fix(ivy): ngcc - recognize suffixed tslib helpers (#31614)

An identifier may become repeated when bundling multiple source files
into a single bundle, so bundlers have a strategy of suffixing non-unique
identifiers with a suffix like $2. Since ngcc operates on such bundles,
it needs to process potentially suffixed identifiers in their canonical
form without the suffix. The "ngx-pagination" package was previously not
compiled fully, as most decorators were not recognized.

This commit ensures that identifiers are first canonicalized by removing
the suffix, such that they are properly recognized and processed by ngcc.

Fixes #31540

PR Close #31614

packages/compiler-cli/ngcc/src/host/esm2015_host.ts

@@ -12,7 +12,7 @@ import {AbsoluteFsPath} from '../../../src/ngtsc/file_system';
 import {ClassDeclaration, ClassMember, ClassMemberKind, ClassSymbol, CtorParameter, Declaration, Decorator, TypeScriptReflectionHost, isDecoratorIdentifier, reflectObjectLiteral} from '../../../src/ngtsc/reflection';
 import {Logger} from '../logging/logger';
 import {BundleProgram} from '../packages/bundle_program';
-import {findAll, getNameText, hasNameIdentifier, isDefined} from '../utils';
+import {findAll, getNameText, hasNameIdentifier, isDefined, stripDollarSuffix} from '../utils';
 
 import {ModuleWithProvidersFunction, NgccReflectionHost, PRE_R3_MARKER, SwitchableVariableDeclaration, isSwitchableVariableDeclaration} from './ngcc_host';
 
@@ -889,14 +889,8 @@ export class Esm2015ReflectionHost extends TypeScriptReflectionHost implements N
     }
     const call = expression;
 
-    const helperCallFn =
-        ts.isPropertyAccessExpression(call.expression) ? call.expression.name : call.expression;
-    if (!ts.isIdentifier(helperCallFn)) {
-      return null;
-    }
-
-    const name = helperCallFn.text;
-    if (name === '__metadata') {
+    const helperName = getCalleeName(call);
+    if (helperName === '__metadata') {
       // This is a `tslib.__metadata` call, reflect to arguments into a `ParameterTypes` object
       // if the metadata key is "design:paramtypes".
       const key = call.arguments[0];
@@ -915,7 +909,7 @@ export class Esm2015ReflectionHost extends TypeScriptReflectionHost implements N
       };
     }
 
-    if (name === '__param') {
+    if (helperName === '__param') {
       // This is a `tslib.__param` call that is reflected into a `ParameterDecorators` object.
       const indexArg = call.arguments[0];
       const index = indexArg && ts.isNumericLiteral(indexArg) ? parseInt(indexArg.text, 10) : NaN;
@@ -1613,10 +1607,10 @@ export function getPropertyValueFromSymbol(propSymbol: ts.Symbol): ts.Expression
  */
 function getCalleeName(call: ts.CallExpression): string|null {
   if (ts.isIdentifier(call.expression)) {
-    return call.expression.text;
+    return stripDollarSuffix(call.expression.text);
   }
   if (ts.isPropertyAccessExpression(call.expression)) {
-    return call.expression.name.text;
+    return stripDollarSuffix(call.expression.name.text);
   }
   return null;
 }

packages/compiler-cli/ngcc/src/host/esm5_host.ts

@@ -10,7 +10,7 @@ import * as ts from 'typescript';
 
 import {ClassDeclaration, ClassMember, ClassMemberKind, ClassSymbol, CtorParameter, Declaration, Decorator, FunctionDefinition, Parameter, TsHelperFn, isNamedVariableDeclaration, reflectObjectLiteral} from '../../../src/ngtsc/reflection';
 import {isFromDtsFile} from '../../../src/ngtsc/util/src/typescript';
-import {getNameText, hasNameIdentifier} from '../utils';
+import {getNameText, hasNameIdentifier, stripDollarSuffix} from '../utils';
 
 import {Esm2015ReflectionHost, ParamInfo, getPropertyValueFromSymbol, isAssignmentStatement} from './esm2015_host';
 
@@ -659,7 +659,9 @@ function reflectArrayElement(element: ts.Expression) {
  * helper.
  */
 function getTsHelperFn(node: ts.NamedDeclaration): TsHelperFn|null {
-  const name = node.name !== undefined && ts.isIdentifier(node.name) && node.name.text;
+  const name = node.name !== undefined && ts.isIdentifier(node.name) ?
+      stripDollarSuffix(node.name.text) :
+      null;
 
   if (name === '__spread') {
     return TsHelperFn.Spread;

packages/compiler-cli/ngcc/src/utils.ts

@@ -82,3 +82,14 @@ export function resolveFileWithPostfixes(
   }
   return null;
 }
+
+/**
+ * An identifier may become repeated when bundling multiple source files into a single bundle, so
+ * bundlers have a strategy of suffixing non-unique identifiers with a suffix like $2. This function
+ * strips off such suffixes, so that ngcc deals with the canonical name of an identifier.
+ * @param value The value to strip any suffix of, if applicable.
+ * @returns The canonical representation of the value, without any suffix.
+ */
+export function stripDollarSuffix(value: string): string {
+  return value.replace(/\$\d+$/, '');
+}

packages/compiler-cli/ngcc/test/helpers/utils.ts

@@ -78,18 +78,18 @@ export function convertToDirectTsLibImport(filesystem: TestFile[]) {
   });
 }
 
