feat(workflows): Workflow DX (#5607)

packages/workflows/src/utils/composer/hook.ts

@@ -0,0 +1,43 @@
+import {
+  resolveValue,
+  SymbolMedusaWorkflowComposerContext,
+  SymbolWorkflowHook,
+} from "./helpers"
+import {
+  CreateWorkflowComposerContext,
+  StepExecutionContext,
+  WorkflowData,
+} from "./type"
+
+export function hook<TOutput>(name: string, value: any): WorkflowData<TOutput> {
+  const hookBinder = (
+    global[SymbolMedusaWorkflowComposerContext] as CreateWorkflowComposerContext
+  ).hookBinder
+
+  return hookBinder(name, function (context) {
+    return {
+      __value: async function (transactionContext) {
+        const executionContext: StepExecutionContext = {
+          container: transactionContext.container,
+          metadata: transactionContext.metadata,
+          context: transactionContext.context,
+        }
+
+        const allValues = await resolveValue(value, transactionContext)
+        const stepValue = allValues
+          ? JSON.parse(JSON.stringify(allValues))
+          : allValues
+
+        let finalResult
+        const functions = context.hooksCallback_[name]
+        for (let i = 0; i < functions.length; i++) {
+          const fn = functions[i]
+          const arg = i === 0 ? stepValue : finalResult
+          finalResult = await fn.apply(fn, [arg, executionContext])
+        }
+        return finalResult
+      },
+      __type: SymbolWorkflowHook,
+    }
+  })
+}