refactor(core): Split consumerBefore/AfterComputation (#62549)

This makes it possible to batch effects, where we can "reopen" consumers
during initial render and then finalize them after we are finally done
adding all the effects to a batch:

```
function createBatch() {
  const effect = // ... create effect node
  resetConsumerBeforeComputation(effect);
  return effect;
}

// pseudo-code
function appendEffect(effectBatch, updater) {
  if (value is a signal) {
    const prevConsumer = setActiveConsumer(effectBatch.node);
    const output = value();
    setActiveConsumer(prevConsumer);
    effectBatch.push({ signal, updater });
    return output;
  }
}

function finalizeBatch(effectBatch) {
  if (effectBatch.length > 0) {
    finalizeConsumerAfterComputation(effectBatch.node);
  }
}

const effectBatch = createBatchEffectNode();
appendEffect(signal1, (newValue) => /* something */);
appendEffect(signal2, (newValue) => /* something different */);
finalizeBatch(effectBatch);
```

PR Close #62549

goldens/public-api/core/primitives/signals/index.api.md

@@ -66,6 +66,9 @@ export function createWatch(fn: (onCleanup: WatchCleanupRegisterFn) => void, sch
 // @public
 export function defaultEquals<T>(a: T, b: T): boolean;
 
+// @public
+export function finalizeConsumerAfterComputation(node: ReactiveNode): void;
+
 // @public (undocumented)
 export function getActiveConsumer(): ReactiveNode | null;
 
@@ -151,6 +154,9 @@ export interface ReactiveNode {
     version: Version;
 }
 
+// @public
+export function resetConsumerBeforeComputation(node: ReactiveNode): void;
+
 // @public (undocumented)
 export function runEffect(node: BaseEffectNode): void;
 

packages/core/primitives/signals/index.ts

@@ -28,6 +28,7 @@ export {
   consumerDestroy,
   consumerMarkDirty,
   consumerPollProducersForChange,
+  finalizeConsumerAfterComputation,
   getActiveConsumer,
   isInNotificationPhase,
   isReactive,
@@ -37,6 +38,7 @@ export {
   producerNotifyConsumers,
   producerUpdateValueVersion,
   producerUpdatesAllowed,
+  resetConsumerBeforeComputation,
   runPostProducerCreatedFn,
   setActiveConsumer,
   setPostProducerCreatedFn,

packages/core/primitives/signals/src/graph.ts

@@ -359,21 +359,34 @@ export function producerMarkClean(node: ReactiveNode): void {
 }
 
 /**
- * Prepare this consumer to run a computation in its reactive context.
+ * Prepare this consumer to run a computation in its reactive context and set
+ * it as the active consumer.
  *
  * Must be called by subclasses which represent reactive computations, before those computations
  * begin.
  */
 export function consumerBeforeComputation(node: ReactiveNode | null): ReactiveNode | null {
-  if (node) {
-    node.producersTail = undefined;
-    node.recomputing = true;
-  }
+  if (node) resetConsumerBeforeComputation(node);
+
   return setActiveConsumer(node);
 }
 
 /**
- * Finalize this consumer's state after a reactive computation has run.
+ * Prepare this consumer to run a computation in its reactive context.
+ *
+ * We expose this mainly for code where we manually batch effects into a single
+ * consumer. In those cases we may wish to "reopen" a consumer multiple times
+ * in initial render before finalizing it. Most code should just call
+ * `consumerBeforeComputation` instead of calling this directly.
+ */
+export function resetConsumerBeforeComputation(node: ReactiveNode): void {
+  node.producersTail = undefined;
+  node.recomputing = true;
+}
+
+/**
+ * Finalize this consumer's state and set previous consumer as the active consumer after a
+ * reactive computation has run.
  *
  * Must be called by subclasses which represent reactive computations, after those computations
  * have finished.
@@ -384,10 +397,18 @@ export function consumerAfterComputation(
 ): void {
   setActiveConsumer(prevConsumer);
 
-  if (!node) {
-    return;
-  }
+  if (node) finalizeConsumerAfterComputation(node);
+}
 
