PgTidy/docs/todo.md

# PgTidy — TODO / Progress

Tracks what is done and what remains. See `plan.md` for the full design and rationale.

Legend: ✅ done · 🚧 in progress · ⬜ not started

---

## V1 — Formatter + CLI (current milestone)

### ✅ Scaffold module + repo hygiene
- `go.mod` (`module git.warky.dev/wdevs/pgtidy`, go 1.26).
- Replaced WkMailSync boilerplate: `AGENTS.md` (PgTidy architecture + invariants),
  `CLAUDE.md`, `Makefile` (`build`/`test`/`vet`/`fmt`/`lint`/`clean`).
- Directory layout created (`cmd/`, `pkg/...`, `testdata/`).
- Copied 4 real-world procedures into `testdata/corpus/*.pgsql` (safety harness).

### ✅ Lossless lexer — `pkg/lexer`
- `token.go`: `Kind` enum (trivia, words, literals, operators, punctuation) + `Token`.
- `lexer.go`: full PG token coverage — dollar-quoted strings (`$tag$`, nested-tag aware),
  `--` / nestable `/* */` comments, standard/escape/bit/hex/unicode strings,
  numbers (decimal, exponent, leading dot, `0x/0o/0b`, `_` separators), positional params
  (`$1`), operator runs with PostgreSQL's trailing `+/-` rule, `::` / `:=` / `:`, punctuation.
  Tracks line/col per token.
- `lexer_test.go`: unit tests (kinds, operator trailing rule, dollar quotes, line/col) +
  **corpus round-trip** asserting `emit(Lex(src)) == src` byte-for-byte.
- **Status:** all tests pass; round-trips all 4 corpus files. Invariant #1 satisfied.

### ✅ CST node model + parser — `pkg/cst`, `pkg/parser`
- `pkg/cst`: lossless node model — `Tok` (significant token + leading trivia), `Attach`,
  `File.Source()` (byte-exact reconstruction), `Raw` (verbatim fallback), `CreateFunction`
  (Head/Name/Params/Options/As/Body/Tail/Semi), `Param` (with separator comma).
- `pkg/parser`: statement splitting at top-level `;`; structures CREATE FUNCTION/PROCEDURE
  (head, qualified name, comma-split params, option clauses split by keyword, AS + body);
  everything else → `Raw`. Graceful degradation is a property of the data model.
- `parser_test.go`: small round-trips, CreateFunction shape assertions, Raw fallback, and
  **corpus round-trip** — reconstructs all 4 files byte-for-byte; structures all 4 functions.
- **Status:** all tests pass.
- _Still TODO (later): DML/other-DDL structuring (currently Raw) for full formatting._

### 🚧 PL/pgSQL body parser  ← NEXT (the remaining V1 piece)

#### ✅ DECLARE section — `pkg/format/body.go`
- `formatBody` splits the dollar-quote tag, calls `formatBodyInner`.
- `formatBodyInner` locates `DECLARE` and `BEGIN` at depth 0, formats the declare block,
  then emits `BEGIN` onwards verbatim.
- `formatDeclareVars`: each variable declaration collapsed to one line
  (`  name type [= expr];`), `--Block--` comment markers preserved on their own lines,
  mid-declaration block comments trigger verbatim fallback.
- `needSpace` fixed for `LBracket` — no space before `[` after ident/closing bracket
  (fixes `citext[]`, array subscripts).
- `semanticallyEqual` in tests updated to recurse into dollar-quoted body tokens so
  whitespace normalization inside the body does not falsely fail the semantic check.
- Added `testdata/corpus/test_a_broken.pgsql` — a CRLF corpus file with intentionally
  broken layout (split-line variables + split-line body statements) used as a formatting
  target; `testdata/corpus/test_a.pgsql` is the golden output.
- **Status:** all tests pass; DECLARE section formats correctly.

