if k not in used and any(k.startswith(p) for p in prefixes)]
if specific:
groups.append((profile, specific))
# Deliberately no catch-all group. Anything not common and not matching
# this profile's prefixes belongs to a different profile and does
# nothing to the part on screen. A knob that moves nothing is worse than
# an absent one. If a parameter is unreachable, add its prefix to
# PROFILE_PREFIX rather than restoring a fallback.
return groups
def build_payload(family_name: str, profile: str,
overrides: Dict[str, Any]) -> Dict[str, Any]:
from mechcomp.profiles import ProfileRejected, build
family = families()[family_name]
typed: Dict[str, Any] = {}
for key, raw in overrides.items():
if key not in family.defaults:
continue
default = family.defaults[key]
try:
if isinstance(default, bool):
typed[key] = raw not in ("", "0", "false", "False")
elif isinstance(default, int) and not isinstance(default, bool):
typed[key] = int(float(raw))
elif isinstance(default, float):
typed[key] = float(raw)
else:
typed[key] = raw
except (TypeError, ValueError):
continue
payload: Dict[str, Any] = {
"family": family_name,
"profile": profile,
"groups": [[title, keys] for title, keys in profile_params(family, profile)],
"defaults": {k: family.defaults[k] for k in family.defaults},
"values": {**family.defaults, **typed},
"profiles": sorted(family.catalogue),
}
try:
result = build(family=family_name, profile=profile, params=typed)
except ProfileRejected as exc:
payload["ok"] = False
payload["message"] = str(exc)
return payload
except Exception as exc: # noqa: BLE001
payload["ok"] = False
payload["message"] = "%s: %s" % (type(exc).__name__, exc)
payload["trace"] = traceback.format_exc()
return payload
payload["ok"] = True
payload["svg"] = svg.render_result(result)
payload["report"] = {k: result.report[k] for k in sorted(result.report)}
payload["record"] = result.record.render() if result.record else ""
payload["input_id"] = result.record.input_id if result.record else ""
return payload
PAGE = """<!doctype html>
<html lang="en"><head><meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>Mechanical Compiler</title>
<style>
:root { --ink:#1c2530; --line:#d3dae1; --bg:#f7f9fb; --accent:#2f6f9f; }
* { box-sizing:border-box; }
body { margin:0; font:14px/1.5 ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
color:var(--ink); background:var(--bg); }
header { padding:14px 20px; background:#fff; border-bottom:1px solid var(--line); }
header h1 { margin:0; font-size:16px; font-weight:640; letter-spacing:.01em; }
header p { margin:3px 0 0; font-size:12px; color:#66727e; }
.wrap { display:grid; grid-template-columns:340px 1fr; gap:0; align-items:start; }
.panel { padding:16px 20px; border-right:1px solid var(--line); background:#fff;
height:calc(100vh - 62px); overflow-y:auto; }
.stage { padding:20px; }
fieldset { border:0; margin:0 0 18px; padding:0; }
legend { font-size:11px; text-transform:uppercase; letter-spacing:.09em;
color:#7b8794; margin-bottom:7px; font-weight:640; }
label { display:grid; grid-template-columns:1fr 92px; gap:8px; align-items:center;
margin-bottom:6px; font-size:12.5px; }
label span { overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
input,select { font:inherit; font-size:12.5px; padding:4px 7px;
border:1px solid var(--line); border-radius:5px; background:#fff; width:100%; }
input:focus,select:focus { outline:2px solid var(--accent); outline-offset:-1px; }
.figure { background:#fff; border:1px solid var(--line); border-radius:9px;
padding:18px; display:inline-block; min-width:300px; min-height:200px; }
.bad { background:#fff4ed; border:1px solid #f0c3a2; border-radius:9px;
padding:14px 16px; max-width:640px; }
.bad b { display:block; margin-bottom:5px; font-size:12px; text-transform:uppercase;
letter-spacing:.07em; color:#a8642a; }
