feat(useFetch): allow configure lifecycle handler behavior

packages/core/useFetch/index.md

@@ -166,6 +166,46 @@ const useMyFetch = createFetch({
 const { isFetching, error, data } = useMyFetch('users')
 ```
 
+If you want to control the behavior of `beforeFetch`, `afterFetch`, `onFetchError` between the pre-configured instance and newly spawned instance. You can provide a `combination` option to toggle between `overwrite` or `chaining`.
+
+```ts
+const useMyFetch = createFetch({
+  baseUrl: 'https://my-api.com',
+  combination: 'overwrite',
+  options: {
+    // beforeFetch in pre-configured instance will only run when the newly spawned instance do not pass beforeFetch
+    async beforeFetch({ options }) {
+      const myToken = await getMyToken()
+      options.headers.Authorization = `Bearer ${myToken}`
+
+      return { options }
+    },
+  },
+})
+
+// use useMyFetch beforeFetch
+const { isFetching, error, data } = useMyFetch('users')
+
+// use custom beforeFetch
+const { isFetching, error, data } = useMyFetch('users', {
+  async beforeFetch({ url, options, cancel }) {
+    const myToken = await getMyToken()
+
+    if (!myToken)
+      cancel()
+
+    options.headers = {
+      ...options.headers,
+      Authorization: `Bearer ${myToken}`,
+    }
+
+    return {
+      options,
+    }
+  },
+})
+```
+
 ### Events
 
 The `onFetchResponse` and `onFetchError` will fire on fetch request responses and errors respectively.

packages/core/useFetch/index.test.ts

@@ -1,8 +1,8 @@
-import { ref } from 'vue-demi'
 import { until } from '@vueuse/shared'
+import { ref } from 'vue-demi'
 import { retry } from '../../.test'
-import '../../.test/mockServer'
 import { createFetch, useFetch } from '.'
+import '../../.test/mockServer'
 
 const jsonMessage = { hello: 'world' }
 const jsonUrl = `https://example.com?json=${encodeURI(JSON.stringify(jsonMessage))}`
@@ -286,6 +286,157 @@ describe('useFetch', () => {
     })
   })
 
+  test('should overwrite beforeFetch function when using a factory instance', async () => {
+    const useMyFetch = createFetch({
+      baseUrl: 'https://example.com',
+      combination: 'overwrite',
+      options: {
+        beforeFetch({ options }) {
+          options.headers = { ...options.headers, Global: 'foo' }
+          return { options }
+        },
+      },
+    })
+    useMyFetch('test', {
+      beforeFetch({ options }) {
+        options.headers = { ...options.headers, Local: 'foo' }
+        return { options }
+      },
+    })
+
+    await retry(() => {
+      expect(fetchSpyHeaders()).toMatchObject({ Local: 'foo' })
+    })
+  })
+
+  test('should overwrite afterFetch function when using a factory instance', async () => {
+    const useMyFetch = createFetch({
+      baseUrl: 'https://example.com',
+      combination: 'overwrite',
+      options: {
+        afterFetch(ctx) {
+          ctx.data.global = 'Global'
+          return ctx
+        },
+      },
+    })
+    const { data } = useMyFetch('test?json', {
+      afterFetch(ctx) {
+        ctx.data.local = 'Local'
+        return ctx
+      },
+    }).json()
+
+    await retry(() => {
+      expect(data.value).toEqual(expect.objectContaining({ local: 'Local' }))
+      expect(data.value).toEqual(expect.not.objectContaining({ global: 'Global' }))
+    })
+  })
+
+  test('should overwrite onFetchError function when using a factory instance', async () => {
+    const useMyFetch = createFetch({
+      baseUrl: 'https://example.com',
+      combination: 'overwrite',
+      options: {
+        onFetchError(ctx) {
+          ctx.data.global = 'Global'
+          return ctx
+        },
+      },
+    })
+    const { data } = useMyFetch('test?status=400&json', {
+      onFetchError(ctx) {
+        ctx.data.local = 'Local'
+        return ctx
+      },
+    }).json()
+
+    await retry(() => {
+      expect(data.value).toEqual(expect.objectContaining({ local: 'Local' }))
+      expect(data.value).toEqual(expect.not.objectContaining({ global: 'Global' }))
+    })
+  })
+
+  test('should overwrite beforeFetch function when using a factory instance and the options object in useMyFetch', async () => {
+    const useMyFetch = createFetch({
+      baseUrl: 'https://example.com',
+      combination: 'overwrite',
+      options: {
+        beforeFetch({ options }) {
+          options.headers = { ...options.headers, Global: 'foo' }
+          return { options }
+        },
+      },
+    })
+    useMyFetch(
+      'test',
+      { method: 'GET' },
+      {
+        beforeFetch({ options }) {
+          options.headers = { ...options.headers, Local: 'foo' }
+          return { options }
+        },
+      })
+
+    await retry(() => {
+      expect(fetchSpyHeaders()).toMatchObject({ Local: 'foo' })
+    })
+  })
+
+  test('should overwrite afterFetch function when using a factory instance and the options object in useMyFetch', async () => {
+    const useMyFetch = createFetch({
+      baseUrl: 'https://example.com',
+      combination: 'overwrite',
+      options: {
+        afterFetch(ctx) {
+          ctx.data.global = 'Global'
+          return ctx
+        },
+      },
+    })
+    const { data } = useMyFetch(
+      'test?json',
+      { method: 'GET' },
+      {
+        afterFetch(ctx) {