#### ✅ Body statement formatter — `pkg/format/body.go`
- `formatBodyStatements`: line-by-line formatter for the `BEGIN … END` block.
- Block-depth tracker: `BEGIN`/`END`, `IF`/`THEN`/`ELSIF`/`ELSE`/`END IF`, `LOOP`/`END LOOP`, `EXCEPTION`.
- Split-line join: col-0 lines at paren-depth 0 with non-clause first token are joined to preceding line. SQL clause keywords (`SELECT`, `FROM`, `WHERE`, `INTO`, `WITH`, `HAVING`, `GROUP`, `ORDER`, `RETURNING`, `SET`, joins) stay on own lines.
- Base-indent normalisation: first logical line of each statement gets `blockDepth × st.Indent`; subsequent lines preserve their original indentation (relative indentation maintained for multi-line expressions).
- Blank-line count preservation: blank lines between statements kept as-is.
- Verbatim-indent mode after `EXCEPTION`: original leading whitespace preserved to avoid style conflicts between functions that put `WHEN` at col-0 vs indented.
- `sqlClauseKw` map; `firstBodyKeyword`, `leadingWhitespace` helpers.
- `TestFormatBodyBroken`: golden-file test — `format(test_a_broken.pgsql)` must equal `test_a.pgsql`.
- Updated `test_a.pgsql` to match actual formatter output.
- **Status:** all tests pass; idempotence verified.

### ✅ Printer + style config — `pkg/format`, `pkg/config`
- `pkg/config`: `Style` struct + `Default()` = house style. `Load(startDir)` walks up the
  directory tree to find `.pgtidy.yaml` and merges its fields over the defaults.
  Supported keys: `indent`, `newline`, `keyword_case`, `ident_case`, `type_case`, `commas`.
  Dependency: `gopkg.in/yaml.v3`.
- `pkg/format`: formats CREATE FUNCTION/PROCEDURE **headers** to house style (params
  one-per-line leading-comma, option clauses each on own line, AS/`$$` own lines); DECLARE
  section formatted (see body parser entry); `Raw` statements emitted verbatim.
  Spacing engine (`needSpace`, tight ops `:: : -> ->>`, array `[]`) + casing
  (`keywords`/`typeNames` sets). Comment-safety: verbatim fallback if a header carries
  comments it cannot relocate.
- `pkg/format/body.go`: DECLARE section formatter (see body parser entry).
- Tests: golden header, idempotence, corpus idempotence + **semantic equivalence**
  (updated to recurse into dollar-quoted body tokens).
- _Note: not a full Wadler Doc-IR yet — fixed-layout printer. Doc-IR for width-based
  expression wrapping can come when DML structuring lands._

### ✅ CLI `fmt` + safety harness — `cmd/pgtidy`
- `pgtidy fmt` (gofmt model): default stdin→stdout; `-w`/`--write`, `-l`/`--list`,
  `--check` (CI exit codes); `-d`/`--diff` (unified diff output); `version`/`help`.
- Config discovery: walks up from cwd to find `.pgtidy.yaml`; applied before formatting.
- `diff.go`: in-house unified diff (LCS-based, zero additional deps).
- `fmt_test.go`: stdin, --check (un/formatted), -w idempotence, unknown-command.
- Safety invariants #2 (semantic equivalence), #3 (idempotence), #4 (graceful degradation)
  are tested in `pkg/format` over the corpus.

---

## ✅ V2 — Linter
- `pkg/pgast`: `go-pgquery` (WASM, no cgo) wrapper → real PG AST. `FirstTokenOffset`
  skips leading whitespace/comments for accurate line numbers.
- `pkg/diagnostics`: `Diagnostic{RuleID, Severity, Message, File, Line, Col}`.
- `pkg/lint`: `Engine`, `Rule` interface, `New()` with all built-ins:
  - MIG001 CREATE INDEX without CONCURRENT
  - MIG002 ALTER TABLE ADD COLUMN NOT NULL without DEFAULT
  - MIG003 ALTER TABLE ADD CONSTRAINT FK/CHECK without NOT VALID
  - COR001 SELECT *  |  COR002 UPDATE without WHERE  |  COR003 DELETE without WHERE
  - NAM001/2/3 table/column/function names not snake_case (quoted identifiers only)
- `pgtidy lint [--only=ID,...] [files...]`; exits 1 on findings, 2 on error.
- Fixture SQL in `testdata/lint/`; 6 tests covering violations + clean fixtures.
- `--fix` rewrites files in place applying autofixes; for stdin, prints fixed SQL to stdout.
- Autofixable: **MIG001** (insert `CONCURRENTLY` after `INDEX`) and **MIG003** (insert `NOT VALID` before `;`). MIG002, COR*, NAM* are intentionally not autofixable.
- `pkg/diagnostics.TextFix{Offset, End, New, Title}` — byte-range replacement attached to `Diagnostic.Fix`.
- `pkg/lint.ApplyFixes` — applies all fixes in reverse-offset order; overlapping fixes skipped.
- Fix helpers (`mig001Fix`, `mig003Fix`) handle pg_query's convention of `StmtLen` excluding the trailing `;`.

## ✅ V3 — LSP + VSCode
- `pkg/lsp`: JSON-RPC 2.0 over stdio; `textDocument/formatting` (full document), `publishDiagnostics` on every open/change, `textDocument/codeAction` quick-fixes, lifecycle (initialize/shutdown/exit). No external deps.
- `cmd/pgtidy/lsp.go`: `pgtidy lsp` subcommand; config discovered from cwd.
- `editors/vscode/`: TS extension using `vscode-languageclient`; launches `pgtidy lsp` via stdio; `.pgsql` mapped to `sql` language; `pgtidy.path` / `pgtidy.enable` settings.
- _Range formatting: future._

## ✅ V4 — DataGrip
- `editors/datagrip/`: Gradle-based JetBrains plugin targeting DataGrip 2024.3+ via LSP4IJ.
  - `build.gradle.kts` / `settings.gradle.kts` / `gradle.properties` — IntelliJ Platform Gradle Plugin v2.
  - `plugin.xml` — registers `PgTidyServerFactory` as an LSP4IJ `<server>` extension and maps `*.sql`/`*.pgsql` to it.
  - `PgTidyServerFactory.kt` + `PgTidyServerConnection.kt` — launches `pgtidy lsp` via `ProcessStreamConnectionProvider`.
  - Requires LSP4IJ plugin installed in the IDE; `pgtidy` binary on PATH.

---

## ✅ Build / release (cross-cutting)
- `.goreleaser.yaml`: multi-platform matrix — linux/darwin × amd64/arm64 + windows/amd64; no CGO; ldflags version injection; draft GitHub release.
- `Makefile` extended: `snapshot` (local multi-platform build), `release` (publish), `vscode-compile`, `vscode-package`.
- `.github/workflows/ci.yml`: test + vet + gofmt check + goreleaser snapshot on every push/PR.
- `.github/workflows/release.yml`: goreleaser publish + VSCode `.vsix` artifact on `v*` tag.
- `make_release.sh` retained from boilerplate.

## Core invariants (must always hold — tested)
1. ✅ Lossless lex: `emit(Lex(src)) == src` (corpus round-trip).
2. ✅ Semantic equivalence: formatting changes only trivia/layout (corpus token-stream check).
3. ✅ Idempotence: `fmt(fmt(x)) == fmt(x)` (corpus + CLI tests).
4. ✅ Graceful degradation: unparsable spans pass through verbatim (Raw nodes + verbatim body).

## ✅ DML statement formatting (top-level)
- `pkg/format/dml.go`: `formatDML` formats top-level SELECT/INSERT/UPDATE/DELETE/WITH.
- Clause-per-line layout at depth-0 boundaries; handles: SELECT, FROM, WHERE, HAVING,
  GROUP BY, ORDER BY, LIMIT, OFFSET, RETURNING, JOIN variants (LEFT/RIGHT/INNER/FULL/
  CROSS/NATURAL, optional OUTER), ON CONFLICT, UNION/INTERSECT/EXCEPT, SET, VALUES,
  INSERT INTO, DELETE FROM, WITH (including multi-CTE bodies).
- SELECT, SET, and RETURNING bodies formatted as leading-comma column lists.
- Keywords inside subqueries (paren depth > 0) cased correctly via `dmlInline`.
- `needSpace`: added `parenKws` set (AS, EXISTS, IN, NOT, LIKE, ILIKE, SIMILAR) so
  these keywords get a space before `(` instead of the no-space function-call rule.
- Printer `writeItem`: detects DML-starting Raw nodes and routes to `formatDML`.
- Tests: 13 targeted golden tests + idempotence sweep in `pkg/format/dml_test.go`.
- Note: table name before `(` in INSERT column list is indistinguishable from a
  function call at the token level — formatted without space (known limitation).
- Note: SQL keywords inside PL/pgSQL function bodies remain lowercase (matching
  the corpus golden files); casing is applied only to top-level DML.
- _Still TODO: Wadler Doc-IR printer for width-aware wrapping of long lines._
- _Still TODO: LSP range formatting._

## Open risks
- `go-pgquery` tracks PG17 (not PG18) — fine for lint; irrelevant to formatter path.
- Leading-comma + one-per-line is a first-class style option, not an afterthought.