From 14abf27e87d3de52ee7358b109aa278dcd47b7f0 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 13:36:02 +0200
Subject: [PATCH 01/15] feat(fromOpenApi): add possibility to filter oas

---
 src/open-api/from-open-api.ts  | 21 ++++++++++--
 test/oas/from-open-api.test.ts | 59 ++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 test/oas/from-open-api.test.ts

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index d54e506..c4a3ffd 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -11,6 +11,14 @@ const supportedHttpMethods = Object.keys(
   http,
 ) as unknown as SupportedHttpMethods
 
+type PathItemTuple = [
+  url: string,
+  OpenAPIV3.PathItemObject | OpenAPIV2.PathItemObject | undefined,
+]
+export type MapPathItemFunction = (
+  pathItem: PathItemTuple,
+) => PathItemTuple | undefined
+
 /**
  * Generates request handlers from the given OpenAPI V2/V3 document.
  *
@@ -20,6 +28,7 @@ const supportedHttpMethods = Object.keys(
  */
 export async function fromOpenApi(
   document: string | OpenAPI.Document | OpenAPIV3.Document | OpenAPIV2.Document,
+  mapPathItem?: MapPathItemFunction,
 ): Promise<Array<RequestHandler>> {
   const specification = await SwaggerParser.dereference(document)
   const requestHandlers: Array<RequestHandler> = []
@@ -28,8 +37,16 @@ export async function fromOpenApi(
     return []
   }
 
-  const pathItems = Object.entries(specification.paths ?? {})
-  for (const item of pathItems) {
+  const pathItems = Object.entries(
+    specification.paths ?? {},
+  ) as Array<PathItemTuple>
+
+  for (const rowPathItem of pathItems) {
+    const item = mapPathItem ? mapPathItem(rowPathItem) : rowPathItem
+    if (!item) {
+      continue
+    }
+
     const [url, handlers] = item
     const pathItem = handlers as
       | OpenAPIV2.PathItemObject
diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
new file mode 100644
index 0000000..890e4a3
--- /dev/null
+++ b/test/oas/from-open-api.test.ts
@@ -0,0 +1,59 @@
+// @vitest-environment happy-dom
+import {
+  fromOpenApi,
+  MapPathItemFunction,
+} from '../../src/open-api/from-open-api.js'
+import { createOpenApiSpec } from '../support/create-open-api-spec.js'
+import { InspectedHandler, inspectHandlers } from '../support/inspect.js'
+
+it('creates handlers based on provided filter', async () => {
+  const openApiSpec = createOpenApiSpec({
+    paths: {
+      '/numbers': {
+        get: {
+          responses: {
+            200: {
+              content: {
+                'application/json': {
+                  example: [1, 2, 3],
+                },
+              },
+            },
+          },
+        },
+      },
+      '/orders': {
+        get: {
+          responses: {
+            200: {
+              content: {
+                'application/json': {
+                  example: [{ id: 1 }, { id: 2 }, { id: 3 }],
+                },
+              },
+            },
+          },
+        },
+      },
+    },
+  })
+
+  const mapPathItem: MapPathItemFunction = (pathItemTuple) =>
+    pathItemTuple[0] === '/numbers' ? pathItemTuple : undefined
+  const handlers = await fromOpenApi(openApiSpec, mapPathItem)
+
+  expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([
+    {
+      handler: {
+        method: 'GET',
+        path: 'http://localhost/numbers',
+      },
+      response: {
+        status: 200,
+        statusText: 'OK',
+        headers: expect.arrayContaining([['content-type', 'application/json']]),
+        body: JSON.stringify([1, 2, 3]),
+      },
+    },
+  ])
+})

From e1674fb986ab34dd61b540b0777537ac948cd021 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 14:10:40 +0200
Subject: [PATCH 02/15] refactor(fromOpenApi): make mapper function accept 3
 arguments

---
 src/open-api/from-open-api.ts  | 33 ++++++++++++++++-----------------
 test/oas/from-open-api.test.ts | 18 +++++++++++++++---
 2 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index c4a3ffd..7d2c60e 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -11,13 +11,11 @@ const supportedHttpMethods = Object.keys(
   http,
 ) as unknown as SupportedHttpMethods
 
-type PathItemTuple = [
+export type MapOperationFunction = (
   url: string,
-  OpenAPIV3.PathItemObject | OpenAPIV2.PathItemObject | undefined,
-]
-export type MapPathItemFunction = (
-  pathItem: PathItemTuple,
-) => PathItemTuple | undefined
+  method: SupportedHttpMethods,
+  operation: OpenAPIV3.OperationObject,
+) => OpenAPIV3.OperationObject | undefined
 
