Trying to make postgres interpolate table name and columns with COPY

test_import.mjs

import postgres from 'postgres'
import { pipeline } from 'node:stream/promises'
import { Readable } from 'node:stream'

// Enter your local values
const connectUrl = 'postgres://user:password@host/db'

const sql = await postgres(connectUrl, { debug: true })

async function importData (tableName, data) {
  await sql`DROP TABLE IF EXISTS ${sql(tableName)}`
  await sql`CREATE TABLE ${sql(tableName)} (
      name varchar(32),
      age int
    )`

  // Translate data to tab-separated, newline terminated values
  const tsv = data.map(rec => [...Object.values(rec)].join('\t') + '\n')
  // console.log('tsv:', tsv)
  const readStream = Readable.from(tsv)
  const cols = Object.keys(data[0])
  // console.log('cols:', cols)

  // This is what I *want* to do
  const query = sql`COPY ${sql(tableName)} (${sql(cols)}) FROM STDIN`
  // --> Error: Could not infer helper mode

  // Try interpolating columns but not table name
  // with parens around columns
  // const query = sql`COPY test_table ( ${sql(cols)} ) FROM STDIN`
  // --> Error: Could not infer helper mode

  // Try without parens
  // const query = sql`COPY test_table ${sql(cols)} FROM STDIN`
  // --> Error: Could not infer helper mode

  // Try interpolating tablename but not columns
  // const query = sql`COPY ${sql(tableName)} ( name, age ) FROM STDIN`
  // --> PostgresError: syntax error at end of input

  // Only works without any interpolation
  // const query = sql`COPY test_table ( name, age ) FROM STDIN`

  // console.log('query:', query)
  const writeStream = await query.writable()
  await pipeline(readStream, writeStream)
}

const testTable = 'test_table'
const testData = [
  {
    name: 'Murray',
    age: 68
  },
  {
    name: 'Walter',
    age: 80
  }
]
try {
  await importData(testTable, testData)
  const contents = await sql`SELECT * from ${sql(testTable)}`
  console.log(contents)
} catch (err) {
  console.error('testImport:', err)
}
await sql.end()