.cols { display:grid; grid-template-columns:1fr 1fr; gap:18px; margin-top:20px; max-width:900px; }
details { background:#fff; border:1px solid var(--line); border-radius:9px; padding:11px 14px; }
summary { cursor:pointer; font-size:12px; text-transform:uppercase;
letter-spacing:.07em; color:#7b8794; font-weight:640; }
pre { margin:10px 0 0; font:11.5px/1.55 ui-monospace,SFMono-Regular,Menlo,monospace;
white-space:pre-wrap; word-break:break-word; max-height:340px; overflow-y:auto; }
.ident { font:11.5px ui-monospace,Menlo,monospace; color:#66727e; margin-top:9px; }
.toggles { margin-bottom:12px; font-size:12.5px; }
.toggles label { display:inline-flex; grid-template-columns:none; gap:5px; margin-right:14px; }
.toggles input { width:auto; }
</style></head><body>
<header>
<h1>Mechanical Compiler</h1>
<p>Change a number, see the part. Every setting produces a different design id.</p>
</header>
<div class="wrap">
<div class="panel">
<fieldset>
<legend>Member</legend>
<label><span>family</span><select id="family"></select></label>
<label><span>profile</span><select id="profile"></select></label>
</fieldset>
<div id="controls"></div>
</div>
<div class="stage">
<div class="toggles">
<label><input type="checkbox" id="t-material" checked> material</label>
<label><input type="checkbox" id="t-cavity" checked> cavities</label>
<label><input type="checkbox" id="t-stock" checked> stock</label>
</div>
<div id="out"></div>
<div class="cols">
<details open><summary>Report</summary><pre id="report"></pre></details>
<details><summary>Design record</summary><pre id="record"></pre></details>
</div>
</div>
</div>
<script>
let state = { family:"3x", profile:"Y", values:{} };
async function refresh(sendValues) {
const q = new URLSearchParams();
q.set("family", state.family);
q.set("profile", state.profile);
if (sendValues) for (const [k,v] of Object.entries(state.values)) q.set(k, v);
const data = await (await fetch("/api/build?" + q.toString())).json();
const fam = document.getElementById("family");
if (!fam.options.length) {
for (const f of ["3x","4x"]) fam.add(new Option(f, f));
fam.value = state.family;
fam.onchange = () => { state.family = fam.value; state.values = {}; refresh(false); };
}
const prof = document.getElementById("profile");
prof.innerHTML = "";
for (const p of data.profiles) prof.add(new Option(p, p));
prof.value = data.profile;
prof.onchange = () => { state.profile = prof.value; refresh(true); };
state.values = {};
const box = document.getElementById("controls");
box.innerHTML = "";
for (const [title, keys] of data.groups) {
const fs = document.createElement("fieldset");
fs.innerHTML = "<legend>" + title + "</legend>";
for (const k of keys) {
const v = data.values[k];
state.values[k] = v;
const lab = document.createElement("label");
const name = document.createElement("span");
name.textContent = k.replace(/_mm$|_deg$|_ft$/, "").replace(/_/g, " ");
name.title = k;
const inp = document.createElement("input");
inp.value = v;
if (typeof v === "number") { inp.type = "number"; inp.step = "any"; }
inp.onchange = () => { state.values[k] = inp.value; refresh(true); };
lab.append(name, inp);
fs.append(lab);
}
box.append(fs);
}
const out = document.getElementById("out");
if (data.ok) {
out.innerHTML = '<div class="figure">' + data.svg + '</div>'
+ '<div class="ident">design ' + data.input_id + '</div>';
document.getElementById("report").textContent =
Object.entries(data.report).map(([k,v]) => k + " = " + v).join("\\n");
document.getElementById("record").textContent = data.record;
applyToggles();
} else {
out.innerHTML = '<div class="bad"><b>Not buildable</b>' + escapeHtml(data.message) + '</div>';
}
}
function escapeHtml(s) {
return String(s).replace(/[&<>]/g, c => ({"&":"&amp;","<":"&lt;",">":"&gt;"}[c]));
}
function applyToggles() {
for (const [id, cls] of [["t-material","mc-layer-material"],
["t-cavity","mc-layer-cavity"],
["t-stock","mc-layer-stock"]]) {
const on = document.getElementById(id).checked;
document.querySelectorAll("." + cls).forEach(g => g.style.display = on ? "" : "none");
}
}
for (const id of ["t-material","t-cavity","t-stock"])
document.getElementById(id).onchange = applyToggles;
refresh(false);
</script></body></html>
"""
class Handler(BaseHTTPRequestHandler):
def log_message(self, fmt, *args):
pass
def _send(self, code: int, body: bytes, ctype: str):
self.send_response(code)
self.send_header("Content-Type", ctype)
self.send_header("Content-Length", str(len(body)))
self.end_headers()
self.wfile.write(body)
def do_GET(self):
parsed = urlparse(self.path)
if parsed.path in ("/", "/index.html"):
self._send(200, PAGE.encode("utf-8"), "text/html; charset=utf-8")
return
if parsed.path == "/api/build":
q = {k: v[0] for k, v in parse_qs(parsed.query).items()}
family = q.pop("family", "3x")
profile = q.pop("profile", "Y")
try:
payload = build_payload(family, profile, q)
except Exception as exc: # noqa: BLE001
payload = {"ok": False,
"message": "%s: %s" % (type(exc).__name__, exc),
"profiles": [], "groups": [], "values": {}}
self._send(200, json.dumps(payload).encode("utf-8"),
"application/json; charset=utf-8")
return
self._send(404, b"not found", "text/plain; charset=utf-8")
def read_env_file(path: str = ENV_FILE) -> Dict[str, str]:
"""
Parse the deployment's environment file.
Plain ``KEY=value`` lines, ``#`` comments, no shell. Absent or unreadable
is not an error -- the composer must still run from a checkout on a
machine that has no deployment at all.
"""
out: Dict[str, str] = {}
try:
with open(path, encoding="utf-8") as fh:
for line in fh:
line = line.strip()
if not line or line.startswith("#") or "=" not in line:
continue
key, _, value = line.partition("=")
out[key.strip()] = value.split("#")[0].strip()
except OSError:
pass
return out
def resolve_binding(env_file: str = ENV_FILE) -> Tuple[str, int]:
"""
Where to listen: the real environment first, then the deployment file.
THE FALLBACK IS LOOPBACK, NOT 0.0.0.0, AND THAT IS THE POINT.
This service sits behind nginx on CT 101, which terminates TLS and
proxies to the service address. Binding every interface would place a
second unproxied plaintext copy beside it. Behind a proxy, binding
too narrowly fails loudly as a 502; binding too widely fails silently
as an open service nobody notices. Prefer the loud failure.
"""
env = read_env_file(env_file)
host = (os.environ.get("MECHCOMP_BIND")
or env.get("MECHCOMP_BIND")
or "127.0.0.1")
raw_port = (os.environ.get("MECHCOMP_PORT")
or env.get("MECHCOMP_PORT")
or "8770")
try:
port = int(raw_port)
except (TypeError, ValueError):
port = 8770
return host, port
def base_url(env_file: str = ENV_FILE) -> str:
"""The URL a person actually types. Empty when nothing declares one."""
env = read_env_file(env_file)
return os.environ.get("MECHCOMP_BASE_URL") or env.get("MECHCOMP_BASE_URL", "")
def serve(host: str = "", port: int = 0) -> None:
default_host, default_port = resolve_binding()
host = host or default_host
port = port or default_port
server = ThreadingHTTPServer((host, port), Handler)
print("Mechanical Compiler composer listening on %s:%d" % (host, port))
public = base_url()
if public:
print("Reached through the proxy at %s" % public)
print("Ctrl-C to stop.")
server.serve_forever()
if __name__ == "__main__":
import argparse
ap = argparse.ArgumentParser(description="Serve the composer.")
ap.add_argument("--host", default="",
help="override MECHCOMP_BIND (default: the env file)")
ap.add_argument("--port", type=int, default=0,
help="override MECHCOMP_PORT (default: the env file)")
serve(**vars(ap.parse_args()))
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"""
The renderer and the composer, tested the way a viewer can actually fail.
A picture that looks plausible while being wrong is worse than no picture, and
this is the first part of the system CIVICVS will judge by eye rather than by
test output. So the things asserted here are the ones an eye cannot check: that
the flip is applied exactly once, that holes are not filled in, that a cavity
really is larger than the stock inside it, and that a rejection reaches the
screen as a message rather than a stack trace.
"""
from __future__ import annotations
import re
import pytest
from mechcomp import svg
SQUARE = [[(0.0, 0.0), (10.0, 0.0), (10.0, 10.0), (0.0, 10.0)]]
WITH_HOLE = [
[(0.0, 0.0), (10.0, 0.0), (10.0, 10.0), (0.0, 10.0)],
[(4.0, 4.0), (6.0, 4.0), (6.0, 6.0), (4.0, 6.0)],
]
# ---------------------------------------------------------------------------
# The renderer
# ---------------------------------------------------------------------------
def test_every_ring_reaches_the_path():
"""A hole silently dropped would render as solid material."""
d = svg.path_d(WITH_HOLE)
assert d.count("M ") == 2, d
assert d.count("Z") == 2
assert "4 4" in d.replace(".0", "")
def test_holes_use_evenodd_so_winding_does_not_matter():
"""
Ring winding is not something this module should have to know. evenodd
renders a hole as a hole either way, and its absence is the difference
between a bore and a solid plug.
"""
out = svg.render(WITH_HOLE)
assert out.count('fill-rule="evenodd"') >= 1
def test_degenerate_rings_are_skipped_not_emitted():
assert svg.path_d([[(0.0, 0.0), (1.0, 1.0)]]) == ""
assert svg.path_d([[]]) == ""
def test_the_vertical_flip_is_applied_exactly_once():
"""
Geometry has +Y up, SVG has +Y down. Flipping twice, or not at all, gives a
part that is upside down -- which for an asymmetric profile like T or A
Frame is wrong in a way that is easy to miss and impossible to print
around.
"""
out = svg.render(SQUARE)
assert out.count("scale(1,-1)") == 1
assert len(re.findall(r"transform=", out)) == 1
def test_coordinates_are_left_in_geometry_space():
"""
The flip is in the transform, so the numbers in the file are the geometry's
own and can be read against the report. Negating them instead would make
the file unreadable against anything.
"""
out = svg.render(SQUARE)
assert " 10 " in out or " 10 10" in out
assert "-10" not in svg.path_d(SQUARE)
def test_viewbox_contains_the_geometry_plus_margin():
out = svg.render(SQUARE, margin=3.0)
vb = re.search(r'viewBox="([-\d. ]+)"', out).group(1).split()
x0, y0, w, h = (float(v) for v in vb)
assert x0 == pytest.approx(-3.0)
assert y0 == pytest.approx(-3.0)
assert w == pytest.approx(16.0)
assert h == pytest.approx(16.0)
def test_layers_are_separately_classed():
"""
ROADMAP section 4's stated reason for the port. A flattened silhouette
would not have justified leaving OpenSCAD.
"""
out = svg.render(SQUARE, cavities=WITH_HOLE, stock=[SQUARE[0]])
for cls in ("mc-layer-material", "mc-layer-cavity", "mc-layer-stock"):
assert cls in out, cls
def test_optional_layers_are_omitted_when_absent():
out = svg.render(SQUARE)
assert "mc-layer-material" in out
assert "mc-layer-cavity" not in out
assert "mc-layer-stock" not in out
def test_bounds_of_nothing_does_not_divide_by_zero():
assert svg.bounds([]) == (-1.0, -1.0, 1.0, 1.0)
assert svg.render([]).startswith("<svg")
# ---------------------------------------------------------------------------
# Against real geometry
# ---------------------------------------------------------------------------
def test_a_real_profile_renders_with_all_three_layers():
build = pytest.importorskip("mechcomp.profiles").build
result = build(family="3x", profile="Y", params={})
out = svg.render_result(result)
assert out.startswith("<svg") and out.rstrip().endswith("</svg>")
for cls in ("mc-layer-material", "mc-layer-cavity", "mc-layer-stock"):
assert cls in out, "%s missing from a real render" % cls
assert out.count("scale(1,-1)") == 1
def test_the_cavity_is_drawn_larger_than_the_stock_in_it():
"""
The fit gap is the reason to look at the picture at all. If cavity and stock
render identically, the clearance is invisible and the viewer is useless for
the one judgement it exists to support.
"""
build = pytest.importorskip("mechcomp.profiles").build
from mechcomp.geom.join import cavity_region
from mechcomp.geom.records import strap_path
from mechcomp.geom.region import area as region_area
result = build(family="3x", profile="Y", params={"fit_clearance_mm": 0.4})
cav = cavity_region(result.members, result.geo)
stock = [strap_path(m, result.geo) for m in result.members]
assert region_area(cav) > region_area(stock), (
"cavity is not larger than the stock it holds")
def test_every_profile_in_both_families_renders():
"""A viewer that works for Y and breaks on Cross is not a catalogue."""
profiles = pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import families
for name, family in families().items():
for profile in sorted(family.catalogue):
try:
result = profiles.build(family=name, profile=profile, params={})
except profiles.ProfileRejected:
continue
out = svg.render_result(result)
assert out.startswith("<svg"), "%s/%s" % (name, profile)
assert "mc-layer-material" in out, "%s/%s" % (name, profile)
# ---------------------------------------------------------------------------
# The composer payload
# ---------------------------------------------------------------------------
def test_binding_comes_from_the_deployment_not_from_a_guess(tmp_path,
monkeypatch):
"""
The deployment already declares where this service lives. Inventing a
port put it somewhere nginx does not look and, worse, on every interface
the container has.
"""
from mechcomp.web.app import base_url, resolve_binding
for key in ("MECHCOMP_BIND", "MECHCOMP_PORT", "MECHCOMP_BASE_URL"):
monkeypatch.delenv(key, raising=False)
envf = tmp_path / "mechcomp.env"
envf.write_text(
"# staging\n"
"MECHCOMP_ENV=staging\n"
"MECHCOMP_BIND=10.20.0.10 # scalar; loopback is NOT bound\n"
"MECHCOMP_PORT=8770\n"
"MECHCOMP_BASE_URL=https://mechanical-compiler.dev.infra\n")
assert resolve_binding(str(envf)) == ("10.20.0.10", 8770)
assert base_url(str(envf)) == "https://mechanical-compiler.dev.infra"
def test_a_real_environment_variable_wins_over_the_file(tmp_path, monkeypatch):
from mechcomp.web.app import resolve_binding
envf = tmp_path / "mechcomp.env"
envf.write_text("MECHCOMP_BIND=10.20.0.10\nMECHCOMP_PORT=8770\n")
monkeypatch.setenv("MECHCOMP_PORT", "9001")
monkeypatch.delenv("MECHCOMP_BIND", raising=False)
assert resolve_binding(str(envf)) == ("10.20.0.10", 9001)
def test_the_fallback_is_loopback_never_every_interface(tmp_path, monkeypatch):
"""
Behind a reverse proxy, binding too narrowly fails loudly as a 502 and
binding too widely fails silently as an open service. If this ever
returns 0.0.0.0 by default, the quiet failure is back.