+          ctx.data.local = 'Local'
+          return ctx
+        },
+      }).json()
+
+    await retry(() => {
+      expect(data.value).toEqual(expect.objectContaining({ local: 'Local' }))
+      expect(data.value).toEqual(expect.not.objectContaining({ global: 'Global' }))
+    })
+  })
+
+  test('should overwrite onFetchError function when using a factory instance and the options object in useMyFetch', async () => {
+    const useMyFetch = createFetch({
+      baseUrl: 'https://example.com',
+      combination: 'overwrite',
+      options: {
+        onFetchError(ctx) {
+          ctx.data.global = 'Global'
+          return ctx
+        },
+      },
+    })
+    const { data } = useMyFetch(
+      'test?status=400&json',
+      { method: 'GET' },
+      {
+        onFetchError(ctx) {
+          ctx.data.local = 'Local'
+          return ctx
+        },
+      }).json()
+
+    await retry(() => {
+      expect(data.value).toEqual(expect.objectContaining({ local: 'Local' }))
+      expect(data.value).toEqual(expect.not.objectContaining({ global: 'Global' }))
+    })
+  })
+
   test('should run the beforeFetch function and add headers to the request', async () => {
     useFetch('https://example.com', { headers: { 'Accept-Language': 'en-US' } }, {
       beforeFetch({ options }) {

packages/core/useFetch/index.ts

@@ -1,6 +1,6 @@
-import type { ComputedRef, Ref } from 'vue-demi'
 import type { EventHookOn, Fn, MaybeComputedRef, Stoppable } from '@vueuse/shared'
 import { containsProp, createEventHook, resolveRef, resolveUnref, until, useTimeoutFn } from '@vueuse/shared'
+import type { ComputedRef, Ref } from 'vue-demi'
 import { computed, isRef, ref, shallowRef, watch } from 'vue-demi'
 import { defaultWindow } from '../_configurable'
 
@@ -90,6 +90,7 @@ export interface UseFetchReturn<T> {
 
 type DataType = 'text' | 'json' | 'blob' | 'arrayBuffer' | 'formData'
 type HttpMethod = 'GET' | 'POST' | 'PUT' | 'DELETE' | 'PATCH' | 'HEAD' | 'OPTIONS'
+type Combination = 'overwrite' | 'chain'
 
 const payloadMapping: Record<string, string> = {
   json: 'application/json',
@@ -187,6 +188,12 @@ export interface CreateFetchOptions {
    */
   baseUrl?: MaybeComputedRef<string>
 
+  /**
+   * Determine the inherit behavior for beforeFetch, afterFetch, onFetchError
+   * @default 'chain'
+   */
+  combination?: Combination
+
   /**
    * Default Options for the useFetch function
    */
@@ -214,17 +221,30 @@ function headersToObject(headers: HeadersInit | undefined) {
   return headers
 }
 
-function chainCallbacks<T = any>(...callbacks: (((ctx: T) => void | Partial<T> | Promise<void | Partial<T>>) | undefined)[]) {
-  return async (ctx: T) => {
-    await callbacks.reduce((prevCallback, callback) => prevCallback.then(async () => {
-      if (callback)
-        ctx = { ...ctx, ...(await callback(ctx)) }
-    }), Promise.resolve())
-    return ctx
+function combineCallbacks<T = any>(combination: Combination, ...callbacks: (((ctx: T) => void | Partial<T> | Promise<void | Partial<T>>) | undefined)[]) {
+  if (combination === 'overwrite') {
+    // use last callback
+    return async (ctx: T) => {
+      const callback = callbacks[callbacks.length - 1]
+      if (callback !== undefined)
+        await callback(ctx)
+      return ctx
+    }
+  }
+  else {
+    // chaining and combine result
+    return async (ctx: T) => {
+      await callbacks.reduce((prevCallback, callback) => prevCallback.then(async () => {
+        if (callback)
+          ctx = { ...ctx, ...(await callback(ctx)) }
+      }), Promise.resolve())
+      return ctx
+    }
   }
 }
 
 export function createFetch(config: CreateFetchOptions = {}) {
+  const _combination = config.combination || 'chain' as Combination
   const _options = config.options || {}
   const _fetchOptions = config.fetchOptions || {}
 
@@ -243,9 +263,9 @@ export function createFetch(config: CreateFetchOptions = {}) {
         options = {
           ...options,
           ...args[0],
-          beforeFetch: chainCallbacks(_options.beforeFetch, args[0].beforeFetch),
-          afterFetch: chainCallbacks(_options.afterFetch, args[0].afterFetch),
-          onFetchError: chainCallbacks(_options.onFetchError, args[0].onFetchError),
+          beforeFetch: combineCallbacks(_combination, _options.beforeFetch, args[0].beforeFetch),
+          afterFetch: combineCallbacks(_combination, _options.afterFetch, args[0].afterFetch),
+          onFetchError: combineCallbacks(_combination, _options.onFetchError, args[0].onFetchError),
         }
       }
       else {
@@ -264,9 +284,9 @@ export function createFetch(config: CreateFetchOptions = {}) {
       options = {
         ...options,
         ...args[1],
-        beforeFetch: chainCallbacks(_options.beforeFetch, args[1].beforeFetch),
-        afterFetch: chainCallbacks(_options.afterFetch, args[1].afterFetch),
-        onFetchError: chainCallbacks(_options.onFetchError, args[1].onFetchError),
+        beforeFetch: combineCallbacks(_combination, _options.beforeFetch, args[1].beforeFetch),
+        afterFetch: combineCallbacks(_combination, _options.afterFetch, args[1].afterFetch),
+        onFetchError: combineCallbacks(_combination, _options.onFetchError, args[1].onFetchError),
       }
     }