Remove step function transformation in client mode

[Copilot]

The SWC compiler was transforming step functions in client mode to call runStep(), a stubbed function that throws errors. This prevented direct step function calls outside workflows, contradicting the documented behavior.

Changes

• SWC transform (packages/swc-plugin-workflow/transform/src/lib.rs)

  • Step functions in TransformMode::Client now only have their directive removed, preserving the original function body
  • Removed client-mode import generation for runStep
  • Cleaned up three unused transformation helper functions

• Fixture tests

  • Updated all output-client.js files via UPDATE=1 to reflect unchanged step implementations

• New E2E test

Before

// Client mode output
import { runStep as __private_run_step } from "workflow/api";
export async function processData(data) {
    return __private_run_step("processData", { arguments: [data] });
}

After

// Client mode output - directive removed, implementation intact
export async function processData(data) {
    const result = someHelper(data);
    const transformed = anotherHelper(result);
    return defaultExport(transformed);
}

Original prompt

in the SWC compiler right now,I think we transform the step function definitions in “client mode” to use “runStep” from “workflow/internal/private” but that function is just stubbed to throw an error. in reality we shouldn’t transform the step function in client mode. this way, calling steps directly outside of a workflow will also "just work" like its meant to (and as we say in the docs)

Let's change the compiler to not transform the step in client mode (it should just remove the directive) and update the fixture tests (using UPDATE=1 when rynning them). Additionally, add a test to the core package that ensures that calling a step outside a workflow works as expected :)

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[changeset-bot]

🦋 Changeset detected

Latest commit: f19e847

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 10 packages

Name	Type
@workflow/swc-plugin	Patch
@workflow/builders	Patch
@workflow/cli	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/sveltekit	Patch
workflow	Patch
@workflow/world-testing	Patch
@workflow/nuxt	Patch
@workflow/ai	Patch

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Project	Deployment	Preview	Comments	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview	Comment	Nov 8, 2025 3:05am
example-nextjs-workflow-webpack	Ready	Preview	Comment	Nov 8, 2025 3:05am
example-workflow	Ready	Preview	Comment	Nov 8, 2025 3:05am
workbench-nitro-workflow	Ready	Preview	Comment	Nov 8, 2025 3:05am
workbench-nuxt-workflow	Ready	Preview	Comment	Nov 8, 2025 3:05am
workbench-sveltekit-workflow	Ready	Preview	Comment	Nov 8, 2025 3:05am
workbench-vite-workflow	Ready	Preview	Comment	Nov 8, 2025 3:05am
workflow-docs	Ready	Preview	Comment	Nov 8, 2025 3:05am

[VaguelySerious]

LGTM - I see the API endpoint isn't being added to to Hono / Nitro v1/v2, but I guess that's fine since we don't run e2e tests against them yet