fix(openapi-server): handle explode:true array query params in hono/express routers - #407

packages/openapi-server/src/plugins/router.ts (1)

310-336: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

Minor duplication between Hono/Express array extraction builders.

honoArrayQueryExpr and expressArrayQueryExpr share identical item-coercion suffix logic (?.map(Number) / ?.map((v) => v === 'true')), differing only in the base expression. Could be factored into a shared helper taking the base expression string, reducing duplication if a third item type is added later.

♻️ Optional refactor: extract shared coercion suffix

+function withArrayItemCoercion(base: string, itemsTsType: string | undefined): string {
+  if (itemsTsType === 'number') return `${base}?.map(Number)`
+  if (itemsTsType === 'boolean') return `${base}?.map((v) => v === 'true')`
+  return base
+}
+
 function honoArrayQueryExpr(q: QueryParam): string {
-  const base = `c.req.queries('${q.rawName}')`
-  if (q.itemsTsType === 'number') return `${base}?.map(Number)`
-  if (q.itemsTsType === 'boolean') return `${base}?.map((v) => v === 'true')`
-  return base
+  return withArrayItemCoercion(`c.req.queries('${q.rawName}')`, q.itemsTsType)
 }

 function expressArrayQueryExpr(q: QueryParam): string {
-  const base = `_toQueryArray(req.query['${q.rawName}'] as string | string[] | undefined)`
-  if (q.itemsTsType === 'number') return `${base}?.map(Number)`
-  if (q.itemsTsType === 'boolean') return `${base}?.map((v) => v === 'true')`
-  return base
+  return withArrayItemCoercion(
+    `_toQueryArray(req.query['${q.rawName}'] as string | string[] | undefined)`,
+    q.itemsTsType
+  )
 }

Correctness-wise this segment is solid: boolean items are pre-coerced to real booleans (matching z.boolean(), not .coerce), and number items pre-coerced via Number() combined with z.coerce.number() on the Zod side correctly rejects invalid input (Zod rejects NaN for z.number()/z.coerce.number()).

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@packages/openapi-server/src/plugins/router.ts` around lines 310 - 336, The
Hono and Express array query extraction helpers duplicate the same item-coercion
logic, so factor the shared `?.map(Number)` / `?.map((v) => v === 'true')`
suffix into a common helper and keep `honoArrayQueryExpr` and
`expressArrayQueryExpr` focused on only building their base query expression.
Use the existing symbols `honoArrayQueryExpr`, `expressArrayQueryExpr`, and
`QueryParam` to introduce a small shared helper that takes the base expression
string plus `itemsTsType`, then have both functions delegate to it to reduce
duplication and make future item-type additions easier.

packages/openapi-server/src/__tests__/array-query-typecheck.test.ts (1)

48-80: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

Consider parameterizing the three near-identical it blocks.

Hono/Express/Fastify cases repeat the same generate → compile → assert pattern with only the generator functions differing. A small it.each table would reduce duplication, though the current form is readable and low-risk.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@packages/openapi-server/src/__tests__/array-query-typecheck.test.ts` around
lines 48 - 80, The three test cases in array-query-typecheck.test.ts duplicate
the same generate-compile-assert flow for Hono, Express, and Fastify. Refactor
the repeated `it` blocks into a parameterized table-driven test (for example,
using a single shared helper or `it.each`) that calls the appropriate generators
like `generateService`, `generateRouter`, `generateExpressRouter`,
`generateFastifyTypedService`, and `generateFastifyRouter`, while preserving the
existing compile and `assertNoTsDiagnostics` checks.

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes