From ca56d3c08a2c92e0bd94b6d9b046a42a53b47904 Mon Sep 17 00:00:00 2001
From: Michael Nahkies <michael@nahkies.co.nz>
Date: Sun, 27 Oct 2024 16:43:52 +0000
Subject: [PATCH] feat: emit unique symbol names for `Implementation` /
 `createRouter` functions

- previous names still exported as aliases for backwards compatibility,
  will probably keep these around forever, as sometimes they are more
  convenient

- only occurs when splitting the generated code by tag / slug / etc,
  when outputting a single file the original names are still used for
  now.

relates: #111
---
 e2e/src/generated/routes/headers.ts              |  9 +++++++--
 e2e/src/generated/routes/validation.ts           |  9 +++++++--
 .../openapi-code-generator/src/core/input.ts     |  4 ++--
 .../typescript-koa/typescript-koa.generator.ts   | 16 ++++++++++++++--
 4 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/e2e/src/generated/routes/headers.ts b/e2e/src/generated/routes/headers.ts
index 90c4287e..efe09132 100644
--- a/e2e/src/generated/routes/headers.ts
+++ b/e2e/src/generated/routes/headers.ts
@@ -55,12 +55,14 @@ export type GetHeadersRequest = (
   | Response<200, t_getHeadersRequestJson200Response>
 >
 
-export type Implementation = {
+export type HeadersImplementation = {
   getHeadersUndeclared: GetHeadersUndeclared
   getHeadersRequest: GetHeadersRequest
 }
 
-export function createRouter(implementation: Implementation): KoaRouter {
+export function createHeadersRouter(
+  implementation: HeadersImplementation,
+): KoaRouter {
   const router = new KoaRouter()
 
   const getHeadersUndeclaredResponseValidator = responseValidationFactory(
@@ -153,3 +155,6 @@ export function createRouter(implementation: Implementation): KoaRouter {
 
   return router
 }
+
+export { createHeadersRouter as createRouter }
+export type { HeadersImplementation as Implementation }
diff --git a/e2e/src/generated/routes/validation.ts b/e2e/src/generated/routes/validation.ts
index 36ee3d27..818a1df3 100644
--- a/e2e/src/generated/routes/validation.ts
+++ b/e2e/src/generated/routes/validation.ts
@@ -40,11 +40,13 @@ export type GetValidationNumbersRandomNumber = (
   ctx: RouterContext,
 ) => Promise<KoaRuntimeResponse<unknown> | Response<200, t_RandomNumber>>
 
-export type Implementation = {
+export type ValidationImplementation = {
   getValidationNumbersRandomNumber: GetValidationNumbersRandomNumber
 }
 
-export function createRouter(implementation: Implementation): KoaRouter {
+export function createValidationRouter(
+  implementation: ValidationImplementation,
+): KoaRouter {
   const router = new KoaRouter()
 
   const getValidationNumbersRandomNumberQuerySchema = z.object({
@@ -102,3 +104,6 @@ export function createRouter(implementation: Implementation): KoaRouter {
 
   return router
 }
+
+export { createValidationRouter as createRouter }
+export type { ValidationImplementation as Implementation }
diff --git a/packages/openapi-code-generator/src/core/input.ts b/packages/openapi-code-generator/src/core/input.ts
index f3f1054b..ef844284 100644
--- a/packages/openapi-code-generator/src/core/input.ts
+++ b/packages/openapi-code-generator/src/core/input.ts
@@ -75,7 +75,7 @@ export class Input {
   ): OperationGroup[] {
     switch (strategy) {
       case "none": {
-        return [{name: "generated", operations: this.allOperations()}]
+        return [{name: "", operations: this.allOperations()}]
       }
       case "first-tag":
         return this.operationsByFirstTag()
@@ -154,7 +154,7 @@ export class Input {
 
   private operationsByFirstTag(): OperationGroup[] {
     return this.groupOperations((operation) => {
-      const tag = operation.tags[0] ?? "generated"
+      const tag = operation.tags[0]
 
       if (!tag) {
         throw new Error(
diff --git a/packages/openapi-code-generator/src/typescript/typescript-koa/typescript-koa.generator.ts b/packages/openapi-code-generator/src/typescript/typescript-koa/typescript-koa.generator.ts
index 54ff6da9..115242bf 100644
--- a/packages/openapi-code-generator/src/typescript/typescript-koa/typescript-koa.generator.ts
+++ b/packages/openapi-code-generator/src/typescript/typescript-koa/typescript-koa.generator.ts
@@ -398,20 +398,32 @@ export class ServerRouterBuilder implements ICompilable {
   }
 
   toString(): string {
-    const implementationExportName = "Implementation"
+    const moduleName = titleCase(this.name)
+
+    const implementationExportName = `${moduleName}Implementation`
+    const createRouterExportName = `create${moduleName}Router`
+
     const routes = this.statements
     const code = `
 ${this.operationTypes.flatMap((it) => it.statements).join("\n\n")}
 
 ${this.implementationExport(implementationExportName)}
 
-export function createRouter(implementation: ${implementationExportName}): KoaRouter {
+export function ${createRouterExportName}(implementation: ${implementationExportName}): KoaRouter {
   const router = new KoaRouter()
 
   ${routes.join("\n\n")}
 
   return router
 }
+
+${
+  moduleName &&
+  `
+export {${createRouterExportName} as createRouter}
+export ${this.implementationMethod === "type" || this.implementationMethod === "interface" ? "type" : ""} {${implementationExportName} as Implementation}
+`
+}
 `
     return code
   }