"""
from mechcomp.web.app import resolve_binding
for key in ("MECHCOMP_BIND", "MECHCOMP_PORT"):
monkeypatch.delenv(key, raising=False)
host, port = resolve_binding(str(tmp_path / "absent.env"))
assert host == "127.0.0.1", host
assert host not in ("0.0.0.0", "::", ""), "bound every interface"
assert port == 8770
def test_a_malformed_env_file_does_not_widen_the_binding(tmp_path, monkeypatch):
from mechcomp.web.app import resolve_binding
for key in ("MECHCOMP_BIND", "MECHCOMP_PORT"):
monkeypatch.delenv(key, raising=False)
envf = tmp_path / "mechcomp.env"
envf.write_text("garbage\nMECHCOMP_PORT=not-a-number\n[section]\n")
host, port = resolve_binding(str(envf))
assert host == "127.0.0.1"
assert port == 8770
def test_payload_carries_a_picture_a_report_and_an_identity():
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload
p = build_payload("3x", "Y", {})
assert p["ok"] is True
assert p["svg"].startswith("<svg")
assert p["report"]["PROFILE"] == "Y"
assert p["input_id"], "no design id on the payload"
assert "MECHCOMP DESIGN RECORD" in p["record"]
def test_changing_a_control_changes_the_part_and_its_identity():
"""The composer's whole premise, end to end."""
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload
a = build_payload("3x", "Y", {"fit_clearance_mm": "0.15"})
b = build_payload("3x", "Y", {"fit_clearance_mm": "0.35"})
assert a["ok"] and b["ok"]
assert a["svg"] != b["svg"], "the drawing did not change"
assert a["input_id"] != b["input_id"], "two settings share one design id"
def test_form_strings_are_coerced_to_the_types_the_compiler_expects():
"""Everything arrives from a browser as text; ints must not become floats."""
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload
p = build_payload("3x", "Y", {"bundle_count": "2", "fit_clearance_mm": "0.3"})
assert p["ok"] is True
assert p["values"]["bundle_count"] == 2
assert isinstance(p["values"]["bundle_count"], int)
assert p["values"]["fit_clearance_mm"] == 0.3
def test_a_rejection_is_a_message_not_a_crash():
"""
A rejection is the compiler working. It must read as an explanation on the
screen, and it must still name the parameter and the limit.
"""
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload
p = build_payload("3x", "Y", {"min_wall_mm": "0"})
assert p["ok"] is False
assert p["message"].strip()
assert "trace" not in p
assert "min_wall_mm" in p["message"]
def test_nonsense_input_does_not_take_the_page_down():
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload
p = build_payload("3x", "Y", {"fit_clearance_mm": "banana",
"not_a_parameter": "7"})
assert "ok" in p
assert "not_a_parameter" not in p["values"]
def test_controls_offered_are_relevant_to_the_selected_profile():
"""
Thirty controls of which twenty do nothing is not a composer. Selecting Y
must not present the Three-Fin parameters.
"""
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload
y = build_payload("3x", "Y", {})
offered = {k for _, keys in y["groups"] for k in keys}
assert any(k.startswith("y_") for k in offered)
assert not any(k.startswith("three_fin_") for k in offered), sorted(offered)
assert "strap_width_mm" in offered and "fit_clearance_mm" in offered
def test_every_offered_control_is_a_real_parameter():
"""A control that does nothing is worse than a missing one."""
pytest.importorskip("mechcomp.profiles")
from mechcomp.web.app import build_payload, families
for name, family in families().items():
for profile in sorted(family.catalogue):
p = build_payload(name, profile, {})
for _, keys in p["groups"]:
for key in keys:
assert key in family.defaults, (
"%s/%s offers %s, which is not a parameter"
% (name, profile, key))