fix(codegen-ts): emit JS array literal for isArray @default (TS2345)#146
Merged
Conversation
A downstream adopter upgrading to 0.15.1 hit non-compiling Drizzle output for
an array field with a default, e.g. `field.string { isArray: true,
default: "{}" }`. The pg entity generator emitted
`text("conditions").array().notNull().default("{}")`, which fails `tsc` with
TS2345 — Drizzle's `.array().default(x)` wants `string[] | SQL`, not a string.
The same shape broke SQLite (`.$type<E[]>().default("{}")`).
Root cause: pre-0.15.0 an isArray string field mapped to jsonb, where
`.default("[]")` was valid. The 0.15.0 @dbColumnType slim-and-derive (ADR-0036)
made isArray emit a native text[] (`.array()`) column, but the default-emitter
still passed the raw @default string through.
Fix (codegen-ts only — the Java loader requires @default to be a string, so an
array default MUST be authored as "[]"/"{}"; it cannot be fixed in metadata):
parse the metadata default string for a scalar isArray field into a real JS
array literal via a new `{ kind: "arrayLiteral", elements }` DefaultExpr.
- "{}" / "[]" -> .default([])
- "{a,b}" / '["a","b"]' -> .default(["a", "b"]) (elements quoted per type)
- unsupported/ambiguous shape -> .default(sql`...`) so output ALWAYS
typechecks, never a bare string
Scalar/flat defaults and object/map-array storage are byte-identical.
Tests: shape assertions in column-mapper.test.ts plus a real-tsc compile guard
(array-default-compile.test.ts, mirroring projection/compile.test.ts) that
proves the generated entity typechecks with ZERO diagnostics on both dialects —
it reproduces the exact TS2345 without the fix.
Cross-port note: Java currently ignores array @default (emits none); this fix
is TS-specific, so the fixture is kept TS-local (not in the shared
codegen-conformance corpus).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GF9xLEQZaPus5Y6opk398n
dmealing
pushed a commit
that referenced
this pull request
Jul 2, 2026
npm lockstep to 0.15.2 — codegen-ts isArray @default fix (#146) + cross-language version-drift agent-context guidance (#147). Completes the coordinated patch (Maven 7.7.2 / PyPI 0.15.3 / NuGet 0.15.2). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GF9xLEQZaPus5Y6opk398n
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Problem
A downstream adopter upgrading to 0.15.1 hit non-compiling Drizzle output for an array field with a default. For
field.string { name: conditions, isArray: true, default: "{}" }the pg entity generator emitted:which fails
tscwith TS2345 — Drizzle's.array().default(x)wantsstring[] | SQL<unknown>, not a string. The same shape broke SQLite (.$type<E[]>().default("{}")).Why it regressed at 0.15.0
Before 0.15.0 an
isArraystring field mapped to jsonb, where.default("[]")was valid. The 0.15.0@dbColumnTypeslim-and-derive (ADR-0036) madeisArrayemit a nativetext[](.array()) column, but the default-emitter still passed the raw@defaultstring through. Scalar/flat defaults were unaffected.Why it can't be fixed in metadata
The Java loader requires
@defaultto be a string (default: []fails load), so an array default MUST be authored as a string ("[]"/"{}"). The fix belongs in codegen-ts.Fix
Parse the metadata default string for a scalar
isArrayfield into a real JS array literal, via a new{ kind: "arrayLiteral", elements }DefaultExpr:"{}"/"[]"→.default([])"{a,b}"/'["a","b"]'→.default(["a", "b"])(elements quoted per element type — strings quoted, numerics bare).default(sql\...`)` raw-SQL fallback so the output always typechecks, never a bare stringScalar/flat defaults and object/map-array storage are byte-identical. Emission is dialect-agnostic (works for pg
.array()and sqlite json.$type<E[]>()).Tests
column-mapper.test.ts— shape assertions for{}/[]/{a,b}/JSON-array/int-array/fallback/scalar-unchanged.array-default-compile.test.ts(new) — a real-tsccompile guard (mirrorstest/projection/compile.test.ts) that generates the entity and asserts ZERO TS diagnostics on both dialects. Confirmed it reproduces the exact TS2345 without the fix and passes with it.Verification
bun test packages/codegen-ts→ 987 pass / 0 failbun run --filter '*' typecheck→ clean (whole workspace)Cross-port note
Java currently ignores array
@default(emits none) — this fix is TS-specific, so the fixture is kept TS-local (not added to the sharedcodegen-conformancecorpus). Java array-defaults are a possible follow-up.🤖 Generated with Claude Code
https://claude.ai/code/session_01GF9xLEQZaPus5Y6opk398n