Replaces the placeholder "trust STRICT" body of do_change_column_type
with the per-cell transformer matrix from ADR-0017. Adds:
- src/type_change.rs: CellOutcome { Clean / Lossy / Incompatible }
+ transform_cell + static_refusal covering every matrix pair
from §3 (54 unit tests).
- --force-conversion and --dont-convert flags on `change column`
(mutually exclusive at parse time per §5).
- Refined PK rule (§4.1): refused only when the column has an
inbound FK and fk_target_type would change. Outbound-FK columns
still refused outright (§4.2). PK / shortid uniqueness checked
post-transformation (§4.3).
- Bordered diagnostic tables (lossy / incompatible / collision)
via the pretty-table renderer (§7) — uses ADR-0016's primitives.
- [client-side] success note (§6) when any cell was rewritten.
- Friendly wrapper for engine-level errors under --dont-convert
so no engine vocabulary leaks (ADR-0002 user-facing posture).
ADR-0017 §3 + §7 amended in place (with user sign-off): serial->int
added explicitly to the always-clean matrix, and diagnostic rows
identify themselves by PK value(s) rather than positional indices
(SQLite returns rows unordered without ORDER BY, so positional
"row 5" is unaddressable).
Tests: 449 -> 517 (+68). Clippy clean with nursery lints.
Specifies the curated per-cell classification (clean /
lossy / incompatible) for column type changes, the static
transformer matrix (numeric chains, text↔structured types,
always-clean stringifications), and the PK / shortid /
uniqueness-bearing handling. Replaces the B2/C2
placeholder of "rely on engine STRICT and surface its
errors" with a learner-friendly model that:
* refuses incompatibles up-front,
* refuses lossy conversions by default with a re-run-with-
--force-conversion hint,
* refines the PK refusal: an inbound-FK PK is only refused
when the new type would change the FK target type
(so `serial → int` and `shortid → text` on FK-referenced
PKs are allowed; `int → text` etc. still refuse),
* adds a post-transformation uniqueness check for PK and
shortid columns,
* uses the pretty-table renderer (ADR-0016) for all
diagnostic row lists,
* emits a `[client-side] …` note in the success summary
whenever the transformer rewrote any cell.
`--force-conversion` accepts loss; `--dont-convert` skips
the client-side layer entirely; mutually exclusive.
Forward-look: a future iteration may add resolution flags
(`--default 0`, `--on-incompatible '<value>'`).
Also amends ADR-0002 with a new "User-facing posture"
section cementing that the database engine choice is an
implementation detail and is never named in user-visible
strings. Adds a corresponding bullet to CLAUDE.md's
working-style rules so every session picks it up.
Implementation lands as a follow-up.
claude@clouddev1