 /**
  * Generates request handlers from the given OpenAPI V2/V3 document.
@@ -28,7 +26,7 @@ export type MapPathItemFunction = (
  */
 export async function fromOpenApi(
   document: string | OpenAPI.Document | OpenAPIV3.Document | OpenAPIV2.Document,
-  mapPathItem?: MapPathItemFunction,
+  mapOperation?: MapOperationFunction,
 ): Promise<Array<RequestHandler>> {
   const specification = await SwaggerParser.dereference(document)
   const requestHandlers: Array<RequestHandler> = []
@@ -37,16 +35,9 @@ export async function fromOpenApi(
     return []
   }
 
-  const pathItems = Object.entries(
-    specification.paths ?? {},
-  ) as Array<PathItemTuple>
-
-  for (const rowPathItem of pathItems) {
-    const item = mapPathItem ? mapPathItem(rowPathItem) : rowPathItem
-    if (!item) {
-      continue
-    }
+  const pathItems = Object.entries(specification.paths ?? {})
 
+  for (const item of pathItems) {
     const [url, handlers] = item
     const pathItem = handlers as
       | OpenAPIV2.PathItemObject
@@ -60,7 +51,15 @@ export async function fromOpenApi(
         continue
       }
 
-      const operation = pathItem[method] as OpenAPIV3.OperationObject
+      const rowOperation = pathItem[method] as OpenAPIV3.OperationObject
+      if (!rowOperation) {
+        continue
+      }
+
+      const operation = mapOperation
+        ? mapOperation(url, method, rowOperation)
+        : rowOperation
+
       if (!operation) {
         continue
       }
diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 890e4a3..dcc4032 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -1,7 +1,7 @@
 // @vitest-environment happy-dom
 import {
   fromOpenApi,
-  MapPathItemFunction,
+  MapOperationFunction,
 } from '../../src/open-api/from-open-api.js'
 import { createOpenApiSpec } from '../support/create-open-api-spec.js'
 import { InspectedHandler, inspectHandlers } from '../support/inspect.js'
@@ -21,6 +21,17 @@ it('creates handlers based on provided filter', async () => {
             },
           },
         },
+        put: {
+          responses: {
+            200: {
+              content: {
+                'application/json': {
+                  example: [1, 2, 3],
+                },
+              },
+            },
+          },
+        },
       },
       '/orders': {
         get: {
@@ -38,8 +49,9 @@ it('creates handlers based on provided filter', async () => {
     },
   })
 
-  const mapPathItem: MapPathItemFunction = (pathItemTuple) =>
-    pathItemTuple[0] === '/numbers' ? pathItemTuple : undefined
+  const mapPathItem: MapOperationFunction = (url, method, operation) => {
+    return url === '/numbers' && method === 'get' ? operation : undefined
+  }
   const handlers = await fromOpenApi(openApiSpec, mapPathItem)
 
   expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([

From ef6531c9cf51fa0d86174605afa3ed95857f5283 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 14:12:11 +0200
Subject: [PATCH 03/15] refactor(fromOpenApi): change variable name to more
 descriptive one

---
 test/oas/from-open-api.test.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index dcc4032..95e72ae 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -49,10 +49,10 @@ it('creates handlers based on provided filter', async () => {
     },
   })
 
-  const mapPathItem: MapOperationFunction = (url, method, operation) => {
+  const mapOperation: MapOperationFunction = (url, method, operation) => {
     return url === '/numbers' && method === 'get' ? operation : undefined
   }
-  const handlers = await fromOpenApi(openApiSpec, mapPathItem)
+  const handlers = await fromOpenApi(openApiSpec, mapOperation)
 
   expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([
     {

From b3b644ae4b527214928f103baeacbf3fb43d14ba Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 14:14:17 +0200
Subject: [PATCH 04/15] style(fromOpenApi): remove unneeded empty line

---
 src/open-api/from-open-api.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 7d2c60e..1f4821f 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -36,7 +36,6 @@ export async function fromOpenApi(
   }
 
   const pathItems = Object.entries(specification.paths ?? {})
-
   for (const item of pathItems) {
     const [url, handlers] = item
     const pathItem = handlers as

From c49d3c72f9b64a5094faeef752cca7a097d36210 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 14:54:40 +0200
Subject: [PATCH 05/15] refactor(fromOpenApi): use object-as-argument for
 mapper function

