TypeError when inserting an object with null prototype

[jfhr]

Environment details

• OS: MacOS 13.2.1
• Node.js version: v18.10
• npm version: 8.19.2
• @google-cloud/bigquery version: 6.1.0

Steps to reproduce

1. Create an object with Object.create(null)
2. Give the object any properties with BigQuery-compatible names and values
3. Create a stream with new BigQuery().dataset('...').table('...').createInsertStream()
4. Write the object to the stream

This causes a TypeError: Cannot read properties of undefined (reading 'name')

This is cause by line 573 in table.ts, which reads:

    const constructorName = value.constructor.name;

For an object created with Object.create(null), constructor is undefined so this causes an error.

Suggestion: Change this line to:

    const constructorName = value.constructor?.name;

This should allow it to handle null constructor objects without changing anything for other types.