fix: lazy-load esbuild via createRequire (jsdom-safe engine import) + lint cleanup of dead helpers

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/core/src/task-fields.ts

@@ -24,7 +24,6 @@
 
 import type {
   WorkflowFieldDefinition,
-  WorkflowFieldType,
 } from "./workflow-ir-types.js";
 
 // ---------------------------------------------------------------------------
@@ -187,7 +186,6 @@ function validateValue(
         return reject("type-mismatch", `field '${field.id}' (url) expects a string, got ${typeof value}`);
       }
       try {
-        // eslint-disable-next-line no-new
         new URL(value);
       } catch {
         return reject("type-mismatch", `field '${field.id}' value '${value}' is not a valid URL`);
@@ -299,11 +297,6 @@ export function applyFieldDefaults(
 // Reconciliation on workflow edit / switch
 // ---------------------------------------------------------------------------
 
-/** Two field types are "enum-kind" siblings (enum / multi-enum). */
-function isEnumKind(type: WorkflowFieldType): boolean {
-  return type === "enum" || type === "multi-enum";
-}
-
 /**
  * A stored value for `field` is type-compatible with a new field definition iff
  * the new value re-validates cleanly. For enum-kind fields, compatibility also

packages/dashboard/app/components/TaskFieldsSection.tsx

@@ -60,14 +60,6 @@ export interface TaskFieldsSectionProps {
   readOnly?: boolean;
 }
 
-function optionLabel(field: WorkflowFieldDefinition, value: string): string {
-  return field.options?.find((o) => o.value === value)?.label ?? value;
-}
-
-function optionColor(field: WorkflowFieldDefinition, value: string): string | undefined {
-  return field.options?.find((o) => o.value === value)?.color;
-}
-
 /** Resolve the effective widget for a field, applying the per-type default. */
 function resolveWidget(field: WorkflowFieldDefinition): NonNullable<WorkflowFieldDefinition["render"]>["widget"] {
   const explicit = field.render?.widget;

packages/engine/src/code-node-runner.ts

@@ -39,11 +39,23 @@
  */
 
 import { execFile } from "node:child_process";
+import { createRequire } from "node:module";
 import { mkdtemp, rm, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 
-import { transformSync } from "esbuild";
+// esbuild is loaded lazily at first compile: a top-level import would run its
+// environment invariant check (TextEncoder) at module-load time in any process
+// that merely imports @fusion/engine — including jsdom test environments where
+// that invariant fails. Lazy loading confines esbuild to actual code-node use.
+let cachedTransformSync: typeof import("esbuild").transformSync | undefined;
+function getTransformSync(): typeof import("esbuild").transformSync {
+  if (!cachedTransformSync) {
+    const req = createRequire(import.meta.url);
+    cachedTransformSync = (req("esbuild") as typeof import("esbuild")).transformSync;
+  }
+  return cachedTransformSync;
+}
 import type { CustomFieldRejection, TaskDetail, WorkflowIrNode } from "@fusion/core";
 
 import type { WorkflowNodeResult } from "./workflow-graph-executor.js";
@@ -148,7 +160,7 @@ export async function compileCodeNodeSource(source: string): Promise<string> {
     // `transformSync` runs a short-lived per-call child that exits cleanly,
     // avoiding esbuild's long-lived service process (which the test harness's
     // subprocess guard would otherwise flag as a lingering child).
-    const out = transformSync(source, {
+    const out = getTransformSync()(source, {
       loader: "ts",
       format: "esm",
       target: "node18",