FallbackProvider not catch detectNetwork error

[cliff0412]

i am using the fallback-provider. however, i find it cannot handle the query requests as documented. i have 3 providers configured and quorum is set to 1. However, the query request will fail with 1 JsonRpcProvider malfunction and 2 well functioning. that is not expected!

After digging into the source code, i find the detectNetwork function is not catching the error. i have made changes to the code, and my test has been passed.

below is the new code

  async detectNetwork(): Promise<Network> {
    const networks = await Promise.all(
      this.providerConfigs.map(async (c) => {
        try {
          return c.provider.getNetwork();
        } catch (error) {
          return null;
        }
      }),
    );
    return checkNetworks(networks as Array<Network>);
  }

also in checkNetworks
i let the check continue in the for loop when null network is provided

   if (network == null) {
      continue;
    }

the way i initiated a FallbackProvider

new FallbackProvider(
      [
        {
          provider: new ethers.providers.JsonRpcProvider(url1), 
          priority: 3,
          stallTimeout: 200,
          weight: 1,
        },
        {
          provider: new ethers.providers.JsonRpcProvider(url2), 
          priority: 1,
          stallTimeout: 200,
          weight: 1,
        },
        {
          provider: new ethers.providers.JsonRpcProvider(url3), 
          priority: 2,
          stallTimeout: 200,
          weight: 1,
        },
      ],
      1,
    );