Files
rdbms-playground/docs/requirements.md
T
claude@clouddev1 305e5083d5 INSERT/UPDATE/DELETE + value model + auto-show, with polish
DSL data operations (ADR-0014):
- insert into T [(cols)] values (vals); short form
  insert into T (vals) omits values keyword for friendlier
  syntax.
- update T set ... where col=val | --all-rows; delete from T
  where col=val | --all-rows; show data T.
- Value AST (Number/Text/Bool/Null) with per-column-type
  validation in the executor: int/real/decimal/bool/date/
  datetime/shortid each accept a documented literal shape
  and produce friendly format errors naming the column.
- INSERT short form fills non-auto-generated columns in
  schema order; auto-fills serial via SQLite and shortid
  via the new generator (T2).
- `add column [to table] T: c (type)` -- `to table` now
  optional.

Database:
- insert/update/delete via prepared statements with bound
  rusqlite::types::Value parameters.
- InsertResult/UpdateResult/DeleteResult: writes return
  rows_affected plus the affected row(s) only (not the whole
  table), so users see exactly what changed.
- INSERT shows the just-inserted row via last_insert_rowid.
- UPDATE captures matching rowids up-front and fetches them
  post-update -- works even if the UPDATE changed the WHERE
  column.
- DELETE reports per-relationship cascade effects by row-
  count diffing inbound child tables; UPDATE-side cascades
  are not yet detected (would need value diffing).
- query_data formats cells (booleans true/false, NULLs as
  None).

FK error enrichment:
- Now lists both outbound (INSERT/UPDATE relevance) and
  inbound (DELETE/UPDATE on parent relevance) FKs from the
  metadata, so RESTRICT errors point at the children
  blocking the delete.
- RelationshipSelector has a proper Display impl -- "no
  such relationship" reads cleanly.

Relationship display:
- target_table for AddRelationship/DropRelationship now
  returns the parent (1-side); structure rendering after
  add/drop shows that side's "Referenced by:" entry,
  matching the `from <Parent>` direction of the command.
- [ok] summary uses display_subject so relationship
  commands show both endpoints (`from P.col to C.col`)
  rather than a single misleading table name.
- Auto-name format `<Parent>_<pcol>_to_<Child>_<ccol>`
  (matches the from..to direction).

Output rendering and scrolling:
- Wrap-aware scroll: renderer reports both visible-row
  count and total wrapped-row count to App; scroll math
  caps against actual displayable rows. Long lines wrap;
  the bottom line is always reachable; PageUp/PageDown work
  correctly even after paging past the buffer top.
- Multi-line messages (FK error enrichment, cascade summary)
  split into single-line OutputLines at creation time so
  wrap/scroll math agree.

Runtime / events:
- New AppEvent variants for Insert/Update/Delete success
  carrying typed result structs; DslDataSucceeded reserved
  for show-data queries.

Docs:
- ADR-0014 covers data-op grammar, value model, --all-rows
  safety, auto-show.
- requirements.md: C5 done, T2 done, V2 partial (basic data
  view), V5 partial (show data added). New entries: C5a
  complex WHERE expressions; H1 progress note for FK
  enrichment; H1a (strong syntax-help in parse errors).

Tests: 200 passing (183 lib + 17 integration), 0 skipped.
Includes parser, type-validation, DB write/read, FK-failure
enrichment, cascade-delete propagation, focused-auto-show
behaviour, scroll-cap invariants. Clippy clean with nursery
enabled.
2026-05-07 16:33:25 +00:00

428 lines
19 KiB
Markdown
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# RDBMS Playground — Requirements (Phase 1)
This document is the **consolidated Phase 1 requirements
checklist** for RDBMS Playground. It captures everything the
project has committed to so far, derived from the design
conversation and the ADRs in `docs/adr/`.
**Purpose.** Phase 5 verification at every milestone measures
delivered work against this checklist. An item not on this list
was not promised; an item silently dropped without confirmation
is a process failure.
**Scope.** The list is intentionally coarse — each item is a
unit of "satisfied / not satisfied" judgement. When an item is
taken up for implementation, it is decomposed further in a
backlog (initially in this repo, later in GitHub issues once the
repo is pushed).
