COPY...FROM stream doesn't work with interpolated values

[partap]

I'm trying to import values using COPY FROM piped from a readable stream, but the sql helper only gives me errors.

The example from the docs works as written:

const userStream = Readable.from([
  'Murray\t68\n',
  'Walter\t80\n'
])
const query = await sql`copy test_table ( name, age ) from stdin`.writable()
await pipeline(userStream, query);

But, if I want to interpolate the table and/or column names, it doesn't work:

const tableName = 'test_table'
const cols = [ 'name', 'age' ]

// Interpolate both table name and columns
const query = await sql`copy ${sql(tableName)} (${sql(cols)}) from stdin`.writable()
// --> Error: Could not infer helper mode

// Only interpolate columns
const query = await sql`copy test_table (${sql(cols)}) from stdin`.writable()
// --> Error: Could not infer helper mode

// Only interpolate table name
const query = await sql`copy ${sql(tableName)} (name, age) from stdin`.writable()
// --> PostgresError: syntax error at end of input

There's a full (non) working example here: https://gist.github.com/partap/fefc18a0d294dae033c893f2d2828187

[porsager]

Nice finds. Finally had a little time to fix that.