visitDependency() — react Function Reference

Source Code

compiler/packages/babel-plugin-react-compiler/src/HIR/PropagateScopeDependenciesHIR.ts lines 558–610

  visitDependency(maybeDependency: ReactiveScopeDependency): void {
    /*
     * Any value used after its originally defining scope has concluded must be added as an
     * output of its defining scope. Regardless of whether its a const or not,
     * some later code needs access to the value. If the current
     * scope we are visiting is the same scope where the value originates, it can't be a dependency
     * on itself.
     */

    /*
     * if originalDeclaration is undefined here, then this is not a local var
     * (all decls e.g. `let x;` should be initialized in BuildHIR)
     */
    const originalDeclaration = this.#declarations.get(
      maybeDependency.identifier.declarationId,
    );
    if (
      originalDeclaration !== undefined &&
      originalDeclaration.scope.value !== null
    ) {
      originalDeclaration.scope.each(scope => {
        if (
          !this.#isScopeActive(scope) &&
          !Iterable_some(
            scope.declarations.values(),
            decl =>
              decl.identifier.declarationId ===
              maybeDependency.identifier.declarationId,
          )
        ) {
          scope.declarations.set(maybeDependency.identifier.id, {
            identifier: maybeDependency.identifier,
            scope: originalDeclaration.scope.value!,
          });
        }
      });
    }

    // ref.current access is not a valid dep
    if (
      isUseRefType(maybeDependency.identifier) &&
      maybeDependency.path.at(0)?.property === 'current'
    ) {
      maybeDependency = {
        identifier: maybeDependency.identifier,
        reactive: maybeDependency.reactive,
        path: [],
      };
    }
    if (this.#checkValidDependency(maybeDependency)) {
      this.#dependencies.value!.push(maybeDependency);
    }
  }