@stryker-mutator/core/src/checker/checker-retry-decorator.ts

import { Mutant } from '@stryker-mutator/api/core';
import { Logger } from '@stryker-mutator/api/logging';

import { ChildProcessCrashedError } from '../child-proxy/child-process-crashed-error.js';
import { OutOfMemoryError } from '../child-proxy/out-of-memory-error.js';
import { ResourceDecorator } from '../concurrent/index.js';

import { CheckerResource } from './checker-resource.js';

export class CheckerRetryDecorator extends ResourceDecorator<CheckerResource> implements CheckerResource {
  constructor(producer: () => CheckerResource, private readonly log: Logger) {
    super(producer);
  }

  public async check(checkerName: string, mutants: Mutant[]): ReturnType<CheckerResource['check']> {
    return this.tryAction(() => this.innerResource.check(checkerName, mutants));
  }

  public async group(checkerName: string, mutants: Mutant[]): ReturnType<CheckerResource['group']> {
    return this.tryAction(() => this.innerResource.group(checkerName, mutants));
  }

  private async tryAction<T>(act: () => Promise<T>): Promise<T> {
    try {
      return await act();
    } catch (error) {
      if (error instanceof ChildProcessCrashedError) {
        if (error instanceof OutOfMemoryError) {
          this.log.warn(`Checker process [${error.pid}] ran out of memory. Retrying in a new process.`);
        } else {
          this.log.warn(`Checker process [${error.pid}] crashed with exit code ${error.exitCode}. Retrying in a new process.`, error);
        }
        await this.recover();
        return act();
      } else {
        throw error; //oops
      }
    }
  }
}