---
 src/open-api/from-open-api.ts  | 12 ++++++------
 test/oas/from-open-api.test.ts |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 1f4821f..381d920 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -11,11 +11,11 @@ const supportedHttpMethods = Object.keys(
   http,
 ) as unknown as SupportedHttpMethods
 
-export type MapOperationFunction = (
-  url: string,
-  method: SupportedHttpMethods,
-  operation: OpenAPIV3.OperationObject,
-) => OpenAPIV3.OperationObject | undefined
+export type MapOperationFunction = (args: {
+  url: string
+  method: SupportedHttpMethods
+  operation: OpenAPIV3.OperationObject
+}) => OpenAPIV3.OperationObject | undefined
 
 /**
  * Generates request handlers from the given OpenAPI V2/V3 document.
@@ -56,7 +56,7 @@ export async function fromOpenApi(
       }
 
       const operation = mapOperation
-        ? mapOperation(url, method, rowOperation)
+        ? mapOperation({ url, method, operation: rowOperation })
         : rowOperation
 
       if (!operation) {
diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 95e72ae..8808017 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -49,7 +49,7 @@ it('creates handlers based on provided filter', async () => {
     },
   })
 
-  const mapOperation: MapOperationFunction = (url, method, operation) => {
+  const mapOperation: MapOperationFunction = ({ url, method, operation }) => {
     return url === '/numbers' && method === 'get' ? operation : undefined
   }
   const handlers = await fromOpenApi(openApiSpec, mapOperation)

From c642e1ff2a8aabb4ca4acb68af6d2059ac6ac7c0 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 15:10:43 +0200
Subject: [PATCH 06/15] refactor(fromOpenApi): rename url to path

---
 src/open-api/from-open-api.ts                     | 14 +++++++-------
 src/open-api/utils/normalize-swagger-path.test.ts | 15 +++++++++++++++
 ...e-swagger-url.ts => normalize-swagger-path.ts} |  2 +-
 src/open-api/utils/normalize-swagger-url.test.ts  | 15 ---------------
 test/oas/from-open-api.test.ts                    |  4 ++--
 5 files changed, 25 insertions(+), 25 deletions(-)
 create mode 100644 src/open-api/utils/normalize-swagger-path.test.ts
 rename src/open-api/utils/{normalize-swagger-url.ts => normalize-swagger-path.ts} (74%)
 delete mode 100644 src/open-api/utils/normalize-swagger-url.test.ts

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 381d920..6519a21 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -1,7 +1,7 @@
 import { RequestHandler, HttpHandler, http } from 'msw'
 import type { OpenAPIV3, OpenAPIV2, OpenAPI } from 'openapi-types'
 import SwaggerParser from '@apidevtools/swagger-parser'
-import { normalizeSwaggerUrl } from './utils/normalize-swagger-url.js'
+import { normalizeSwaggerPath } from './utils/normalize-swagger-path.js'
 import { getServers } from './utils/get-servers.js'
 import { isAbsoluteUrl, joinPaths } from './utils/url.js'
 import { createResponseResolver } from './utils/open-api-utils.js'
@@ -12,7 +12,7 @@ const supportedHttpMethods = Object.keys(
 ) as unknown as SupportedHttpMethods
 
 export type MapOperationFunction = (args: {
-  url: string
+  path: string
   method: SupportedHttpMethods
   operation: OpenAPIV3.OperationObject
 }) => OpenAPIV3.OperationObject | undefined
@@ -37,7 +37,7 @@ export async function fromOpenApi(
 
   const pathItems = Object.entries(specification.paths ?? {})
   for (const item of pathItems) {
-    const [url, handlers] = item
+    const [path, handlers] = item
     const pathItem = handlers as
       | OpenAPIV2.PathItemObject
       | OpenAPIV3.PathItemObject
@@ -56,7 +56,7 @@ export async function fromOpenApi(
       }
 
       const operation = mapOperation
-        ? mapOperation({ url, method, operation: rowOperation })
+        ? mapOperation({ path, method, operation: rowOperation })
         : rowOperation
 
       if (!operation) {
@@ -66,10 +66,10 @@ export async function fromOpenApi(
       const serverUrls = getServers(specification)
 
