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Title: fix(ngcc): libraries using spread in object literals cannot be processed by devversion · Pull Request #34661 · angular/angular · GitHub

Open Graph Title: fix(ngcc): libraries using spread in object literals cannot be processed by devversion · Pull Request #34661 · angular/angular

X Title: fix(ngcc): libraries using spread in object literals cannot be processed by devversion · Pull Request #34661 · angular/angular

Description: Consider a library that uses a shared constant for host bindings. e.g. export const BASE_BINDINGS= { '[class.mat-themed]': '_isThemed', } ---- @Directive({ host: {...BASE_BINDINGS, '(click)': '...'} }) export class Dir1 {} @Directive({ host: {...BASE_BINDINGS, '(click)': '...'} }) export class Dir2 {} Previously when these components were shipped as part of the library to NPM, consumers were able to consume Dir1 and Dir2. No errors showed up. Now with Ivy, when ngcc tries to process the library, an error will be thrown. The error is stating that the host bindings should be an object (which they obviously are). This happens because TypeScript transforms the object spread to individual Object.assign calls (for compatibility). The partial evaluator used by the @Directive annotation handler is unable to process this expression because there is no integrated support for Object.assign. In View Engine, this was not a problem because the metadata.json files from the library were used to compute the host bindings. To fix this, we add support for Object.assign. Unfortunately there is no safe and easy way to detect if a property access resolves to the assign method of the global Object variable. To ensure that the partial evaluator can resolve both the "lhs" and "rhs" of the property access, we add the needed Object.assign types to the ngcc program. Fixes #34659

Open Graph Description: Consider a library that uses a shared constant for host bindings. e.g. export const BASE_BINDINGS= { '[class.mat-themed]': '_isThemed', } ---- @Directive({ host: {...BASE_BIND...

X Description: Consider a library that uses a shared constant for host bindings. e.g. export const BASE_BINDINGS= { '[class.mat-themed]': '_isThemed', } ---- @Directive({ hos...

Opengraph URL: https://github.com/angular/angular/pull/34661

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