Add support for step functions defined as object properties

[TooTallNate]

Added support for step functions defined as object properties in the SWC plugin.

What changed?

This PR extends the SWC plugin to support step functions defined as object properties. It now handles three different patterns:

1. Arrow functions in object properties: tool({ execute: async () => { "use step"; ... } })
2. Function expressions in object properties: tool({ execute: async function() { "use step"; ... } })
3. Method syntax in objects: tool({ async execute() { "use step"; ... } })

The implementation:

• Detects "use step" directives in object property functions
• Hoists these functions in step mode
• Converts them to step initializer calls in workflow mode
• Properly tracks and registers these functions with appropriate identifiers
• Updates metadata generation to include object property step functions

How to test?

Test with various object property function patterns:

// Arrow function in object property
const weatherTool = tool({
  execute: async ({ location }) => {
    "use step";
    return { location, temperature: 72 };
  }
});

// Function expression in object property
const timeTool = tool({
  execute: async function() {
    "use step";
    return { time: new Date().toISOString() };
  }
});

// Method syntax
const dateTool = tool({
  async execute() {
    "use step";
    return { date: new Date().toDateString() };
  }
});

Why make this change?

This change enables a common pattern in JavaScript where functions are defined as object properties, particularly in AI SDK tool definitions.

Previously, the SWC plugin only supported top-level function declarations and expressions with the "use step" directive. This enhancement provides a more natural developer experience by allowing step functions to be defined directly within their object context.

[changeset-bot]

🦋 Changeset detected

Latest commit: 48ddccb

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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[TooTallNate]

• [swc-plugin-workflow] Fix compiler warnings #348 : 2 dependent PRs (#349 , #350 )
• Add support for defining model as a step function initializer in DurableAgent #346
• Add support for step functions nested inside of workflow functions #345
• Add support for step functions defined as object properties #342 👈 (View in Graphite)
• Use "stepId" instead of Symbol.for("STEP_FUNCTION_NAME_SYMBOL") for annotating step functions #341
• Remove step function identifier transform out of swc-plugin and into useStep() runtime function #337
• Transform step functions to single useStep() calls #336
• main

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