fix(ngcc): handle new __spreadArrays tslib helper (#33617)

We already have special cases for the `__spread` helper function and with this change we handle the new tslib helper introduced in version 1.10 `__spreadArrays`.

For more context see: https://github.com/microsoft/tslib/releases/tag/1.10.0

Fixes: #33614

PR Close #33617

packages/compiler-cli/src/ngtsc/partial_evaluator/src/ts_helpers.ts

@@ -15,10 +15,12 @@ import {ResolvedValue, ResolvedValueArray} from './result';
 
 export function evaluateTsHelperInline(
     helper: TsHelperFn, node: ts.Node, args: ResolvedValueArray): ResolvedValue {
-  if (helper === TsHelperFn.Spread) {
-    return evaluateTsSpreadHelper(node, args);
-  } else {
-    throw new Error(`Cannot evaluate unknown helper ${helper} inline`);
+  switch (helper) {
+    case TsHelperFn.Spread:
+    case TsHelperFn.SpreadArrays:
+      return evaluateTsSpreadHelper(node, args);
+    default:
+      throw new Error(`Cannot evaluate unknown helper ${helper} inline`);
   }
 }
 

packages/compiler-cli/src/ngtsc/partial_evaluator/test/evaluator_spec.ts

@@ -514,7 +514,28 @@ runInEachFileSystem(() => {
             {
               name: _('/node_modules/tslib/index.d.ts'),
               contents: `
-          export declare function __spread(...args: any[]): any[];
+          export declare function __spread(...args: any[][]): any[];
+        `
+            },
+          ]);
+      const reflectionHost = new TsLibAwareReflectionHost(checker);
+      const evaluator = new PartialEvaluator(reflectionHost, checker);
+      const value = evaluator.evaluate(expression);
+      expect(value).toEqual([1, 2, 3]);
+    });
+
+    it('should evaluate TypeScript __spreadArrays helper', () => {
+      const {checker, expression} = makeExpression(
+          `
+        import * as tslib from 'tslib';
+        const a = [1];
+        const b = [2, 3];
+      `,
+          'tslib.__spreadArrays(a, b)', [
+            {
+              name: _('/node_modules/tslib/index.d.ts'),
+              contents: `
+          export declare function __spreadArrays(...args: any[][]): any[];
         `
             },
           ]);
@@ -612,10 +633,13 @@ runInEachFileSystem(() => {
   function getTsHelperFn(node: ts.FunctionDeclaration): TsHelperFn|null {
     const name = node.name !== undefined && ts.isIdentifier(node.name) && node.name.text;
 
-    if (name === '__spread') {
-      return TsHelperFn.Spread;
-    } else {
-      return null;
+    switch (name) {
+      case '__spread':
+        return TsHelperFn.Spread;
+      case '__spreadArrays':
+        return TsHelperFn.SpreadArrays;
+      default:
+        return null;
     }
   }
 });

packages/compiler-cli/src/ngtsc/reflection/src/host.ts

@@ -336,6 +336,10 @@ export enum TsHelperFn {
    * Indicates the `__spread` function.
    */
   Spread,
+  /**
+   * Indicates the `__spreadArrays` function.
+   */
+  SpreadArrays,
 }
 
 /**