## Status legend
- `[ ]` — open, not yet implemented
- `[x]` — satisfied (implemented + tested)
- `[~]` — deferred, awaiting an ADR or further design before any
implementation
- `[-]` — explicitly out of scope (rationale at the bottom)
## Test baseline
No test suite exists yet — the repo currently contains only
docs. The baseline is therefore "0 passing, 0 failing, 0
skipped." Subsequent phases establish the suite and measure
against it.
---
## Distribution and install
- [ ] **D1** Cross-platform binaries: Linux, macOS, Windows on
x86_64 and aarch64.
- [ ] **D2** Single static binary, no runtime dependencies.
- [ ] **D3** Released via prebuilt binaries plus Homebrew, Scoop,
`winget`, and `cargo binstall`.
## TUI shell
- [ ] **S1** Three-region layout: items list (left), output
panel (right), input field (bottom).
- [ ] **S2** Items list shows tables and per-table indexes;
designed to extend to additional element kinds (relations,
views, etc.) without restructuring.
*(Progress: tables are listed live from the database; indexes
pending alongside C3 index support.)*
- [ ] **S3** Output panel renders a visualization of the
currently selected item and supports multiple tabs.
- [ ] **S4** Hint area below the input field; keyboard-toggleable
for inspecting hints about the current input or last error.
- [ ] **S5** Mode label and distinct border style on the input
field communicate the current input mode at all times.
## Input field
- [ ] **I1** Multi-line entry that auto-expands; Ctrl-Enter (or
equivalent) submits, plain Enter inserts a newline.
- [ ] **I1a** In-line cursor editing in the input field: Left /
Right arrows move the cursor by character (UTF-8 boundaries
honoured), Home / End jump to the extremes, Delete removes the
character at the cursor, Backspace removes the character
before. Insertion happens at the cursor position. *(Implemented;
multi-line editing per I1 still pending.)*
- [ ] **I1b** Readline-style cursor shortcuts: Ctrl-A / Ctrl-E
as aliases for Home / End for users on keyboards without those
keys (and for ergonomics in command-driven workflows). Likely
followed by Ctrl-W (delete previous word), Ctrl-K (delete to
end), Ctrl-U (delete to start). Pending.
- [ ] **I2** Persistent navigable input history (project-scoped,
with a global rolling history also available).
*(Progress: in-memory navigable history (Up/Down arrows, draft
preservation, dedup of consecutive duplicates) is implemented;
persistence across sessions arrives with track 2's project
storage.)*
- [ ] **I3** Tab completion for app commands, DSL keywords, table
names, column names, and SQL keywords.
- [ ] **I4** Syntax highlighting for both the DSL and SQL.
- [ ] **I5** In-flight query/command cancellation (Ctrl-C in the
output area or input field).
## Input modes (per ADR-0003)
- [ ] **M1** Simple mode is the default. It accepts DSL data
commands and the canonical app-level commands; raw SQL is
rejected with a friendly hint.
- [ ] **M2** Advanced mode accepts SQL plus the canonical
app-level commands without any sigil.
- [ ] **M3** Prefixing a single line with `:` in simple mode is a
one-shot advanced escape (with the prompt label updated). The
`mode simple` / `mode advanced` command switches modes
persistently.
## App-level commands (per ADR-0003)
- [ ] **A1** All canonical app-level commands implemented and
available in both modes: `save`, `save as`, `load`, `new`,
`export`, `import`, `seed`, `replay`, `undo`, `redo`, `mode`,
`help`, `hint`, `quit`.
*(Progress: `quit`/`q` and `mode simple|advanced` implemented;
the rest land alongside the features they belong to — `save`
and friends in track 2, `seed` in the seeding iteration, etc.)*
## DSL data commands
- [ ] **C1** Table operations: create / drop / rename.
*(Progress: create + drop done; rename pending.)*
- [ ] **C2** Column operations: add / drop / rename / change
type, including the rebuild-table dance behind the scenes
where SQLite ALTER cannot do it directly.
*(Progress: add done; drop/rename/change-type pending — the
rebuild-table dance is the gating piece, B2.)*
- [ ] **C3** Schema constraints: primary key (single and
compound), foreign key with `ON DELETE` / `ON UPDATE` referential
actions, indexes, `NOT NULL`, `UNIQUE`, `CHECK`, `DEFAULT`.