       for (const baseUrl of serverUrls) {
-        const path = normalizeSwaggerUrl(url)
+        const normalizedPath = normalizeSwaggerPath(path)
         const requestUrl = isAbsoluteUrl(baseUrl)
-          ? new URL(path, baseUrl).href
-          : joinPaths(path, baseUrl)
+          ? new URL(normalizedPath, baseUrl).href
+          : joinPaths(normalizedPath, baseUrl)
 
         if (
           typeof operation.responses === 'undefined' ||
diff --git a/src/open-api/utils/normalize-swagger-path.test.ts b/src/open-api/utils/normalize-swagger-path.test.ts
new file mode 100644
index 0000000..9b2e061
--- /dev/null
+++ b/src/open-api/utils/normalize-swagger-path.test.ts
@@ -0,0 +1,15 @@
+import { normalizeSwaggerPath } from './normalize-swagger-path.js'
+
+it('replaces swagger path parameters with colons', () => {
+  expect(normalizeSwaggerPath('/user/{userId}')).toEqual('/user/:userId')
+  expect(
+    normalizeSwaggerPath('https://{subdomain}.example.com/{resource}/recent'),
+  ).toEqual('https://:subdomain.example.com/:resource/recent')
+})
+
+it('returns otherwise normal URL as-is', () => {
+  expect(normalizeSwaggerPath('/user/abc-123')).toEqual('/user/abc-123')
+  expect(
+    normalizeSwaggerPath('https://finance.example.com/reports/recent'),
+  ).toEqual('https://finance.example.com/reports/recent')
+})
diff --git a/src/open-api/utils/normalize-swagger-url.ts b/src/open-api/utils/normalize-swagger-path.ts
similarity index 74%
rename from src/open-api/utils/normalize-swagger-url.ts
rename to src/open-api/utils/normalize-swagger-path.ts
index b62a530..1bda65b 100644
--- a/src/open-api/utils/normalize-swagger-url.ts
+++ b/src/open-api/utils/normalize-swagger-path.ts
@@ -1,4 +1,4 @@
-export function normalizeSwaggerUrl(url: string): string {
+export function normalizeSwaggerPath(url: string): string {
   return (
     url
       // Replace OpenAPI style parameters (/pet/{petId})
diff --git a/src/open-api/utils/normalize-swagger-url.test.ts b/src/open-api/utils/normalize-swagger-url.test.ts
deleted file mode 100644
index 80b6910..0000000
--- a/src/open-api/utils/normalize-swagger-url.test.ts
+++ /dev/null
@@ -1,15 +0,0 @@
-import { normalizeSwaggerUrl } from './normalize-swagger-url.js'
-
-it('replaces swagger path parameters with colons', () => {
-  expect(normalizeSwaggerUrl('/user/{userId}')).toEqual('/user/:userId')
-  expect(
-    normalizeSwaggerUrl('https://{subdomain}.example.com/{resource}/recent'),
-  ).toEqual('https://:subdomain.example.com/:resource/recent')
-})
-
-it('returns otherwise normal URL as-is', () => {
-  expect(normalizeSwaggerUrl('/user/abc-123')).toEqual('/user/abc-123')
-  expect(
-    normalizeSwaggerUrl('https://finance.example.com/reports/recent'),
-  ).toEqual('https://finance.example.com/reports/recent')
-})
diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 8808017..4b04705 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -49,8 +49,8 @@ it('creates handlers based on provided filter', async () => {
     },
   })
 
-  const mapOperation: MapOperationFunction = ({ url, method, operation }) => {
-    return url === '/numbers' && method === 'get' ? operation : undefined
+  const mapOperation: MapOperationFunction = ({ path, method, operation }) => {
+    return path === '/numbers' && method === 'get' ? operation : undefined
   }
   const handlers = await fromOpenApi(openApiSpec, mapOperation)
 

From b73aa7b296ea27dff904b7181c079b1481b0ede0 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 15:12:15 +0200
Subject: [PATCH 07/15] refactor(fromOpenApi): rowOperation -> rawOperation

---
 src/open-api/from-open-api.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 6519a21..3e0e565 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -50,14 +50,14 @@ export async function fromOpenApi(
         continue
       }
 
-      const rowOperation = pathItem[method] as OpenAPIV3.OperationObject
-      if (!rowOperation) {
+      const rawOperation = pathItem[method] as OpenAPIV3.OperationObject
+      if (!rawOperation) {
         continue
       }
 
       const operation = mapOperation
-        ? mapOperation({ path, method, operation: rowOperation })
-        : rowOperation
+        ? mapOperation({ path, method, operation: rawOperation })
+        : rawOperation
 
       if (!operation) {
         continue

From e6a83f2df69a984ce840a9c24571720ce2f5c871 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 15:18:34 +0200
Subject: [PATCH 08/15] refactor(fromOpenApi): expose open api document to
 mapper function

