From 844e004f25ec4b89376b4d62aea735318393be9d Mon Sep 17 00:00:00 2001
From: Petri Lehtinen <petri@digip.org>
Date: Wed, 16 Mar 2022 22:09:00 +0200
Subject: [PATCH] Make it possible to move routes under a prefix again

---
 README.md                                 |  5 +++++
 docs/upgrading.md                         | 18 ++++++++++++++++--
 src/generate.ts                           | 13 +++++++++++--
 tests/__snapshots__/generate.spec.ts.snap |  2 +-
 tests/other-routes.ts                     |  1 +
 5 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 28a4d6c4..3eb4165b 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,12 @@ const myRoute: Route<Response.Ok<MyResult> | Response.BadRequest<string>> =
 
 // ...
 
+/**
+ * @prefix /api
+ */
 export default router(myRoute, ...)
+
+// The optional @prefix JSDoc tag prepends the prefix to all route paths.
 ```
 
 Run the `typera-openapi` tool giving paths to your route files as command line
diff --git a/docs/upgrading.md b/docs/upgrading.md
index ae96e048..53db4534 100644
--- a/docs/upgrading.md
+++ b/docs/upgrading.md
@@ -60,14 +60,28 @@ const openapiDoc: OpenAPIV3.Document = {
     version: '0.1.0',
   },
   paths: {
-    ...routeDefs.paths,
-    ...otherDefs.paths
+    ...prefix('/api', routeDefs.paths),
+    ...prefix('/other', otherDefs.paths),
   }
 }
 ```
 
 New:
 
+Use the `@prefix` JSDoc tag to move routes to a different prefix:
+
+`routes.ts`
+
+```
+/**
+ * @prefix /api
+ */
+export default router(myRoute, ...)
+```
+
+The file that has the final OpenAPI document doesn't need to use the `prefix`
+function anymore:
+
 ```
 import openapi from './openapi'
 
diff --git a/src/generate.ts b/src/generate.ts
index 60399bc0..9d619c37 100644
--- a/src/generate.ts
+++ b/src/generate.ts
@@ -70,6 +70,8 @@ const visitTopLevelNode = (
   node: ts.Node
 ): OpenAPIV3.PathsObject | undefined => {
   if (ts.isExportAssignment(node) && !node.isExportEquals) {
+    const prefix = getRouterPrefix(node)
+
     // 'export default' statement
     const argSymbols = getRouterCallArgSymbols(ctx, node.expression)
     if (!argSymbols) return
@@ -96,9 +98,10 @@ const visitTopLevelNode = (
       )
       if (routeDeclaration) {
         const [path, method, operation] = routeDeclaration
-        const pathsItemObject = paths[path]
+        const prefixedPath = prefix + path
+        const pathsItemObject = paths[prefixedPath]
         if (!pathsItemObject) {
-          paths[path] = { [method]: operation }
+          paths[prefixedPath] = { [method]: operation }
         } else {
           pathsItemObject[method] = operation
         }
@@ -213,6 +216,12 @@ const getRouteTags = (symbol: ts.Symbol): string[] | undefined =>
     .flatMap((symbolDisplayPart) => symbolDisplayPart.text.split(','))
     .map((tag) => tag.trim())
 
+const getRouterPrefix = (node: ts.Node): string =>
+  ts
+    .getJSDocTags(node)
+    .filter((tag) => tag.tagName.escapedText === 'prefix')
+    .flatMap((tag) => (typeof tag.comment === 'string' ? [tag.comment] : []))[0] ?? ''
+
 const operationRequestBody = (
   contentSchema: OpenAPIV3.SchemaObject | OpenAPIV3.ReferenceObject | undefined,
   contentType = 'application/json'
diff --git a/tests/__snapshots__/generate.spec.ts.snap b/tests/__snapshots__/generate.spec.ts.snap
index 75733dde..44688eff 100644
--- a/tests/__snapshots__/generate.spec.ts.snap
+++ b/tests/__snapshots__/generate.spec.ts.snap
@@ -399,7 +399,7 @@ Object {
         },
       },
     },
-    "/other-route": Object {
+    "/other-stuff/other-route": Object {
       "get": Object {
         "responses": Object {
           "200": Object {
diff --git a/tests/other-routes.ts b/tests/other-routes.ts
index 0b6587bb..a61ffd3b 100644
--- a/tests/other-routes.ts
+++ b/tests/other-routes.ts
@@ -2,4 +2,5 @@ import { Response, route, Route, router } from 'typera-express'
 
 const otherRoute: Route<Response.Ok<string>> = route.get('/other-route').handler(() => Response.ok('hello'))
 
+/** @prefix /other-stuff */
 export default router(otherRoute)