*(Progress: PK including compound done at create-table time;
FK with `ON DELETE` / `ON UPDATE` actions done (ADR-0013) —
declared via `add 1:n relationship`; symmetric outbound +
inbound view in the structure renderer; type compatibility
validated at declaration via `Type::fk_target_type()`. Index,
`NOT NULL`, `UNIQUE`, `CHECK`, `DEFAULT` still pending.)*
- [~] **C3a** Modify relationship: `modify relationship <name>
[on delete <action>] [on update <action>]`. Users can achieve
the same via drop + add today; one-step modify is a small
follow-up using the existing rebuild-table machinery. ADR
pending.
- [ ] **C4** Convenience: `create m:n relationship from <T1> to
<T2>` produces an auto-named junction table the user can rename;
pulls primary keys and FK definitions automatically.
- [x] **C5** Data operations: insert / update / delete via DSL.
*(ADR-0014. INSERT short and long forms, UPDATE/DELETE with
required WHERE plus `--all-rows` opt-in, `show data <T>`,
per-column-type value-literal validation, FK enforcement
with metadata-driven error enrichment, auto-show after
writes. Bulk insert, complex WHERE expressions, and SELECT
in advanced mode are explicitly tracked separately — see
C5a below.)*
- [~] **C5a** Complex WHERE expressions (AND/OR/comparison
operators/LIKE) for UPDATE/DELETE/show-data filtering. Tracks
the natural progression from DSL into real SQL fluency that
motivates the playground; design and ADR pending.
## SQL handling
- [ ] **Q1** SQL parsed via `sqlparser-rs`; supported subset is
defined (specifics deferred to a future ADR).
*(Progress: DSL is parsed via `chumsky` (ADR-0009); SQL
handling in advanced mode is still a placeholder echo.)*
- [ ] **Q2** Non-standard syntax rejected with a clear message
pointing at the supported subset.
- [x] **Q3** User-facing simplified types map transparently to
SQLite STRICT types in generated DDL. *(All ten types implemented
and tested.)*
- [~] **Q4** Supported SQL subset specification — design and ADR
pending. Q1 cannot be marked satisfied without it.
## Database backend (per ADR-0002)
- [x] **B1** SQLite via `rusqlite`; all tables created `STRICT`;
`PRAGMA foreign_keys = ON` per connection. *(Database accessed
through a dedicated worker thread per ADR-0010.)*
- [ ] **B2** Schema evolution uses the rebuild-table technique
internally where SQLite `ALTER TABLE` cannot.
*(Progress: rebuild-table primitive landed (ADR-0013) and is
used by `add_relationship` / `drop_relationship`. Reuse for
column drops/renames/type changes pending; the primitive is
designed to support those without further architectural work.)*
- [ ] **B3** Query timeout and cancellation supported (no
cartesian-join-of-doom can hang the app).
*(Progress: the worker-thread architecture is in place; the
cancellation/timeout protocol on top of it is pending.)*
## Type system (per ADR-0005)
- [x] **T1** All ten user-facing types implemented: `text`,
`int`, `real`, `decimal`, `bool`, `date`, `datetime`, `blob`,
`serial`, `shortid`. *(Mapping to SQLite STRICT covered by
ADR-0005; FK target type rule by ADR-0011.)*
- [x] **T2** `shortid` generation: base58, 1012 characters,
omits ambiguous characters; generated client-side at insert.
*(Implemented per ADR-0014; auto-fills omitted shortid
columns and validates user-supplied values against the same
alphabet and length range.)*
- [ ] **T3** Compound primary keys handled end-to-end (DSL,
storage, display, FK reference).
*(Progress: DSL grammar (`with pk a:int,b:int`), storage, and
table-info description are all present; the FK iteration
references single-column PKs only — compound-key FK references
remain pending.)*
## Visualizations
- [ ] **V1** Single-element views render in the output pane: a
selected table as its structure (columns, types, keys,
constraints); a selected relationship as two tables joined by
a line.
*(Progress: a basic structure view (column rows with SQLite
type names) is rendered after each successful DDL; pretty
rendering, selection nav, and relationship line-art pending —
see V4 for the broader direction.)*
- [ ] **V2** SQL query results render as a dynamic table view in
the output pane, with multiple result tabs supported.
*(Progress: a basic aligned-column data view is rendered for
`show data` and after every write (ADR-0014). Pretty
box-drawing tables with truncation/scroll handling, plus
multi-tab support, remain in V4 territory.)*
- [~] **V3** Full ER-diagram export (whole-database graph, viewed
outside the TUI) — low priority; design and ADR pending.
