getBreakTarget() — react Function Reference

Source Code

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/BuildReactiveFunction.ts lines 1384–1421

  getBreakTarget(block: BlockId): {
    block: BlockId;
    type: ReactiveTerminalTargetKind;
  } {
    let hasPrecedingLoop = false;
    for (let i = this.#controlFlowStack.length - 1; i >= 0; i--) {
      const target = this.#controlFlowStack[i]!;
      if (target.block === block) {
        let type: ReactiveTerminalTargetKind;
        if (target.type === 'loop') {
          /*
           * breaking out of a loop requires an explicit break,
           * but only requires a label if breaking past the innermost loop.
           */
          type = hasPrecedingLoop ? 'labeled' : 'unlabeled';
        } else if (i === this.#controlFlowStack.length - 1) {
          /*
           * breaking to the last break point, which is where control will transfer
           * implicitly
           */
          type = 'implicit';
        } else {
          // breaking somewhere else requires an explicit break
          type = 'labeled';
        }
        return {
          block: target.block,
          type,
        };
      }
      hasPrecedingLoop ||= target.type === 'loop';
    }

    CompilerError.invariant(false, {
      reason: 'Expected a break target',
      loc: GeneratedSource,
    });
  }