FE-514: Add SymPy → JavaScript compilation pipeline via Pyodide

libs/@hashintel/petrinaut/package.json

@@ -51,6 +51,7 @@
     "d3-scale": "4.0.2",
     "elkjs": "0.11.0",
     "monaco-editor": "0.55.1",
+    "pyodide": "0.27.7",
     "react-icons": "5.5.0",
     "react-resizable-panels": "4.6.5",
     "typescript": "5.9.3",

libs/@hashintel/petrinaut/src/simulation/simulator/build-simulation.test.ts

@@ -1,10 +1,31 @@
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 
 import { buildSimulation } from "./build-simulation";
 import type { SimulationInput } from "./types";
 
+// Mock the SymPy compilation to return simple passthrough functions.
+// This lets us test buildSimulation's validation and buffer logic
+// without requiring a real Pyodide instance.
+vi.mock("./compile-via-sympy", () => ({
+  compileDifferentialEquationViaSymPy: vi.fn().mockResolvedValue(
+    // Returns a no-op dynamics function
+    () => [],
+  ),
+  compileLambdaViaSymPy: vi.fn().mockResolvedValue(
+    // Returns a constant rate
+    () => 1.0,
+  ),
+  compileTransitionKernelViaSymPy: vi.fn().mockResolvedValue(
+    // Returns empty kernel output
+    () => ({}),
+  ),
+}));
+
+// Create a mock PyodideInterface
+const mockPyodide = {} as Parameters<typeof buildSimulation>[1];
+
 describe("buildSimulation", () => {
-  it("builds a simulation with a single place and initial tokens", () => {
+  it("builds a simulation with a single place and initial tokens", async () => {
     const input: SimulationInput = {
       sdcpn: {
         types: [
@@ -56,7 +77,7 @@ describe("buildSimulation", () => {
       maxTime: null,
     };
 
-    const simulationInstance = buildSimulation(input);
+    const simulationInstance = await buildSimulation(input, mockPyodide);
     const frame = simulationInstance.frames[0]!;
 
     // Verify simulation instance properties
@@ -88,7 +109,7 @@ describe("buildSimulation", () => {
     expect(simulationInstance.differentialEquationFns.has("p1")).toBe(true);
   });
 
-  it("builds a simulation with multiple places, transitions, and proper buffer layout", () => {
+  it("builds a simulation with multiple places, transitions, and proper buffer layout", async () => {
     const input: SimulationInput = {
       sdcpn: {
         types: [
@@ -204,7 +225,7 @@ describe("buildSimulation", () => {
       maxTime: null,
     };
 
-    const simulationInstance = buildSimulation(input);
+    const simulationInstance = await buildSimulation(input, mockPyodide);
     const frame = simulationInstance.frames[0]!;
 
     // Verify simulation instance properties
@@ -266,7 +287,7 @@ describe("buildSimulation", () => {
     expect(typeof kernelFn).toBe("function");
   });
 
-  it("throws error when initialMarking references non-existent place", () => {
+  it("throws error when initialMarking references non-existent place", async () => {
     const input: SimulationInput = {
       sdcpn: {
         types: [
@@ -315,12 +336,12 @@ describe("buildSimulation", () => {
       maxTime: null,
     };
 
-    expect(() => buildSimulation(input)).toThrow(
+    await expect(buildSimulation(input, mockPyodide)).rejects.toThrow(
       "Place with ID p_nonexistent in initialMarking does not exist in SDCPN",
     );
   });
 
-  it("throws error when token dimensions don't match place dimensions", () => {
+  it("throws error when token dimensions don't match place dimensions", async () => {
     const input: SimulationInput = {
       sdcpn: {
         types: [
@@ -372,7 +393,7 @@ describe("buildSimulation", () => {
       maxTime: null,
     };
 