---
 src/open-api/from-open-api.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 3e0e565..6647c79 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -15,6 +15,7 @@ export type MapOperationFunction = (args: {
   path: string
   method: SupportedHttpMethods
   operation: OpenAPIV3.OperationObject
+  document: OpenAPI.Document
 }) => OpenAPIV3.OperationObject | undefined
 
 /**
@@ -56,7 +57,12 @@ export async function fromOpenApi(
       }
 
       const operation = mapOperation
-        ? mapOperation({ path, method, operation: rawOperation })
+        ? mapOperation({
+            path,
+            method,
+            operation: rawOperation,
+            document: specification,
+          })
         : rawOperation
 
       if (!operation) {

From 89f2e80fc589ba5a59aff1b90fc3bdebd9b65203 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 15:20:07 +0200
Subject: [PATCH 09/15] test(fromOpenApi): inline mapper function

---
 test/oas/from-open-api.test.ts | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 4b04705..55694e8 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -1,8 +1,5 @@
 // @vitest-environment happy-dom
-import {
-  fromOpenApi,
-  MapOperationFunction,
-} from '../../src/open-api/from-open-api.js'
+import { fromOpenApi } from '../../src/open-api/from-open-api.js'
 import { createOpenApiSpec } from '../support/create-open-api-spec.js'
 import { InspectedHandler, inspectHandlers } from '../support/inspect.js'
 
@@ -49,10 +46,12 @@ it('creates handlers based on provided filter', async () => {
     },
   })
 
-  const mapOperation: MapOperationFunction = ({ path, method, operation }) => {
-    return path === '/numbers' && method === 'get' ? operation : undefined
-  }
-  const handlers = await fromOpenApi(openApiSpec, mapOperation)
+  const handlers = await fromOpenApi(
+    openApiSpec,
+    ({ path, method, operation }) => {
+      return path === '/numbers' && method === 'get' ? operation : undefined
+    },
+  )
 
   expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([
     {

From e3d239184d940c562768f737ab647c7aa682f9ce Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 15:32:11 +0200
Subject: [PATCH 10/15] test(fromOpenApi): expect one handler to be generated

---
 test/oas/from-open-api.test.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 55694e8..22c7a3a 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -53,7 +53,9 @@ it('creates handlers based on provided filter', async () => {
     },
   )
 
-  expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([
+  const inspectedHandlers = await inspectHandlers(handlers)
+  expect(inspectHandlers.length).toBe(1)
+  expect(inspectedHandlers).toEqual<InspectedHandler[]>([
     {
       handler: {
         method: 'GET',

From 45df8944b7508871660d9e84dfe7381eed3fbca8 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 15:51:32 +0200
Subject: [PATCH 11/15] test(fromOpenApi): add test for when mapper modifies
 operation

---
 test/oas/from-open-api.test.ts | 101 +++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 22c7a3a..9409178 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -70,3 +70,104 @@ it('creates handlers based on provided filter', async () => {
     },
   ])
 })
+
+it('creates handler with modified response', async () => {
+  const openApiSpec = createOpenApiSpec({
+    paths: {
+      '/numbers': {
+        description: 'Get numbers',
+        get: {
+          responses: {
+            200: {
+              content: {
+                'application/json': {
+                  example: [1, 2, 3],
+                },
+              },
+            },
+          },
+        },
+        put: {
+          responses: {
+            200: {
+              content: {
+                'application/json': {
+                  example: [1, 2, 3],
+                },
+              },
+            },
+          },
+        },
+      },
+      '/orders': {
+        get: {
+          responses: {
+            200: {
+              content: {
+                'application/json': {
+                  example: [{ id: 1 }, { id: 2 }, { id: 3 }],
+                },
+              },
+            },
+          },
+        },
+      },
+    },
+  })
+
+  const handlers = await fromOpenApi(
+    openApiSpec,
+    ({ path, method, operation }) => {
+      return path === '/numbers' && method === 'get'
+        ? {
+            ...operation,
+            responses: {
+              200: {
+                description: 'Get numbers response',
+                content: { 'application/json': { example: [10] } },
+              },
+            },
+          }
+        : operation
+    },
+  )
+
+  expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([
+    {
+      handler: {
+        method: 'GET',
+        path: 'http://localhost/numbers',
+      },
+      response: {
+        status: 200,
+        statusText: 'OK',
+        headers: expect.arrayContaining([['content-type', 'application/json']]),
+        body: JSON.stringify([10]),
+      },
+    },
+    {
+      handler: {
+        method: 'PUT',
+        path: 'http://localhost/numbers',
+      },
+      response: {
+        status: 200,
+        statusText: 'OK',
+        headers: expect.arrayContaining([['content-type', 'application/json']]),
+        body: JSON.stringify([1, 2, 3]),
+      },
+    },
+    {
+      handler: {
+        method: 'GET',
+        path: 'http://localhost/orders',
+      },
+      response: {
+        status: 200,
+        statusText: 'OK',
+        headers: expect.arrayContaining([['content-type', 'application/json']]),
+        body: JSON.stringify([{ id: 1 }, { id: 2 }, { id: 3 }]),
+      },
+    },
+  ])
+})

