before functional changes by codex

test/basic/constructor.basic.test.js

@@ -0,0 +1,55 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const NodeClass = require('../../src/nodeClass');
+const { Reactor_CSTR, Reactor_PFR } = require('../../src/specificClass');
+const { makeUiConfig, makeReactorConfig, makeNodeStub } = require('../helpers/factories');
+
+test('_loadConfig coerces numeric fields and builds initial state vector', () => {
+  const inst = Object.create(NodeClass.prototype);
+  inst.node = { id: 'n-reactor-1' };
+  inst.name = 'reactor';
+
+  inst._loadConfig(
+    makeUiConfig({
+      volume: '12.5',
+      length: '9',
+      resolution_L: '7',
+      alpha: '0.5',
+      n_inlets: '3',
+      timeStep: '2',
+      S_O_init: '1.1',
+    }),
+  );
+
+  assert.equal(inst.config.volume, 12.5);
+  assert.equal(inst.config.length, 9);
+  assert.equal(inst.config.resolution_L, 7);
+  assert.equal(inst.config.alpha, 0.5);
+  assert.equal(inst.config.n_inlets, 3);
+  assert.equal(inst.config.timeStep, 2);
+  assert.equal(inst.config.initialState.length, 13);
+  assert.equal(inst.config.initialState[0], 1.1);
+});
+
+test('_setupClass selects Reactor_CSTR when configured as CSTR', () => {
+  const inst = Object.create(NodeClass.prototype);
+  inst.node = makeNodeStub();
+  inst.config = makeReactorConfig({ reactor_type: 'CSTR' });
+
+  inst._setupClass();
+
+  assert.ok(inst.source instanceof Reactor_CSTR);
+  assert.equal(inst.node.source, inst.source);
+});
+
+test('_setupClass selects Reactor_PFR when configured as PFR', () => {
+  const inst = Object.create(NodeClass.prototype);
+  inst.node = makeNodeStub();
+  inst.config = makeReactorConfig({ reactor_type: 'PFR', length: 10, resolution_L: 5 });
+
+  inst._setupClass();
+
+  assert.ok(inst.source instanceof Reactor_PFR);
+  assert.equal(inst.node.source, inst.source);
+});