-    expect(() => buildSimulation(input)).toThrow(
+    await expect(buildSimulation(input, mockPyodide)).rejects.toThrow(
       "Token dimension mismatch for place p1. Expected 4 values (2 dimensions × 2 tokens), got 3",
     );
   });

libs/@hashintel/petrinaut/src/simulation/simulator/build-simulation.ts

@@ -1,13 +1,18 @@
+import type { PyodideInterface } from "pyodide";
+
 import { SDCPNItemError } from "../../core/errors";
 import {
   deriveDefaultParameterValues,
   mergeParameterValues,
 } from "../../hooks/use-default-parameter-values";
-import { compileUserCode } from "./compile-user-code";
+import {
+  compileDifferentialEquationViaSymPy,
+  compileLambdaViaSymPy,
+  compileTransitionKernelViaSymPy,
+} from "./compile-via-sympy";
 import type {
   DifferentialEquationFn,
   LambdaFn,
-  ParameterValues,
   SimulationFrame,
   SimulationInput,
   SimulationInstance,
@@ -49,12 +54,16 @@ function getPlaceDimensions(
  * - All places and transitions initialized with proper state
  *
  * @param input - The simulation input configuration
+ * @param pyodide - Initialized Pyodide instance with SymPy
  * @returns The initial simulation frame ready for execution
  * @throws {Error} if place IDs in initialMarking don't match places in SDCPN
  * @throws {Error} if token dimensions don't match place dimensions
  * @throws {Error} if user code fails to compile
  */
-export function buildSimulation(input: SimulationInput): SimulationInstance {
+export async function buildSimulation(
+  input: SimulationInput,
+  pyodide: PyodideInterface,
+): Promise<SimulationInstance> {
   const {
     sdcpn,
     initialMarking,
@@ -100,7 +109,7 @@ export function buildSimulation(input: SimulationInput): SimulationInstance {
     }
   }
 
-  // Compile all differential equation functions
+  // Compile all differential equation functions via SymPy
   const differentialEquationFns = new Map<string, DifferentialEquationFn>();
   for (const place of sdcpn.places) {
     // Skip places without dynamics enabled or without differential equation code
@@ -119,9 +128,11 @@ export function buildSimulation(input: SimulationInput): SimulationInstance {
     const { code } = differentialEquation;
 
     try {
-      const fn = compileUserCode<[Record<string, number>[], ParameterValues]>(
+      const fn = await compileDifferentialEquationViaSymPy(
         code,
-        "Dynamics",
+        sdcpn,
+        place.colorId!,
+        pyodide,
       );
       differentialEquationFns.set(place.id, fn as DifferentialEquationFn);
     } catch (error) {
@@ -134,13 +145,16 @@ export function buildSimulation(input: SimulationInput): SimulationInstance {
     }
   }
 
-  // Compile all lambda functions
+  // Compile all lambda functions via SymPy
   const lambdaFns = new Map<string, LambdaFn>();
   for (const transition of sdcpn.transitions) {
     try {
-      const fn = compileUserCode<
-        [Record<string, Record<string, number>[]>, ParameterValues]
-      >(transition.lambdaCode, "Lambda");
+      const fn = await compileLambdaViaSymPy(
+        transition.lambdaCode,
+        sdcpn,
+        transition,
+        pyodide,
+      );
       lambdaFns.set(transition.id, fn as LambdaFn);
     } catch (error) {
       throw new SDCPNItemError(
@@ -173,9 +187,12 @@ export function buildSimulation(input: SimulationInput): SimulationInstance {
     }
 
     try {
-      const fn = compileUserCode<
-        [Record<string, Record<string, number>[]>, ParameterValues]
-      >(transition.transitionKernelCode, "TransitionKernel");
+      const fn = await compileTransitionKernelViaSymPy(
+        transition.transitionKernelCode,
+        sdcpn,
+        transition,
+        pyodide,
+      );
       transitionKernelFns.set(transition.id, fn as TransitionKernelFn);
     } catch (error) {
       throw new SDCPNItemError(