- [~] **V4** Output panel as a *scrollable per-session log* with
inline rich rendering. Direction agreed in conversation: the
output area is a chronological journal of operations and
selections (e.g. a "selected table X" entry with the rendered
structure underneath); structure renderings choose between a
compact ASCII-table form and a vertical line-per-column form
based on dimensions; the log is exportable to Markdown so
learners can keep a record of their session. Design and ADR
pending before any implementation.
*(Partial: PageUp / PageDown scrolling of the existing line
buffer is in, with new output snapping the view to the most
recent. The full V4 scope — smart structure rendering, log
styling, Markdown export, scroll indicator — remains pending.)*
- [ ] **V5** `show <kind> [<name>]` family of commands for
redisplaying schema info on demand. *(Progress: `show table
<name>` and `show data <Table>` implemented;
`show tables`, `show relationships`, etc. pending.)*
## Project lifecycle (per ADR-0004)
- [ ] **P1** An auto-named temporary project is created on
startup unless a project is specified, and stored in a
platform-standard path
(e.g. `~/.rdbms-playground/projects/temp-<name>`).
- [ ] **P2** `save` elevates a temp project to a named project at
a chosen location.
- [ ] **P3** Project is always saved as changes occur — there is
no manual dirty state.
- [ ] **P4** `load` opens a picker listing temp projects with
timestamps, with the option to browse to an arbitrary location.
- [ ] **P5** `playground.db` is a derived artifact: rebuilt
silently when missing, rebuilt with confirmation and a change
summary when present (per ADR-0004).
## Project file format (per ADR-0004)
- [ ] **F1** `project.yaml` with `version` field carries schema,
relationships, and project metadata; `data/<table>.csv` carries
table data (UTF-8, header row, RFC 4180).
- [ ] **F2** A `.gitignore` template (excluding `playground.db`)
is created in each new project.
- [ ] **F3** Project file format includes a registered-migrator
mechanism so older `version` values load cleanly as the format
evolves. (Exercised once `version` increments past 1; the
mechanism itself is built in v1.)
## Undo and replay (per ADR-0006)
- [ ] **U1** Auto-snapshot before destructive operations into a
ring buffer (initial size N=10, tunable).
- [ ] **U2** `undo` restores the most recent snapshot; `redo`
re-applies; both prompt for confirmation showing the snapshot
timestamp and a summary of the changes that will be discarded.
- [ ] **U3** `history.log` records every successfully executed
command in append-only form.
- [ ] **U4** `replay` runs commands from a `history.log` or
`.commands` file.
## Sharing and export (per ADR-0007)
- [ ] **E1** `export` produces a zip excluding `playground.db`;
default filename `YYYYMMDD-<projectname>-export-NN.zip` with a
non-clobbering two-digit sequence.
- [ ] **E2** User documentation includes sharing recipes for
git, email, and direct file transfer.
## Sample data / seeding
- [ ] **SD1** `seed <table> [count]` generates plausible fake
data; junction tables are seeded with valid foreign-key
references drawn from existing parent rows.
- [~] **SD2** Detailed seeding rules (per-type generators,
locale, determinism, override hooks) — design and ADR pending.
## Query analysis
- [ ] **QA1** `EXPLAIN QUERY PLAN` is run on demand for queries;
output is rendered as an annotated tree highlighting full
scans, index use, and join order.
- [~] **QA2** Plan rendering specifics (tree layout, annotation
taxonomy, colour scheme) — design and ADR pending.
## Hints, help, errors
- [ ] **H1** Friendly error-rewriting layer translates SQLite
error messages into learner-friendly equivalents.
*(Progress: foreign-key constraint failures are enriched
with both inbound and outbound relationship listings (so
RESTRICT errors point at the children that still reference
this table); full SQL → English translation pending.)*
- [ ] **H1a** Strong syntax-help in parse errors. When the user
types something near-correct (e.g. `insert into T ('Oli')` —
forgotten `values`; or `update T set x=1` — missing WHERE),
the error should *name the missing keyword or clause* rather
than just point at the unexpected character. This is a
separate effort from H1 (which targets database errors); it
targets parser errors. Pending — multiple targeted fixes
shipping piecemeal so far (e.g. `values` becoming optional in
INSERT removes one such case).
- [ ] **H2** `hint` provides contextual help for the current
input or the most recent error.
- [ ] **H3** `help` provides general reference and per-command
help.
