feat(pipeline): extract STEP_HANDLERS into dynamic PipelineRegistry

src/pipeline/executor.ts

@@ -4,11 +4,7 @@
 
 import chalk from 'chalk';
 import type { IPage } from '../types.js';
-import { stepNavigate, stepClick, stepType, stepWait, stepPress, stepSnapshot, stepEvaluate } from './steps/browser.js';
-import { stepFetch } from './steps/fetch.js';
-import { stepSelect, stepMap, stepFilter, stepSort, stepLimit } from './steps/transform.js';
-import { stepIntercept } from './steps/intercept.js';
-import { stepTap } from './steps/tap.js';
+import { getStep, type StepHandler } from './registry.js';
 import { log } from '../logger.js';
 
 export interface PipelineContext {
@@ -16,28 +12,6 @@ export interface PipelineContext {
   debug?: boolean;
 }
 
-/** Step handler: all steps conform to (page, params, data, args) => Promise<any> */
-type StepHandler = (page: IPage | null, params: any, data: any, args: Record<string, any>) => Promise<any>;
-
-/** Registry of all available step handlers */
-const STEP_HANDLERS: Record<string, StepHandler> = {
-  navigate: stepNavigate,
-  fetch: stepFetch,
-  select: stepSelect,
-  evaluate: stepEvaluate,
-  snapshot: stepSnapshot,
-  click: stepClick,
-  type: stepType,
-  wait: stepWait,
-  press: stepPress,
-  map: stepMap,
-  filter: stepFilter,
-  sort: stepSort,
-  limit: stepLimit,
-  intercept: stepIntercept,
-  tap: stepTap,
-};
-
 export async function executePipeline(
   page: IPage | null,
   pipeline: any[],
@@ -54,7 +28,7 @@ export async function executePipeline(
     for (const [op, params] of Object.entries(step)) {
       if (debug) debugStepStart(i + 1, total, op, params);
 
-      const handler = STEP_HANDLERS[op];
+      const handler = getStep(op);
       if (handler) {
         data = await handler(page, params, data, args);
       } else {

src/pipeline/registry.ts

@@ -0,0 +1,60 @@
+/**
+ * Dynamic registry for pipeline steps.
+ * Allows core and third-party plugins to register custom YAML operations.
+ */
+
+import type { IPage } from '../types.js';
+
+// Import core steps
+import { stepNavigate, stepClick, stepType, stepWait, stepPress, stepSnapshot, stepEvaluate } from './steps/browser.js';
+import { stepFetch } from './steps/fetch.js';
+import { stepSelect, stepMap, stepFilter, stepSort, stepLimit } from './steps/transform.js';
+import { stepIntercept } from './steps/intercept.js';
+import { stepTap } from './steps/tap.js';
+
+/** 
+ * Step handler: all pipeline steps conform to this generic interface.
+ * TData is the type of the `data` state flowing into the step.
+ * TResult is the expected return type.
+ */
+export type StepHandler<TData = any, TResult = any> = (
+  page: IPage | null,
+  params: any,
+  data: TData,
+  args: Record<string, any>
+) => Promise<TResult>;
+
+const _stepRegistry = new Map<string, StepHandler>();
+
+/**
+ * Get a registered step handler by name.
+ */
+export function getStep(name: string): StepHandler | undefined {
+  return _stepRegistry.get(name);
+}
+
+/**
+ * Register a new custom step handler for the YAML pipeline.
+ */
+export function registerStep(name: string, handler: StepHandler): void {
+  _stepRegistry.set(name, handler);
+}
+
+// -------------------------------------------------------------
+// Auto-Register Core Steps
+// -------------------------------------------------------------
+registerStep('navigate', stepNavigate);
+registerStep('fetch', stepFetch);
+registerStep('select', stepSelect);
+registerStep('evaluate', stepEvaluate);
+registerStep('snapshot', stepSnapshot);
+registerStep('click', stepClick);
+registerStep('type', stepType);
+registerStep('wait', stepWait);
+registerStep('press', stepPress);
+registerStep('map', stepMap);
+registerStep('filter', stepFilter);
+registerStep('sort', stepSort);
+registerStep('limit', stepLimit);
+registerStep('intercept', stepIntercept);
+registerStep('tap', stepTap);