Named query params with an empty array cannot be parsed

Environment details

• OS: High Sierra (10.13.6)
• Node.js version: 8.15.1
• npm version: 6.9.0
• @google-cloud/bigquery version: 2.1.0

Steps to reproduce

1. Run a query with an empty array as the value of a named query param, e.g.

const [rows] = await bq.query({
  query,
  params: {
    key: [],
  },
});

1. Query fails with This value could not be translated to a BigQuery data type.
2. Attempt to run the same query with an empty array literal in BigQuery UI or CLI and observe that the query succeeds:

...
WHERE `dataset.table`.Key IN UNNEST([])

Source of the error

I believe the error is a result of the login in https://github.com/googleapis/nodejs-bigquery/blob/ba5c82efc4c6f2aa50df2c386ab0b6894d0dd2aa/src/index.ts#L726

You can see that nodejs-bigquery is trying to determine the type of the query param from the first element. If the array is empty, value[0] is undefined, and getType_() throws an error. This issue is similar to https://github.com/googleapis/google-cloud-java/issues/2678, where they did fix it (and as they state there, it is not a limitation of the API).

EDIT: The API does seem to require specifying arrayType, e.g.

"parameterType": {
  "type": "ARRAY",
  "arrayType": {
    "type": "INT64"
  }
},

Since JavaScript (unlike Java) doesn’t store the array type info at runtime (afaik), I wonder if there’s a way to supply the type explicitly in this case. Not sure if this is more of a feature request and would you consider a PR for it.

Thanks!

[callmehiphop]

@JustinBeckwith I’m changing this to a FR but I’m going to take it on next

[meredithslota]

@callmehiphop It seems like this is fixed w/ #4271; can you or @steffnay confirm?