no-direct-variable-mutation-in-workflow - ESLint plugin rules

This rule disallows mutating or recomputing variables directly inside a createWorkflow constructor or a when().then() callback.

Severity#

error. This rule is enabled in the recommended preset.

What it Targets#

This rule targets files in your project's src/workflows directory. It reports assignments, increments, arithmetic, and template literals that use placeholder values directly in a workflow's constructor or in a when().then() callback.

The following code is reported by the rule:

src/workflows/example.ts
1import {2  createWorkflow,3  createStep,4  WorkflowResponse,5} from "@medusajs/framework/workflows-sdk"6
7createWorkflow("my-workflow", (input) => {8  const message1 = step1(input)9  const message2 = step2(input)10  const combined = `${message1} ${message2}`11  return new WorkflowResponse(combined)12})

Instead, derive new values inside transform:

src/workflows/example.ts
1import {2  createWorkflow,3  transform,4} from "@medusajs/framework/workflows-sdk"5
6createWorkflow("my-workflow", (input) => {7  const message1 = step1(input)8  const message2 = step2(input)9  const combined = transform({10    message1, message2,11  }, ({ message1, message2 }) => {12    return `${message1} ${message2}`13  })14
15  return new WorkflowResponse(combined)16})

Why it's Important#

A workflow's constructor and when().then() callbacks run at definition time, not execution time. So, locals like step outputs and input are placeholders, not real values. Mutating or recomputing them doesn't work as expected. Use transform to derive new values.

Learn more in the Workflows documentation.

Fixable#

This rule isn't auto-fixable.