feat: add clear()

README.md

@@ -63,8 +63,9 @@ async function someOtherFunc(
 ```
 
 - `createContext(context)`: Create a new async context object. The input can be an object (sync) or a `Promise` returning function (async).
-- `Context.merge(context)`: Merge new context input to create a new async context object.
 - `Context.set(context)`: Set context to a new value. This is used when `createContext()` is made by the producer while `set()` is called by consumer.
+- `Context.merge(context)`: Merge new context input to create a new async context object.
+- `Context.clear()`: Clear the context as if the context is created with no context argument during creation or with `set()` method calls. Used mostly for testing.
 
 [circleci-image]: https://circleci.com/gh/unional/async-fp/tree/master.svg?style=shield
 [circleci-url]: https://circleci.com/gh/unional/async-fp/tree/master

src/createContext.spec.ts

@@ -55,3 +55,14 @@ test('get() rejects if context does not exist', async () => {
     name: 'ContextNotSet'
   })
 })
+
+test('clear() reverts context to unset state. This is used for testing', async () => {
+  const ctx = createContext({})
+
+  ctx.clear()
+
+  const err = a.throws(() => ctx.get(), IsoError)
+  a.satisfies(err, {
+    name: 'ContextNotSet'
+  })
+})

src/createContext.ts

@@ -3,6 +3,7 @@ import { ContextNotSet } from './errors'
 export type Context<T> = {
   get(): Promise<T>,
   set(context: T | (() => Promise<T>)): void
+  clear(): void
   merge<R>(context: R | (() => Promise<R>)): Context<T & R>
 }
 
@@ -20,6 +21,9 @@ export function createContext<T extends Record<string | symbol, any>>(context?:
     set(context: (() => Promise<T>) | T) {
       ready = typeof context === 'function' ? (context as any)() : Promise.resolve(context)
     },
+    clear() {
+      ready = undefined
+    },
     merge(context) {
       return createContext(async () => {
         const r = typeof context === 'function' ? await (context as any)() : context