From d2835926b3a2db5632b743f951224691d51e8e1a Mon Sep 17 00:00:00 2001
From: Nathan Colosimo <110621881+NathanColosimo@users.noreply.github.com>
Date: Mon, 22 Jun 2026 14:26:33 -0700
Subject: [PATCH 1/2] test(nitro): reproduce stale steps after HMR

---
 packages/core/e2e/dev.test.ts | 63 +++++++++++++++++++++++++++++++++--
 1 file changed, 61 insertions(+), 2 deletions(-)

diff --git a/packages/core/e2e/dev.test.ts b/packages/core/e2e/dev.test.ts
index f4750d67cf..a10fcc1c14 100644
--- a/packages/core/e2e/dev.test.ts
+++ b/packages/core/e2e/dev.test.ts
@@ -1,7 +1,8 @@
 import fs from 'node:fs/promises';
 import path from 'node:path';
-import { afterEach, beforeAll, describe, expect, test } from 'vitest';
-import { getWorkbenchAppPath } from './utils';
+import { afterEach, assert, beforeAll, describe, expect, test } from 'vitest';
+import { start } from '../src/runtime';
+import { getWorkbenchAppPath, getWorkflowMetadata, setupWorld } from './utils';
 
 export interface DevTestConfig {
   generatedStepPath: string;
@@ -259,6 +260,64 @@ export async function myNewStep() {
       });
     });
 
+    test.runIf(process.env.APP_NAME === 'vite')(
+      'should execute updated step logic after HMR',
+      { timeout: 70_000 },
+      async () => {
+        assert(deploymentUrl);
+        setupWorld(deploymentUrl);
+
+        const workflowFile = path.join(appPath, workflowsDir, testWorkflowFile);
+        const content = await fs.readFile(workflowFile, 'utf8');
+        const before = 'before HMR';
+        const after = 'after HMR';
+        const fixture = `
+export async function hmrWorkflow() {
+  'use workflow';
+  return hmrStep();
+}
+
+async function hmrStep() {
+  'use step';
+  return '${before}';
+}
+`;
+
+        await fs.writeFile(workflowFile, content + fixture);
+        restoreFiles.push({ path: workflowFile, content });
+
+        await pollUntil({
+          description: 'generated step output to include the HMR fixture',
+          check: async () => {
+            expect(await fs.readFile(generatedStep, 'utf8')).toContain(before);
+          },
+        });
+
+        const workflow = await getWorkflowMetadata(
+          deploymentUrl,
+          `workflows/${testWorkflowFile}`,
+          'hmrWorkflow'
+        );
+        const runBefore = await start<[], string>(workflow, []);
+        expect(await runBefore.returnValue).toBe(before);
+
+        await fs.writeFile(
+          workflowFile,
+          (content + fixture).replace(before, after)
+        );
+
+        await pollUntil({
+          description: 'generated step output to include the HMR update',
+          check: async () => {
+            expect(await fs.readFile(generatedStep, 'utf8')).toContain(after);
+          },
+        });
+
+        const runAfter = await start<[], string>(workflow, []);
+        expect(await runAfter.returnValue).toBe(after);
+      }
+    );
+
     test(
       'should rebuild on adding workflow file',
       { timeout: 60_000 },

From 401c7f9bfccb529ae8fd91804682231d6b63a14b Mon Sep 17 00:00:00 2001
From: Nathan Colosimo <110621881+NathanColosimo@users.noreply.github.com>
Date: Mon, 22 Jun 2026 14:30:21 -0700
Subject: [PATCH 2/2] fix(nitro): reload steps during Vite HMR

---
 .changeset/fresh-steps-hmr.md |  5 +++++
 packages/nitro/src/index.ts   | 19 +++++++++++++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/fresh-steps-hmr.md

diff --git a/.changeset/fresh-steps-hmr.md b/.changeset/fresh-steps-hmr.md
new file mode 100644
index 0000000000..88dfa8248e
--- /dev/null
+++ b/.changeset/fresh-steps-hmr.md
@@ -0,0 +1,5 @@
+---
+'@workflow/nitro': patch
+---
+
+Reload rebuilt step bundles during Vite development.
diff --git a/packages/nitro/src/index.ts b/packages/nitro/src/index.ts
index 0b738c9bb0..b068240dbf 100644
--- a/packages/nitro/src/index.ts
+++ b/packages/nitro/src/index.ts
@@ -1,5 +1,5 @@
-import { createRequire } from 'node:module';
 import { mkdirSync, readFileSync, writeFileSync } from 'node:fs';
+import { createRequire } from 'node:module';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 import { WORKFLOW_QUEUE_TRIGGER } from '@workflow/builders';
 import { workflowTransformPlugin } from '@workflow/rollup';
@@ -413,7 +413,13 @@ function addDashboardHandler(nitro: Nitro) {
   }
 }
 
-function addVirtualHandler(nitro: Nitro, route: string, buildPath: string) {
+type VirtualHandlerPath = 'workflow/webhook.mjs' | 'workflow/workflows.mjs';
+
+function addVirtualHandler(
+  nitro: Nitro,
+  route: string,
+  buildPath: VirtualHandlerPath
+) {
   nitro.options.handlers.push({
     route,
     handler: `#${buildPath}`,
@@ -421,6 +427,13 @@ function addVirtualHandler(nitro: Nitro, route: string, buildPath: string) {
   const handlerImportPath = JSON.stringify(
     join(nitro.options.buildDir, buildPath)
   );
+  const stepsImportPath = JSON.stringify(
+    join(nitro.options.buildDir, 'workflow/steps.mjs')
+  );
+  const preloadSteps: Record<VirtualHandlerPath, string> = {
+    'workflow/webhook.mjs': '',
+    'workflow/workflows.mjs': `await import(/* @vite-ignore */ pathToFileURL(${stepsImportPath}).href + "?t=" + version);`,
+  };
 
   if (nitro.options.dev) {
     // Dev mode: load generated workflow bundles from disk at request time.
@@ -442,6 +455,7 @@ function addVirtualHandler(nitro: Nitro, route: string, buildPath: string) {
         if (version !== currentVersion) {
           currentVersion = version;
           currentImportPath = pathToFileURL(handlerPath).href + "?t=" + version;
+          ${preloadSteps[buildPath]}
         }
         return (await import(currentImportPath)).POST;
       }
@@ -465,6 +479,7 @@ function addVirtualHandler(nitro: Nitro, route: string, buildPath: string) {
         if (version !== currentVersion) {
           currentVersion = version;
           currentImportPath = pathToFileURL(handlerPath).href + "?t=" + version;
+          ${preloadSteps[buildPath]}
         }
         return (await import(currentImportPath)).POST;
       }