Speech API speechContexts not recognising arrays

[CharlotteGore]

Despite passing an array to speechContext.phrases, I am getting the following error:

ERROR: TypeError: .google.cloud.speech.v1.RecognitionConfig.speechContexts: array expected
    at Type.RecognitionConfig$fromObject [as fromObject] (eval at Codegen (/redacted/node_modules/@protobufjs/codegen/index.js:50:33), <anonymous>:55:9)
    at Type.fromObject (/redacted/node_modules/protobufjs/src/type.js:538:25)
    at Type.LongRunningRecognizeRequest$fromObject [as fromObject] (eval at Codegen (/redacted/node_modules/@protobufjs/codegen/index.js:50:33), <anonymous>:10:21)
    at Type.fromObject (/redacted/node_modules/protobufjs/src/type.js:538:25)
    at serialize (/redacted/node_modules/grpc/src/protobuf_js_6_common.js:70:23)
    at ServiceClient.Client.makeUnaryRequest (/redacted/node_modules/grpc/src/client.js:544:17)
    at apply (/redacted/node_modules/lodash/lodash.js:499:17)
    at ServiceClient.wrapper (/redacted/node_modules/lodash/lodash.js:5356:16)
    at /redacted/node_modules/@google-cloud/speech/src/v1/speech_client.js:175:39
    at timeoutFunc (/redacted/node_modules/google-gax/lib/api_callable.js:171:12)

Environment details

• OS: OSX v10.11.6
• Node.js version: v8.11.1
• npm version: 5.6.0
• google-cloud-node version: 196.0.0

Steps to reproduce

Code is here, it's mostly copied straight from the documentation. I have other code generating the real array but I tested it with the simplest possible array for testing and still getting the same result.

const config = {
  enableWordTimeOffsets: true,
  encoding: 'FLAC',
  sampleRateHertz: '16000',
  languageCode: 'en-GB',
  speechContexts: {
    phrases: ['dog', 'cat']
  }
};

const audio = {
  uri: 'gs://bucket/audio.flac'
};

const request = {
  config,
  audio,
};

client
  .longRunningRecognize(request)
  .then(data => {
    const operation = data[0];
    // Get a Promise representation of the final result of the job
    return operation.promise();
  })
  .then(data => {
    const response = data[0];
    console.log(`${JSON.stringify(response, null, 2)}`);
  })
  .catch(err => {
    console.error('ERROR:', err);
  });

[stephenplusplus]

This issue was moved to googleapis/nodejs-speech#56.