From ef583e73a68e6ebbfffb2a91396ec7014dd03b13 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Wed, 17 Jul 2024 16:03:49 +0200
Subject: [PATCH 12/15] feat(fromOpenApi): rename parameter from url to path

---
 src/open-api/utils/normalize-swagger-path.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/open-api/utils/normalize-swagger-path.ts b/src/open-api/utils/normalize-swagger-path.ts
index 1bda65b..29cf021 100644
--- a/src/open-api/utils/normalize-swagger-path.ts
+++ b/src/open-api/utils/normalize-swagger-path.ts
@@ -1,6 +1,6 @@
-export function normalizeSwaggerPath(url: string): string {
+export function normalizeSwaggerPath(path: string): string {
   return (
-    url
+    path
       // Replace OpenAPI style parameters (/pet/{petId})
       // with the common path parameters (/pet/:petId).
       .replace(/\{(.+?)\}/g, ':$1')

From 898c44385b7694356ea113dd2d7b6f37f15dc066 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Thu, 18 Jul 2024 11:46:08 +0200
Subject: [PATCH 13/15] feat(fromOpenApi): improve typings

---
 src/open-api/from-open-api.ts                | 19 +++++++++++++------
 src/open-api/utils/normalize-swagger-path.ts |  2 +-
 test/oas/from-open-api.test.ts               |  6 ++++++
 test/oas/oas-json-schema.test.ts             |  9 ++++++---
 test/oas/oas-response-headers.test.ts        |  1 +
 test/oas/oas-servers.test.ts                 |  4 ++++
 test/support/create-open-api-spec.ts         | 10 +++++-----
 7 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 6647c79..8117cc8 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -11,8 +11,10 @@ const supportedHttpMethods = Object.keys(
   http,
 ) as unknown as SupportedHttpMethods
 
-export type MapOperationFunction = (args: {
-  path: string
+type ExtractPaths<T> = T extends { paths: infer P } ? keyof P : never
+
+export type MapOperationFunction<TPaths extends string> = (args: {
+  path: TPaths
   method: SupportedHttpMethods
   operation: OpenAPIV3.OperationObject
   document: OpenAPI.Document
@@ -25,9 +27,14 @@ export type MapOperationFunction = (args: {
  * import specification from './api.oas.json'
  * await fromOpenApi(specification)
  */
-export async function fromOpenApi(
-  document: string | OpenAPI.Document | OpenAPIV3.Document | OpenAPIV2.Document,
-  mapOperation?: MapOperationFunction,
+
+export async function fromOpenApi<
+  T extends string | OpenAPI.Document | OpenAPIV2.Document | OpenAPIV3.Document,
+>(
+  document: T,
+  mapOperation?: MapOperationFunction<
+    T extends string ? string : ExtractPaths<T>
+  >,
 ): Promise<Array<RequestHandler>> {
   const specification = await SwaggerParser.dereference(document)
   const requestHandlers: Array<RequestHandler> = []
@@ -38,7 +45,7 @@ export async function fromOpenApi(
 
