feat: support runtime delay functions (#1281)

* feat: support runtime delay functions

* ci: add regression test for runtime delay functions

* refactor: rename delayCalcRuntime to delayMockFunction and improve docs

* refactor: rename delayMockFunction to delayFunctionLazyExecute

Author: huwshimi

docs/src/pages/reference/configuration/output.md

@@ -300,6 +300,13 @@ Default Value: `1000`.
 
 Use to specify the delay time for the mock. It can either be a fixed number or a function that returns a number.
 
+#### delayFunctionLazyExecute
+
+Type: `boolean`.
+
+Gives you the possibility to have functions that are passed to `delay` to be
+executed at runtime rather than when the mocks are generated.
+
 #### useExamples
 
 Type: `Boolean`.
@@ -1010,6 +1017,13 @@ module.exports = {
 };
 ```
 
+#### delayFunctionLazyExecute
+
+Type: `boolean`.
+
+Gives you the possibility to have functions that are passed to `delay` to be
+executed at runtime rather than when the mocks are generated.
+
 ##### arrayMin
 
 Type: `Number`.

packages/core/src/types.ts

@@ -230,6 +230,9 @@ export type GlobalMockOptions = {
   useExamples?: boolean;
   // This is used to set the delay to your own custom value
   delay?: number | (() => number);
+  // This is used to execute functions that are passed to the 'delay' argument
+  // at runtime rather than build time.
+  delayFunctionLazyExecute?: boolean;
   // This is used to set the base url to your own custom value
   baseUrl?: string;
   // This is used to set the locale of the faker library

packages/mock/src/delay.ts

@@ -3,14 +3,17 @@ import { GlobalMockOptions, NormalizedOverrideOutput } from '@orval/core';
 export const getDelay = (
   override?: NormalizedOverrideOutput,
   options?: GlobalMockOptions,
-): number => {
+): GlobalMockOptions['delay'] => {
   const overrideDelay =
     typeof override?.mock?.delay === 'number'
       ? override?.mock?.delay
       : options?.delay;
+  const delayFunctionLazyExecute =
+    override?.mock?.delayFunctionLazyExecute ??
+    options?.delayFunctionLazyExecute;
   switch (typeof overrideDelay) {
     case 'function':
-      return overrideDelay();
+      return delayFunctionLazyExecute ? overrideDelay : overrideDelay();
     case 'number':
       return overrideDelay;
     default:

packages/mock/src/msw/index.ts

@@ -84,10 +84,11 @@ export const generateMSW = (
     ? `export const ${getResponseMockFunctionName} = (${isResponseOverridable ? `overrideResponse: any = {}` : ''})${mockData ? '' : `: ${returnType}`} => (${value})\n\n`
     : '';
 
+  const delayTime = getDelay(override, !isFunction(mock) ? mock : undefined);
   const handlerImplementation = `
 export const ${handlerName} = (${isReturnHttpResponse && !isTextPlain ? `overrideResponse?: ${returnType}` : ''}) => {
   return http.${verb}('${route}', async () => {
-    await delay(${getDelay(override, !isFunction(mock) ? mock : undefined)});
+    await delay(${isFunction(delayTime) ? `(${delayTime})()` : delayTime});
     return new HttpResponse(${
       isReturnHttpResponse
         ? isTextPlain

tests/configs/default.config.ts

@@ -122,4 +122,16 @@ export default defineConfig({
       },
     },
   },
+  'runtime-mock-delay': {
+    input: '../specifications/petstore.yaml',
+    output: {
+      mock: {
+        delay: () => 400,
+        delayFunctionLazyExecute: true,
+        type: 'msw',
+      },
+      schemas: '../generated/default/runtime-mock-delay/model',
+      target: '../generated/default/runtime-mock-delay/endpoints.ts',
+    },
+  },
 });