Context
Follow-up from spanvalue v0.5.0 adoption (#38) and CSV RowIterator refactor (#39). Items here change observable output or defaults; ship behind explicit flags or a documented major bump, not as drive-by behavior changes.
Related upstream: spanvalue v0.5.0 (Simple NUMERIC wire-as-is, writer constructor errors).
Scope (one or more PRs)
1. Optional CSV formatter preset (flag required before any default flip)
Today --format=experimental_csv uses spanvalue SimpleFormatConfig via NewCSVWriter (wire-faithful scalars; NUMERIC as returned on the wire).
Proposed: add something like --csv-format=simple|spanner-cli mapping to:
spanvalue.SimpleFormatConfig() (current default)spanvalue.SpannerCLICompatibleFormatConfig() (CLI-like NUMERIC trim, STRUCT/bracket rules, etc.)
Breaking only if we later change the default from simple to spanner-cli without a major version bump. Implement the flag first; document default stability.
2. Default / major-version policy
- Document that
experimental_csv output may change when spanvalue minor versions bump; golden tests in testdata/experimental_csv/ are the contract.
- If we ever align CSV defaults with spanner-cli, treat it as a breaking release note item.
3. jq / yaml output (larger, optional split)
json/yaml paths use jqresult + protojson, not spanvalue formatters. Adopting spanvalue JSONFormatConfig / LiteralFormatConfig for cell rendering would change scalar and STRUCT appearance vs today and is a separate breaking track—only pursue with an explicit format version or new --format choice.
Out of scope for this issue
- Non-breaking additions (stats side channel, headerless CSV, new formats) → see the companion issue below.
WriteRowIterator migration → #39.
Acceptance
Context
Follow-up from spanvalue v0.5.0 adoption (#38) and CSV RowIterator refactor (#39). Items here change observable output or defaults; ship behind explicit flags or a documented major bump, not as drive-by behavior changes.
Related upstream: spanvalue v0.5.0 (Simple NUMERIC wire-as-is, writer constructor errors).
Scope (one or more PRs)
1. Optional CSV formatter preset (flag required before any default flip)
Today
--format=experimental_csvuses spanvalueSimpleFormatConfigviaNewCSVWriter(wire-faithful scalars; NUMERIC as returned on the wire).Proposed: add something like
--csv-format=simple|spanner-climapping to:spanvalue.SimpleFormatConfig()(current default)spanvalue.SpannerCLICompatibleFormatConfig()(CLI-like NUMERIC trim, STRUCT/bracket rules, etc.)Breaking only if we later change the default from
simpletospanner-cliwithout a major version bump. Implement the flag first; document default stability.2. Default / major-version policy
experimental_csvoutput may change when spanvalue minor versions bump; golden tests intestdata/experimental_csv/are the contract.3. jq / yaml output (larger, optional split)
json/yaml paths use
jqresult+protojson, not spanvalue formatters. Adopting spanvalueJSONFormatConfig/LiteralFormatConfigfor cell rendering would change scalar and STRUCT appearance vs today and is a separate breaking track—only pursue with an explicit format version or new--formatchoice.Out of scope for this issue
WriteRowIteratormigration → #39.Acceptance
spanner-cli.