   const pathItems = Object.entries(specification.paths ?? {})
   for (const item of pathItems) {
-    const [path, handlers] = item
+    const [path, handlers] = item as [ExtractPaths<T>, any]
     const pathItem = handlers as
       | OpenAPIV2.PathItemObject
       | OpenAPIV3.PathItemObject
diff --git a/src/open-api/utils/normalize-swagger-path.ts b/src/open-api/utils/normalize-swagger-path.ts
index 29cf021..96a8227 100644
--- a/src/open-api/utils/normalize-swagger-path.ts
+++ b/src/open-api/utils/normalize-swagger-path.ts
@@ -1,4 +1,4 @@
-export function normalizeSwaggerPath(path: string): string {
+export function normalizeSwaggerPath<T extends string>(path: T) {
   return (
     path
       // Replace OpenAPI style parameters (/pet/{petId})
diff --git a/test/oas/from-open-api.test.ts b/test/oas/from-open-api.test.ts
index 9409178..d9cd0d1 100644
--- a/test/oas/from-open-api.test.ts
+++ b/test/oas/from-open-api.test.ts
@@ -10,6 +10,7 @@ it('creates handlers based on provided filter', async () => {
         get: {
           responses: {
             200: {
+              description: 'Numbers response',
               content: {
                 'application/json': {
                   example: [1, 2, 3],
@@ -21,6 +22,7 @@ it('creates handlers based on provided filter', async () => {
         put: {
           responses: {
             200: {
+              description: 'Numbers response',
               content: {
                 'application/json': {
                   example: [1, 2, 3],
@@ -34,6 +36,7 @@ it('creates handlers based on provided filter', async () => {
         get: {
           responses: {
             200: {
+              description: 'Orders response',
               content: {
                 'application/json': {
                   example: [{ id: 1 }, { id: 2 }, { id: 3 }],
@@ -79,6 +82,7 @@ it('creates handler with modified response', async () => {
         get: {
           responses: {
             200: {
+              description: 'Numbers response',
               content: {
                 'application/json': {
                   example: [1, 2, 3],
@@ -90,6 +94,7 @@ it('creates handler with modified response', async () => {
         put: {
           responses: {
             200: {
+              description: 'Numbers response',
               content: {
                 'application/json': {
                   example: [1, 2, 3],
@@ -103,6 +108,7 @@ it('creates handler with modified response', async () => {
         get: {
           responses: {
             200: {
+              description: 'Orders response',
               content: {
                 'application/json': {
                   example: [{ id: 1 }, { id: 2 }, { id: 3 }],
diff --git a/test/oas/oas-json-schema.test.ts b/test/oas/oas-json-schema.test.ts
index 83d818e..3d7ac92 100644
--- a/test/oas/oas-json-schema.test.ts
+++ b/test/oas/oas-json-schema.test.ts
@@ -3,6 +3,7 @@ import { fromOpenApi } from '../../src/open-api/from-open-api.js'
 import { withHandlers } from '../support/with-handlers.js'
 import { createOpenApiSpec } from '../support/create-open-api-spec.js'
 import { InspectedHandler, inspectHandlers } from '../support/inspect.js'
+import { OpenAPI } from 'openapi-types'
 
 const ID_REGEXP =
   /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/
@@ -15,6 +16,7 @@ it('supports JSON Schema object', async () => {
           get: {
             responses: {
               '200': {
+                description: 'Cart response',
                 content: {
                   'application/json': {
                     schema: {
@@ -79,10 +81,10 @@ it('normalizes path parameters', async () => {
     createOpenApiSpec({
       paths: {
         '/pet/{petId}': {
-          get: { responses: { 200: {} } },
+          get: { responses: { 200: { description: '' } } },
         },
         '/pet/{petId}/{foodId}': {
-          get: { responses: { 200: {} } },
+          get: { responses: { 200: { description: '' } } },
         },
       },
     }),
@@ -114,7 +116,7 @@ it('treats operations without "responses" as not implemented (501)', async () =>
           get: { responses: null },
         },
       },
-    }),
+    } as unknown as OpenAPI.Document),
   )
   expect(await inspectHandlers(handlers)).toEqual<InspectedHandler[]>([
     {
@@ -203,6 +205,7 @@ it('respects the "Accept" request header', async () => {
           get: {
             responses: {
               200: {
+                description: 'User response',
                 content: {
                   'application/json': {
                     example: { id: 'user-1' },
diff --git a/test/oas/oas-response-headers.test.ts b/test/oas/oas-response-headers.test.ts
index 1acac38..63ed649 100644
--- a/test/oas/oas-response-headers.test.ts
+++ b/test/oas/oas-response-headers.test.ts
@@ -11,6 +11,7 @@ it('supports response headers', async () => {
           get: {
             responses: {
               200: {
+                description: 'User response',
                 headers: {
                   'X-Rate-Limit-Remaining': {
                     schema: {
diff --git a/test/oas/oas-servers.test.ts b/test/oas/oas-servers.test.ts
index 5651d9b..d799684 100644
--- a/test/oas/oas-servers.test.ts
+++ b/test/oas/oas-servers.test.ts
@@ -12,6 +12,7 @@ it('supports absolute server url', async () => {
           get: {
             responses: {
               200: {
+                description: 'Numbers response',
                 content: {
                   'application/json': {
                     example: [1, 2, 3],
@@ -50,6 +51,7 @@ it('supports relative server url', async () => {
           post: {
             responses: {
               200: {
+                description: 'Token response',
                 content: {
                   'plain/text': {
                     example: 'abc-123',
@@ -87,6 +89,7 @@ it('supports multiple server urls', async () => {
           get: {
             responses: {
               200: {
+                description: 'Numbers response',
                 content: {
                   'application/json': {
                     example: [1, 2, 3],
@@ -136,6 +139,7 @@ it('supports the "basePath" url', async () => {
           get: {
             responses: {
               200: {
+                description: 'Strings response',
                 content: {
                   'application/json': {
                     example: ['a', 'b', 'c'],
diff --git a/test/support/create-open-api-spec.ts b/test/support/create-open-api-spec.ts
index 2b61427..45e33f1 100644
--- a/test/support/create-open-api-spec.ts
+++ b/test/support/create-open-api-spec.ts
@@ -1,10 +1,10 @@
 import { OpenAPI } from 'openapi-types'
 