+/**
+ * Finalize this consumer's state after a reactive computation has run.
+ *
+ * We expose this mainly for code where we manually batch effects into a single
+ * consumer. In those cases we may wish to "reopen" a consumer multiple times
+ * in initial render before finalizing it. Most code should just call
+ * `consumerAfterComputation` instead of calling this directly.
+ */
+export function finalizeConsumerAfterComputation(node: ReactiveNode): void {
   node.recomputing = false;
 
   // We've finished incrementally rebuilding the producers list, now if there are any producers

packages/core/test/bundling/animations-standalone/bundle.golden_symbols.json

@@ -549,6 +549,7 @@
       "extractDirectiveDef",
       "extractStyleParams",
       "filterNonAnimatableStyles",
+      "finalizeConsumerAfterComputation",
       "findAttrIndexInNode",
       "findDirectiveDefMatches",
       "flattenGroupPlayers",
@@ -850,6 +851,7 @@
       "replacePostStylesAsPre",
       "reportUnhandledError",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveDirectives",
       "resolveElementFromTarget",

packages/core/test/bundling/defer/bundle.golden_symbols.json

@@ -468,6 +468,7 @@
       "extractAttrsAndClassesFromSelector",
       "extractDefListOrFactory",
       "extractDirectiveDef",
+      "finalizeConsumerAfterComputation",
       "findAttrIndexInNode",
       "findDirectiveDefMatches",
       "findMatchingDehydratedViewForDeferBlock",
@@ -722,6 +723,7 @@
       "renderView",
       "reportUnhandledError",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveDirectives",
       "resolveForwardRef",

packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json

@@ -605,6 +605,7 @@
       "extractDefListOrFactory",
       "extractDirectiveDef",
       "fillProperties",
+      "finalizeConsumerAfterComputation",
       "findAttrIndexInNode",
       "findDirectiveDefMatches",
       "findExistingListener",
@@ -982,6 +983,7 @@
       "requiredTrueValidator",
       "requiredValidator",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveComponentResources",
       "resolveDirectives",

packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json

@@ -604,6 +604,7 @@
       "extractDefListOrFactory",
       "extractDirectiveDef",
       "fillProperties",
+      "finalizeConsumerAfterComputation",
       "findAttrIndexInNode",
       "findDirectiveDefMatches",
       "findExistingListener",
@@ -975,6 +976,7 @@
       "reportUnhandledError",
       "requiredValidator",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveComponentResources",
       "resolveDirectives",

packages/core/test/bundling/hydration/bundle.golden_symbols.json

@@ -485,6 +485,7 @@
       "extractAttrsAndClassesFromSelector",
       "extractDefListOrFactory",
       "extractDirectiveDef",
+      "finalizeConsumerAfterComputation",
       "findAndReconcileMatchingDehydratedViewsImpl",
       "findMatchingDehydratedView",
       "findMatchingDehydratedViewImpl",
@@ -764,6 +765,7 @@
       "renderView",
       "reportUnhandledError",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveDirectives",
       "resolveForwardRef",

packages/core/test/bundling/router/bundle.golden_symbols.json

@@ -719,6 +719,7 @@
       "extractDirectiveDef",
       "filter",
       "finalize",
+      "finalizeConsumerAfterComputation",
       "findAttrIndexInNode",
       "findDirectiveDefMatches",
       "findExistingListener",
@@ -1116,6 +1117,7 @@
       "replaceSegment",
       "reportUnhandledError",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveData",
       "resolveDirectives",

packages/core/test/bundling/standalone_bootstrap/bundle.golden_symbols.json

@@ -399,6 +399,7 @@
       "extractAttrsAndClassesFromSelector",
       "extractDefListOrFactory",
       "extractDirectiveDef",
+      "finalizeConsumerAfterComputation",
       "forEachSingleProvider",
       "forkInnerZoneWithAngularBehavior",
       "formatErrorMessage",
@@ -616,6 +617,7 @@
       "renderView",
       "reportUnhandledError",
       "requiresRefreshOrTraversal",
+      "resetConsumerBeforeComputation",
       "resetPreOrderHookFlags",
       "resolveDirectives",
       "resolveForwardRef",