perf(core): avoid intermediate arrays in definition (#61445)

crisbeto · thePunderWoman · commit b785256b9e7f · 2025-05-19T09:20:07.000Z
A minor performance improvement for `ɵɵdefineComponent` where the underlying `extractDefListOrFactory` call had a chain of `.map.filter` which meant that we were unnecessarily creating intermediate arrays just to filter out the null values. These changes switch to simple `for` loop to get around it. PR Close #61445
diff --git a/packages/core/src/render3/definition.ts b/packages/core/src/render3/definition.ts
@@ -28,11 +28,9 @@ import type {
   DependencyTypeList,
   DirectiveDef,
   DirectiveDefFeature,
-  DirectiveDefListOrFactory,
   HostBindingsFunction,
   InputTransformFunction,
   PipeDef,
-  PipeDefListOrFactory,
   TypeOrFactory,
   ViewQueriesFunction,
 } from './interfaces/definition';
@@ -382,8 +380,8 @@ export function ɵɵdefineComponent<T>(
 
     initFeatures(def);
     const dependencies = componentDefinition.dependencies;
-    def.directiveDefs = extractDefListOrFactory(dependencies, /* pipeDef */ false);
-    def.pipeDefs = extractDefListOrFactory(dependencies, /* pipeDef */ true);
+    def.directiveDefs = extractDefListOrFactory(dependencies, extractDirectiveDef);
+    def.pipeDefs = extractDefListOrFactory(dependencies, getPipeDef);
     def.id = getComponentId(def);
 
     return def;
@@ -394,10 +392,6 @@ export function extractDirectiveDef(type: Type<any>): DirectiveDef<any> | Compon
   return getComponentDef(type) || getDirectiveDef(type);
 }
 
-function nonNull<T>(value: T | null): value is T {
-  return value !== null;
-}
-
 /**
  * @codeGenApi
  */
@@ -657,28 +651,27 @@ function initFeatures<T>(definition: DirectiveDef<T> | ComponentDef<T>): void {
   definition.features?.forEach((fn) => fn(definition));
 }
 
-export function extractDefListOrFactory(
-  dependencies: TypeOrFactory<DependencyTypeList> | undefined,
-  pipeDef: false,
-): DirectiveDefListOrFactory | null;
-export function extractDefListOrFactory(
-  dependencies: TypeOrFactory<DependencyTypeList> | undefined,
-  pipeDef: true,
-): PipeDefListOrFactory | null;
-export function extractDefListOrFactory(
+export function extractDefListOrFactory<T>(
   dependencies: TypeOrFactory<DependencyTypeList> | undefined,
-  pipeDef: boolean,
-): unknown {
+  defExtractor: (type: Type<unknown>) => T | null,
+): (() => T[]) | T[] | null {
   if (!dependencies) {
     return null;
   }
 
-  const defExtractor = pipeDef ? getPipeDef : extractDirectiveDef;
+  return () => {
+    const resolvedDependencies = typeof dependencies === 'function' ? dependencies() : dependencies;
+    const result: T[] = [];
 
-  return () =>
-    (typeof dependencies === 'function' ? dependencies() : dependencies)
-      .map((dep) => defExtractor(dep))
-      .filter(nonNull);
+    for (const dep of resolvedDependencies) {
+      const definition = defExtractor(dep);
+      if (definition !== null) {
+        result.push(definition);
+      }
+    }
+
+    return result;
+  };
 }
 
 /**
diff --git a/packages/core/src/render3/scope.ts b/packages/core/src/render3/scope.ts
@@ -11,9 +11,9 @@ import {Type} from '../interface/type';
 import {flatten} from '../util/array_utils';
 import {noSideEffects} from '../util/closure';
 import {EMPTY_ARRAY} from '../util/empty';
-import {getNgModuleDefOrThrow} from './def_getters';
+import {getNgModuleDefOrThrow, getPipeDef} from './def_getters';
 
-import {extractDefListOrFactory} from './definition';
+import {extractDefListOrFactory, extractDirectiveDef} from './definition';
 import {depsTracker} from './deps_tracker/deps_tracker';
 import {
   ComponentDef,
@@ -38,8 +38,8 @@ export function ɵɵsetComponentScope(
   pipes: Type<any>[] | (() => Type<any>[]),
 ): void {
   const def = type.ɵcmp as ComponentDef<any>;
-  def.directiveDefs = extractDefListOrFactory(directives, /* pipeDef */ false);
-  def.pipeDefs = extractDefListOrFactory(pipes, /* pipeDef */ true);
+  def.directiveDefs = extractDefListOrFactory(directives, extractDirectiveDef);
+  def.pipeDefs = extractDefListOrFactory(pipes, getPipeDef);
 }
 
 /**
diff --git a/packages/core/test/bundling/animations-standalone/bundle.golden_symbols.json b/packages/core/test/bundling/animations-standalone/bundle.golden_symbols.json
@@ -410,7 +410,6 @@
   "nextNgElementId",
   "ngOnChangesSetInput",
   "ngZoneInstanceId",
-  "nonNull",
   "noop",
   "noop2",
   "normalizeAnimationEntry",
diff --git a/packages/core/test/bundling/defer/bundle.golden_symbols.json b/packages/core/test/bundling/defer/bundle.golden_symbols.json
@@ -420,7 +420,6 @@
   "nextNgElementId",
   "ngOnChangesSetInput",
   "ngZoneInstanceId",
-  "nonNull",
   "noop",
   "noop2",
   "notFoundValueOrThrow",
diff --git a/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json b/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json
@@ -527,7 +527,6 @@
   "ngOnChangesSetInput",
   "ngZoneInstanceId",
   "noSideEffects",
-  "nonNull",
   "noop",
   "noop2",
   "normalizeValidators",
diff --git a/packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json b/packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json
@@ -517,7 +517,6 @@
   "ngOnChangesSetInput",
   "ngZoneInstanceId",
   "noSideEffects",
-  "nonNull",
   "noop",
   "noop2",
   "normalizeValidators",
diff --git a/packages/core/test/bundling/hydration/bundle.golden_symbols.json b/packages/core/test/bundling/hydration/bundle.golden_symbols.json
@@ -378,7 +378,6 @@
   "nextNgElementId",
   "ngOnChangesSetInput",
   "ngZoneInstanceId",
-  "nonNull",
   "noop",
   "noop2",
   "notFoundValueOrThrow",
diff --git a/packages/core/test/bundling/router/bundle.golden_symbols.json b/packages/core/test/bundling/router/bundle.golden_symbols.json
@@ -608,7 +608,6 @@
   "noMatch2",
   "noSideEffects",
   "nodeChildrenAsMap",
-  "nonNull",
   "noop",
   "noop2",
   "normalizeQueryParams",
diff --git a/packages/core/test/bundling/standalone_bootstrap/bundle.golden_symbols.json b/packages/core/test/bundling/standalone_bootstrap/bundle.golden_symbols.json
@@ -316,7 +316,6 @@
   "nextNgElementId",
   "ngOnChangesSetInput",
   "ngZoneInstanceId",
-  "nonNull",
   "noop",
   "noop2",
   "notFoundValueOrThrow",
