fix: don't use custom parsing for simple cases

Author: mnahkies

packages/openapi-code-generator/src/core/openapi-types-normalized.ts

@@ -142,7 +142,7 @@ export interface IRParameterPath extends IRParameterBase {
 export interface IRParameterQuery extends IRParameterBase {
   in: "query"
   style: "form" | "spaceDelimited" | "pipeDelimited" | "deepObject" // default: form
-  explode: boolean | undefined // default: true for form/cookie, false for other styles
+  explode: boolean // default: true for form/cookie, false for other styles
   allowEmptyValue: boolean //default: false
 }
 

packages/openapi-code-generator/src/typescript/server/server-operation-builder.ts

@@ -62,6 +62,7 @@ export type Parameters = {
     schema: string | undefined
     type: string
     parameters: QueryParameter[]
+    isSimpleQuery: boolean
   }
   header: {
     name: string
@@ -198,6 +199,7 @@ export class ServerOperationBuilder {
 
   private queryParameters(): Parameters["query"] {
     const $ref = this.operation.parameters.query.$ref
+    const parameters = this.operation.parameters.query.list
 
     const schema = $ref
       ? this.schemaBuilder.fromModel(this.input.schema($ref), true, true)
@@ -210,18 +212,25 @@ export class ServerOperationBuilder {
     }
 
 
+    const reflectionParameters = parameters.map((it) => ({
+      name: it.name,
+      explode: it.explode,
+      style: it.style,
+      schema: this.queryParameterRuntimeSchema(this.input.schema(it.schema)),
+    }))
+
+    // When all the query parameters are primitives, we don't need to do custom parsing, as server frameworks
+    // will already parse them naively.
+    const isSimpleQuery = reflectionParameters.every(
+      (it) => it.schema.type !== "object" && it.schema.type !== "array",
+    )
+
     return {
       name: this.operation.parameters.query.name,
       schema: schema,
       type,
-      parameters: this.operation.parameters.query.list.map((it) => ({
-        name: it.name,
-        // todo: only default true when style: form
-        // todo: remove defaulting - normalization does this
-        explode: it.explode ?? true,
-        style: it.style ?? "form",
-        schema: this.queryParameterRuntimeSchema(this.input.schema(it.schema)),
-      })),
+      parameters: reflectionParameters,
+      isSimpleQuery,
     }
   }
 

packages/openapi-code-generator/src/typescript/server/typescript-express/typescript-express-router-builder.ts

@@ -143,7 +143,7 @@ router.${builder.method.toLowerCase()}(\`${builder.route}\`, async (req: Request
   try {
    const input = {
     params: ${params.path.schema ? `parseRequestInput(${params.path.name}, req.params, RequestInputType.RouteParam)` : "undefined"},
-    query: ${params.query.schema ? `parseRequestInput(${params.query.name}, parseQueryParameters(new URL(\`http://localhost\${req.originalUrl}\`).search, ${JSON.stringify(params.query.parameters)}), RequestInputType.QueryString)` : "undefined"},
+    query: ${params.query.schema ? `parseRequestInput(${params.query.name}, ${params.query.isSimpleQuery ? `req.query` : `parseQueryParameters(new URL(\`http://localhost\${req.originalUrl}\`).search, ${JSON.stringify(params.query.parameters)})`}, RequestInputType.QueryString)` : "undefined"},
     ${params.body.schema && !params.body.isSupported ? `// todo: request bodies with content-type '${params.body.contentType}' not yet supported\n` : ""}body: ${params.body.schema ? `parseRequestInput(${params.body.schema}, req.body, RequestInputType.RequestBody)${!params.body.isSupported ? " as never" : ""}` : "undefined"},
     headers: ${params.header.schema ? `parseRequestInput(${params.header.name}, req.headers, RequestInputType.RequestHeader)` : "undefined"}
    }

packages/openapi-code-generator/src/typescript/server/typescript-koa/typescript-koa-router-builder.ts

@@ -146,7 +146,7 @@ const ${symbols.responseBodyValidator} = ${builder.responseValidator()}
 router.${builder.method.toLowerCase()}('${symbols.implPropName}','${builder.route}', async (ctx, next) => {
    const input = {
     params: ${params.path.schema ? `parseRequestInput(${params.path.name}, ctx.params, RequestInputType.RouteParam)` : "undefined"},
-    query: ${params.query.schema ? `parseRequestInput(${params.query.name}, parseQueryParameters(ctx.querystring, ${JSON.stringify(params.query.parameters)}), RequestInputType.QueryString)` : "undefined"},
+    query: ${params.query.schema ? `parseRequestInput(${params.query.name}, ${params.query.isSimpleQuery ? "ctx.query" : `parseQueryParameters(ctx.querystring, ${JSON.stringify(params.query.parameters)})`}, RequestInputType.QueryString)` : "undefined"},
     ${params.body.schema && !params.body.isSupported ? `// todo: request bodies with content-type '${params.body.contentType}' not yet supported\n` : ""}body: ${params.body.schema ? `parseRequestInput(${params.body.schema}, Reflect.get(ctx.request, "body"), RequestInputType.RequestBody)${!params.body.isSupported ? " as never" : ""}` : "undefined"},
     headers: ${params.header.schema ? `parseRequestInput(${params.header.name}, Reflect.get(ctx.request, "headers"), RequestInputType.RequestHeader)` : "undefined"}
    }