feat: unqualified column completion inferred from the FROM clause

[mscolnick]

Summary

Typing a bare identifier prefix now completes columns of the tables referenced in the current statement's FROM/JOIN clauses — even when the schema defines many tables:

SELECT id, name, email
FROM users
WHERE active = true
ORDER BY created_at DESC;

SELECT e → email, ORDER BY cre → created_at, because FROM users is in the statement.

Previously unqualified column completion was delegated entirely to @codemirror/lang-sql's schemaCompletionSource, which only offers top-level columns when a single defaultTable is configured — impossible with 2+ tables/schemas.

Changes

• New unqualifiedColumnCompletionSource({ schema?, parser?, contextAnalyzer? }) (src/sql/column-completion-source.ts):
  • Matches bare identifier prefixes; skips qualified paths (after a dot — the alias source's territory) and table-name positions (right after FROM/JOIN/INTO/UPDATE/TABLE)
  • Scopes to the statement under the cursor; reuses QueryContextAnalyzer (AST walk + regex fallback, so it works mid-edit on unparsable SQL)
  • Offers the union of all FROM/JOIN tables' columns with detail: "column of <table>"; duplicate names across joins appear once
  • CTEs in FROM resolve to their declared/inferred columns; under-qualified tables that are ambiguous across schemas yield nothing rather than wrong columns
  • Empty prefix completes only on explicit (Ctrl-Space) requests; columns get a small boost to rank just above keywords
• src/sql/completion-utils.ts: resolveSchema / findTableColumns / toCompletion lifted unchanged from the alias source and shared by both (no behavior change to aliasColumnCompletionSource)
• Exported from src/index.ts, registered in the demo (sharing one QueryContextAnalyzer across completion sources), documented in README

Test plan

• 18 new tests in src/sql/__tests__/column-completion-source.test.ts: the motivating multi-table scenario, ORDER BY, joins + per-table details, dedup, dot/table-position guards, empty prefix, mid-edit SQL, multi-statement scoping, aliased/quoted/nested tables, ambiguity, CTEs, facet fallback, boosts
• pnpm test (412 passed), pnpm run typecheck, pnpm exec oxlint, pnpm run demo all clean

---

Summary by cubic

Adds FROM-aware autocomplete for bare column prefixes. Typing unqualified text like SELECT e now suggests columns from tables in the current statement, including joins and CTEs, with better multi‑schema support than @codemirror/lang-sql.

• New Features

  • Add unqualifiedColumnCompletionSource({ schema?, parser?, contextAnalyzer? }).
  • Completes in SELECT/WHERE/ORDER BY; skips after a dot and in table-name positions; empty prefix only on explicit request.
  • Unions columns from FROM/JOIN tables; de-dupes; shows "column of "; supports CTE columns; small boost over keywords; falls back to sqlSchemaFacet; preserves schema-provided boosts.

  • Bug Fixes

    • No suggestions inside string literals or comments.
    • Skip in comma-continued FROM table lists; still completes after commas in SELECT/GROUP BY.
    • Correctly resolves quoted table names containing dots (e.g. "my.table").

  ^{Written for commit 6510749. Summary will update on new commits.}

  

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Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	90.92%	1653 / 1818
🔵	Statements	91.08%	1726 / 1895
🔵	Functions	94.69%	232 / 245
🔵	Branches	82.58%	1290 / 1562

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
src/index.ts	0%	0%	0%	0%
src/sql/alias-completion-source.ts	100%	88%	100%	100%
src/sql/column-completion-source.ts	96.61%	85.36%	100%	96.42%	72, 119
src/sql/completion-utils.ts	89.47%	77.77%	100%	87.87%	18, 23, 61, 70
src/sql/namespace-utils.ts	93.41%	78.39%	100%	93.33%	147, 156-168, 262, 317-333

Generated in workflow #653 for commit 991e53a by the Vitest Coverage Report Action

[cubic-dev-ai]

All reported issues were addressed across 8 files

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