-export function convertToInlineTsLib(filesystem: TestFile[]) {
+export function convertToInlineTsLib(filesystem: TestFile[], suffix: string = '') {
   return filesystem.map(file => {
     const contents = file.contents
                          .replace(`import * as tslib_1 from 'tslib';`, `
-var __decorate = null;
-var __metadata = null;
-var __read = null;
-var __values = null;
-var __param = null;
-var __extends = null;
-var __assign = null;
-`).replace(/tslib_1\./g, '');
+var __decorate${suffix} = null;
+var __metadata${suffix} = null;
+var __read${suffix} = null;
+var __values${suffix} = null;
+var __param${suffix} = null;
+var __extends${suffix} = null;
+var __assign${suffix} = null;
+`).replace(/tslib_1\.([_a-z]+)/gi, '$1' + suffix.replace('$', '$$'));
     return {...file, contents};
   });
 }

packages/compiler-cli/ngcc/test/host/esm2015_host_import_helper_spec.ts

@@ -112,15 +112,17 @@ runInEachFileSystem(() => {
 
       const DIRECT_IMPORT_FILES = convertToDirectTsLibImport(NAMESPACED_IMPORT_FILES);
       const INLINE_FILES = convertToInlineTsLib(NAMESPACED_IMPORT_FILES);
+      const INLINE_SUFFIXED_FILES = convertToInlineTsLib(NAMESPACED_IMPORT_FILES, '$2');
 
       FILES = {
         'namespaced': NAMESPACED_IMPORT_FILES,
         'direct import': DIRECT_IMPORT_FILES,
         'inline': INLINE_FILES,
+        'inline suffixed': INLINE_SUFFIXED_FILES,
       };
     });
 
-    ['namespaced', 'direct import', 'inline'].forEach(label => {
+    ['namespaced', 'direct import', 'inline', 'inline suffixed'].forEach(label => {
       describe(`[${label}]`, () => {
         beforeEach(() => {
           const fs = getFileSystem();

packages/compiler-cli/ngcc/test/host/esm5_host_import_helper_spec.ts

@@ -133,15 +133,17 @@ export { SomeDirective };
 
       const DIRECT_IMPORT_FILES = convertToDirectTsLibImport(NAMESPACED_IMPORT_FILES);
       const INLINE_FILES = convertToInlineTsLib(NAMESPACED_IMPORT_FILES);
+      const INLINE_SUFFIXED_FILES = convertToInlineTsLib(NAMESPACED_IMPORT_FILES, '$2');
 
       FILES = {
         'namespaced': NAMESPACED_IMPORT_FILES,
         'direct import': DIRECT_IMPORT_FILES,
         'inline': INLINE_FILES,
+        'inline suffixed': INLINE_SUFFIXED_FILES,
       };
     });
 
-    ['namespaced', 'direct import', 'inline'].forEach(label => {
+    ['namespaced', 'direct import', 'inline', 'inline suffixed'].forEach(label => {
       describe(`[${label}]`, () => {
         beforeEach(() => {
           const fs = getFileSystem();

packages/compiler-cli/ngcc/test/host/esm5_host_spec.ts

@@ -1669,6 +1669,30 @@ runInEachFileSystem(() => {
         expect(definition.helper).toBe(TsHelperFn.Spread);
         expect(definition.parameters.length).toEqual(0);
       });
+
+      it('should recognize TypeScript __spread helper function implementation when suffixed',
+         () => {
+           const file: TestFile = {
+             name: _('/implementation.js'),
+             contents: `
+              var __spread$2 = (this && this.__spread$2) || function () {
+                for (var ar = [], i = 0; i < arguments.length; i++) ar = ar.concat(__read(arguments[i]));
+                return ar;
+              };`,
+           };
+           loadTestFiles([file]);
+           const {program} = makeTestBundleProgram(file.name);
+           const host = new Esm5ReflectionHost(new MockLogger(), false, program.getTypeChecker());
+
+           const node =
+               getDeclaration(program, file.name, '__spread$2', ts.isVariableDeclaration) !;
+
+           const definition = host.getDefinitionOfFunction(node) !;
+           expect(definition.node).toBe(node);
+           expect(definition.body).toBeNull();
+           expect(definition.helper).toBe(TsHelperFn.Spread);
+           expect(definition.parameters.length).toEqual(0);
+         });
     });
 
     describe('getImportOfIdentifier()', () => {