-export function createOpenApiSpec(
-  document: Partial<OpenAPI.Document>,
-): OpenAPI.Document {
+export function createOpenApiSpec<T extends Partial<OpenAPI.Document>>(
+  document: T,
+) {
   return Object.assign(
-    {} as OpenAPI.Document,
+    {},
     {
       openapi: '3.0.0',
       info: {
@@ -14,5 +14,5 @@ export function createOpenApiSpec(
       paths: {},
     },
     document,
-  )
+  ) satisfies T
 }

From a214ae2cc4805fa67a223e3dcae2d7426cba0ec4 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Thu, 18 Jul 2024 11:52:07 +0200
Subject: [PATCH 14/15] refactor(fromOpenApi): make generic singular

---
 src/open-api/from-open-api.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 8117cc8..9c67583 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -13,8 +13,8 @@ const supportedHttpMethods = Object.keys(
 
 type ExtractPaths<T> = T extends { paths: infer P } ? keyof P : never
 
-export type MapOperationFunction<TPaths extends string> = (args: {
-  path: TPaths
+export type MapOperationFunction<TPath extends string> = (args: {
+  path: TPath
   method: SupportedHttpMethods
   operation: OpenAPIV3.OperationObject
   document: OpenAPI.Document

From 053d58b8e41c8bd943d63745b6b50d4debdad5f0 Mon Sep 17 00:00:00 2001
From: Jaunius Eitmantis <jaunius.eitmantis@mentimeter.com>
Date: Thu, 18 Jul 2024 12:00:29 +0200
Subject: [PATCH 15/15] refactor(fromOpenApi): extract common type to a
 separate

---
 src/open-api/from-open-api.ts | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/open-api/from-open-api.ts b/src/open-api/from-open-api.ts
index 9c67583..05172ea 100644
--- a/src/open-api/from-open-api.ts
+++ b/src/open-api/from-open-api.ts
@@ -11,13 +11,19 @@ const supportedHttpMethods = Object.keys(
   http,
 ) as unknown as SupportedHttpMethods
 
+type OpenApiDocument =
+  | string
+  | OpenAPI.Document
+  | OpenAPIV2.Document
+  | OpenAPIV3.Document
+
 type ExtractPaths<T> = T extends { paths: infer P } ? keyof P : never
 
 export type MapOperationFunction<TPath extends string> = (args: {
   path: TPath
   method: SupportedHttpMethods
   operation: OpenAPIV3.OperationObject
-  document: OpenAPI.Document
+  document: OpenApiDocument
 }) => OpenAPIV3.OperationObject | undefined
 
 /**
@@ -28,9 +34,7 @@ export type MapOperationFunction<TPath extends string> = (args: {
  * await fromOpenApi(specification)
  */
 
-export async function fromOpenApi<
-  T extends string | OpenAPI.Document | OpenAPIV2.Document | OpenAPIV3.Document,
->(
+export async function fromOpenApi<T extends OpenApiDocument>(
   document: T,
   mapOperation?: MapOperationFunction<
     T extends string ? string : ExtractPaths<T>