Isolate compiled SQL fragment caches by compiler instance

[fubhy]

Summary

Compiling the same fragment with a second compiler can return SQL and placeholders generated by the first compiler's dialect.

Closes EFF-434

Important

This PR starts with focused failing reproduction tests. Add the implementation fix to this same branch; CI is expected to fail until that fix is included.

Fragment compilation cache crosses SQL dialects

Module: Statement
Audit ID: unstable-services-statement-compiler-cache
Severity / confidence: high / high

What happens

Compiling the same fragment with a second compiler can return SQL and placeholders generated by the first compiler's dialect.

Why it happens

The compiled tuple is cached directly on the fragment under a global symbol per transform mode, without isolating entries by compiler instance.

Expected behavior

Compiler.compile must use the receiving compiler's dialect, identifier transform, placeholders, and custom handlers.

Relevant implementation

These links and excerpts are pinned to audit base c9b56ab507f224426ee8388dc450da447ec4715f.

• packages/effect/src/unstable/sql/Statement.ts:815-830
• packages/effect/src/unstable/sql/Statement.ts:1032-1036

View problematic code at packages/effect/src/unstable/sql/Statement.ts:815-830

const statementCacheSymbol = Symbol.for("effect/unstable/sql/Statement/statementCache")
const statementCacheNoTransformSymbol = Symbol.for("effect/unstable/sql/Statement/statementCacheNoTransform")

const CompilerProto = {
  compile(
    this: CompilerImpl,
    statement: Fragment,
    withoutTransform = false,
    placeholderOverride?: (u: unknown) => string
  ): readonly [sql: string, binds: ReadonlyArray<unknown>] {
    const opts = this.options
    withoutTransform = withoutTransform || this.disableTransforms
    const cacheSymbol = withoutTransform ? statementCacheNoTransformSymbol : statementCacheSymbol
    if (cacheSymbol in statement) {
      return (statement as any)[cacheSymbol]
    }

View exact lines on GitHub

View problematic code at packages/effect/src/unstable/sql/Statement.ts:1032-1036

    const result = [sql, binds] as const
    if (placeholderOverride !== undefined) {
      return result
    }
    return (statement as any)[cacheSymbol] = result

View exact lines on GitHub

Reproduction

pnpm test --run packages/effect/test/unstable/sql/Statement.test.ts

Observed failure: FAIL: SQLite compilation returned PostgreSQL SQL with a $1 placeholder.

Implementation handoff

The initial reproduction tests on this branch are the regression specification for the implementation fix that should follow in this PR.

1. Start with the pinned implementation excerpts and the Why it happens analysis above.
2. Change the implementation so it satisfies the stated Expected behavior; do not weaken or remove the reproduction assertions.
3. Run the focused reproduction command(s) and confirm the observed failures become passing tests:

pnpm test --run packages/effect/test/unstable/sql/Statement.test.ts

4. Run the affected package's existing tests, then the repository lint and type checks before requesting review.

Audit provenance

• Audit base: c9b56ab507f224426ee8388dc450da447ec4715f
• Reproduction base: c9b56ab507f224426ee8388dc450da447ec4715f
• Findings: unstable-services-statement-compiler-cache
• Initial patch: focused reproduction tests; implementation fix pending

[changeset-bot]

🦋 Changeset detected

Latest commit: af685f2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 30 packages

Name	Type
effect	Patch
@effect/opentelemetry	Patch
@effect/platform-browser	Patch
@effect/platform-bun	Patch
@effect/platform-deno	Patch
@effect/platform-node-shared	Patch
@effect/platform-node	Patch
@effect/vitest	Patch
@effect/ai-anthropic	Patch
@effect/ai-openai-compat	Patch
@effect/ai-openai	Patch
@effect/ai-openrouter	Patch
@effect/atom-react	Patch
@effect/atom-solid	Patch
@effect/atom-vue	Patch
@effect/sql-clickhouse	Patch
@effect/sql-d1	Patch
@effect/sql-libsql	Patch
@effect/sql-mssql	Patch
@effect/sql-mysql2	Patch
@effect/sql-pg	Patch
@effect/sql-pglite	Patch
@effect/sql-sqlite-bun	Patch
@effect/sql-sqlite-do	Patch
@effect/sql-sqlite-node	Patch
@effect/sql-sqlite-react-native	Patch
@effect/sql-sqlite-wasm	Patch
@effect/docgen	Patch
@effect/doctest	Patch
@effect/openapi-generator	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pullfrog]

Important

The PR title and commit message say the cache isolation is implemented, but the diff only adds the failing regression test. The source fix in packages/effect/src/unstable/sql/Statement.ts is still missing, so CI fails as expected. Please add the compiler-instance-scoped cache before merging.

Reviewed changes

• Added a regression test in packages/effect/test/unstable/sql/Statement.test.ts that demonstrates the bug: compiling the same fragment first with a PostgreSQL compiler and then with a SQLite compiler returns PostgreSQL placeholders ($1) from the global fragment cache.

• The test currently fails against main because CompilerProto.compile stores compiled results under global Symbol.for keys on the fragment itself, so every compiler instance shares the same cache slot.

  ^{｜ ⚠️ this action is pinned to a commit SHA, which freezes the cleanup step — switch to @v0 or keep the SHA fresh with Dependabot ｜ Fix all ➔ ｜ Fix 👍s ➔ ｜ View workflow run ｜ Using Kimi K2 (free via Pullfrog for OSS) ｜ 𝕏}

.

[pullfrog]

✅ No new issues found. The compiler-instance cache isolation is implemented correctly and the regression test passes.

Reviewed changes

• Replaced the global Symbol.for cache slots on Fragment with per-compiler WeakMap<Fragment, CompiledStatement> instances (statementCache and statementCacheNoTransform) in packages/effect/src/unstable/sql/Statement.ts.
• Updated CompilerProto.compile to read from and write to the compiler-scoped cache, preserving the existing placeholderOverride bypass.
• The regression test in packages/effect/test/unstable/sql/Statement.test.ts now passes: compiling the same fragment with PostgreSQL and SQLite compilers returns the correct dialect-specific placeholders ($1 vs ?).
• Added a concise effect patch changeset at .changeset/isolate-sql-compiler-cache.md.

The prior review thread about the missing implementation has been resolved.

  ^{｜ ⚠️ this action is pinned to a commit SHA, which freezes the cleanup step — switch to @v0 or keep the SHA fresh with Dependabot ｜ View workflow run ｜ Using Kimi K2 (free via Pullfrog for OSS) ｜ 𝕏}

[github-actions]

Bundle Size Analysis

Generated from PR build output; treat the content below as untrusted.

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