## CLI
- [ ] **L1** Load a project via a positional CLI argument.
- [~] **L2** Submit a command alongside project load — deferred,
not v1.
## Tutorials and lessons
- [~] **TU1** Tutorial / lesson system — design and ADR pending
before any implementation. Out of v1 unless an ADR is written.
## Testing (per ADR-0008)
- [ ] **TT1** Tier 1: `cargo test` + `proptest` covering
pure-logic modules (parser, dispatcher, type mapping, project
I/O, snapshot ring buffer, replay log).
- [ ] **TT2** Tier 2: Ratatui `TestBackend` + `insta` snapshots
for representative views.
- [ ] **TT3** Tier 3: synthetic event-loop integration tests
covering the user-facing flows in this checklist.
- [ ] **TT4** Tier 4: PTY-based end-to-end for the four critical
flows named in ADR-0008 (cold launch → DDL → quit; save →
reopen; export → import → rebuild; undo after DROP).
- [ ] **TT5** CI runs all tiers on Linux, macOS, and Windows on
stable Rust.
## Cross-cutting
- [ ] **X1** Comprehensive logging via the project's logging
infrastructure per `CLAUDE.md` (decision points, parameter
values, fallback paths).
- [~] **X2** Language: English-only for v1; multi-language is an
open question to revisit later.
- [~] **X3** Accessibility: TUI screen-reader support is
best-effort and not a v1 commitment; revisit if user need
emerges.
---
## Non-functional requirements
NFRs are quality bars rather than discrete features. Where a
target is measurable, it is stated numerically; where it is
necessarily qualitative, the criterion is named and the bar is
"reviewer judgement against the criterion."
- [ ] **NFR-1 Performance — startup.** Cold launch to first
rendered frame under 500ms on commodity hardware (developer
laptop, mid-range desktop). Measured in CI on the Linux runner
as a regression gate.
- [ ] **NFR-2 Performance — input latency.** Keystroke-to-render
latency under 16ms during normal editing; long-running queries
must execute off the UI thread so the interface remains
responsive (typing, scrolling, mode switching) while a query is
running.
- [ ] **NFR-3 Performance — resource footprint.** Idle memory
under 50MB on the smallest target platform; no busy-loops; CPU
near zero when waiting for input.
- [ ] **NFR-4 Visual quality — distinctive design.** Colour
palette and typography are deliberate and consistent across
views; layout uses Unicode box-drawing and symbols where they
add clarity; rendering avoids the generic flat-default look
that ships with most TUI frameworks. Criterion: a reviewer can
identify the app from a screenshot of any view.
- [ ] **NFR-5 Visual quality — colour use.** Colour conveys
information rather than decoration: mode indication, query
result types (numeric vs text vs null), error severity,
syntax highlighting categories. Foreground/background
combinations meet WCAG-AA contrast (4.5:1 for normal text)
even though we have not committed to broader accessibility.
- [ ] **NFR-6 Cross-platform parity.** Behaviour and visual
quality are equivalent across Linux, macOS, and Windows on
crossterm-supported terminals. Platform-specific divergence
(e.g. font fallbacks) is documented, not silently tolerated.
- [ ] **NFR-7 Light and dark background support.** The colour
scheme remains legible and visually coherent on both light and
dark terminal backgrounds. The mechanism (auto-detect via
terminal query, explicit user setting, or both) is an
implementation choice, but the outcome is non-negotiable: no
dark-on-dark or light-on-light readability failures on either
background.
---
## Explicitly out of scope
- [-] **N1** Hosted publishing platform — per ADR-0007. Sharing
is local-artifact based.
- [-] **N2** Real UUID column type — per ADR-0005. The `shortid`
type covers the pedagogical need at TUI-friendly width.
- [-] **N3** Cross-emulator visual regression coverage — per
ADR-0008. Crossterm abstracts terminals adequately; we revisit
only if a real regression surfaces.
---
## Maintenance
This document is updated whenever:
- A new requirement is committed to (added as a new item with the
next free ID in its section).
- A deferred item is taken up (status moves from `[~]` to `[ ]`).
- An item is satisfied (status moves to `[x]`, with a reference
to the commit, PR, or test that demonstrates it).
- An item moves out of scope (status moves to `[-]` with a
rationale and a link to the decision).
IDs are stable: once assigned, they are not reused. Removing a
requirement leaves a "withdrawn" entry referencing the decision.