ToolUp.DataSources.Common 0.22.0

ToolUp.DataSources.Common

The vendor-free support layer shared by the ToolUp.DataSources.* IDataSource companions. BCL only — no cloud SDK, no database driver (GP 1). A consumer never references this package directly; it arrives transitively with whichever connector they compose.

Six connectors needed the same five things, and duplicating them six times would have meant six places for the CSV escaping or the credential-fallback order to drift:

Why one CSV format for the whole family

IDataSource.Query returns opaque bytes and the ingestor stores them through IDataObjectStore without looking inside, so the format is the connector's to choose. Choosing the same one everywhere means a module that reads one warehouse's output reads all of them.

CSV specifically: ToolUp.Tabular already reads it, and Athena stages result sets to S3 as CSV natively — so for at least one connector the wire format is a re-emission rather than a translation. Types are recovered from GetSchema, not from the payload.

Two details that are load-bearing rather than incidental:

• Values render invariant-culture. A connector running on a comma-decimal host would otherwise corrupt every number in the payload, silently and unrecoverably. DateTime renders ISO-8601 round-trip ("O"), byte[] base64, bool as true/false, NULL and DBNull as the empty field.
• No BOM. A UTF-8 BOM appears as a stray character in the first header cell for every naive downstream parser.

Why identifiers are validated rather than parameterised

SqlIdentifier exists because the eight backends across this family do not share one parameter marker — @p, :p, {p:String}, ? — and a connector whose safety depended on getting four markers right in eighteen places is a connector waiting to be wrong.

Catalogue queries therefore interpolate schema and table names, and every interpolated identifier is first validated against ^[A-Za-z_][A-Za-z0-9_$]{0,127}$ and refused as SchemaMismatch if it does not match. Quoted identifiers containing spaces, dots or Unicode are refused rather than escaped — deliberately narrower than what any backend permits. quoteLiteral doubles single quotes on top, as a second and independent line of defence.

Testing

Everything here is a total function or an in-process async, so all of it is covered by the always-on arm of src/ToolUp.DataSources.Tests — no credential, no server, no network.