docs: Remove unnecessary promises (#915)

www/docs/configuration/callbacks.md

@@ -17,16 +17,16 @@ You can specify a handler for any of the callbacks below.
 ...
   callbacks: {
     signIn: async (user, account, profile) => {
-      return Promise.resolve(true)
+      return true
     },
     redirect: async (url, baseUrl) => {
-      return Promise.resolve(baseUrl)
+      return baseUrl
     },
     session: async (session, user) => {
-      return Promise.resolve(session)
+      return session
     },
     jwt: async (token, user, account, profile, isNewUser) => {
-      return Promise.resolve(token)
+      return token
     }
 ...
 }
@@ -50,13 +50,13 @@ callbacks: {
   signIn: async (user, account, profile) => {
     const isAllowedToSignIn = true
     if (isAllowedToSignIn) {
-      return Promise.resolve(true)
+      return true
     } else {
       // Return false to display a default error message
-      return Promise.resolve(false)
+      return false
       // You can also Reject this callback with an Error or with a URL:
-      // return Promise.reject(new Error('error message')) // Redirect to error page
-      // return Promise.reject('/path/to/redirect')        // Redirect to a URL
+      // throw new Error('error message') // Redirect to error page
+      // return '/path/to/redirect'        // Redirect to a URL
     }
   }
 }
@@ -97,8 +97,8 @@ callbacks: {
    */
   redirect: async (url, baseUrl) => {
     return url.startsWith(baseUrl)
-      ? Promise.resolve(url)
-      : Promise.resolve(baseUrl)
+      ? url
+      : baseUrl
   }
 }
 ```
@@ -127,7 +127,7 @@ callbacks: {
    */
   session: async (session, user) => {
     session.foo = 'bar' // Add property to session
-    return Promise.resolve(session)
+    return session
   }
 }
 ```
@@ -171,7 +171,7 @@ callbacks: {
     const isSignIn = (user) ? true : false
     // Add auth_time to token on signin in
     if (isSignIn) { token.auth_time = Math.floor(Date.now() / 1000) }
-    return Promise.resolve(token)
+    return token
   }
 }
 ```

www/docs/configuration/options.md

@@ -231,16 +231,16 @@ You can specify a handler for any of the callbacks below.
 ```js
 callbacks: {
   signIn: async (user, account, profile) => {
-    return Promise.resolve(true)
+    return true
   },
   redirect: async (url, baseUrl) => {
-    return Promise.resolve(baseUrl)
+    return baseUrl
   },
   session: async (session, user) => {
-    return Promise.resolve(session)
+    return session
   },
   jwt: async (token, user, account, profile, isNewUser) => {
-    return Promise.resolve(token)
+    return token
   }
 }
 ```

www/docs/configuration/providers.md

@@ -208,9 +208,9 @@ providers: [
       }
       if (user) {
         // Any user object returned here will be saved in the JSON Web Token
-        return Promise.resolve(user)
+        return user
       } else {
-        return Promise.resolve(null)
+        return null
       }
     }
   })

www/docs/providers/credentials.md

@@ -27,9 +27,9 @@ The Credentials provider is specified like other providers, except that you need
 
   If you return `false` or `null` then an error will be displayed advising the user to check their details.
 
-3. `Promise.Rejected()` with an Error or a URL.
+3. You can throw an Error or a URL (a string).
 
-  If you reject the promise with an Error, the user will be sent to the error page with the error message as a query parameter. If you reject the promise with a URL (a string), the user will be redirected to the URL.
+  If you throw an Error, the user will be sent to the error page with the error message as a query parameter. If throw a URL (a string), the user will be redirected to the URL.
 
 ```js title="pages/api/auth/[...nextauth].js"
 import Providers from `next-auth/providers`
@@ -51,13 +51,13 @@ providers: [
 
       if (user) {
         // Any object returned will be saved in `user` property of the JWT
-        return Promise.resolve(user)
+        return user
       } else {
         // If you return null or false then the credentials will be rejected
-        return Promise.resolve(null)
+        return null
         // You can also Reject this callback with an Error or with a URL:
-        // return Promise.reject(new Error('error message')) // Redirect to error page
-        // return Promise.reject('/path/to/redirect')        // Redirect to a URL
+        // throw new Error('error message') // Redirect to error page
+        // throw '/path/to/redirect'        // Redirect to a URL
       }
     }
   })
@@ -84,7 +84,7 @@ As with all providers, the order you specify them is the order they are displaye
       name: "Domain Account",
       authorize: async (credentials) => {
         const user = { /* add function to get user */ }
-        return Promise.resolve(user)
+        return user
       },
       credentials: {
         domain: { label: "Domain", type: "text ", placeholder: "CORPNET", value: "CORPNET" },
@@ -97,7 +97,7 @@ As with all providers, the order you specify them is the order they are displaye
       name: "Two Factor Auth",
       authorize: async (credentials) => {
         const user = { /* add function to get user */ } 
-        return Promise.resolve(user)
+        return user
       },
       credentials: {
         email: { label: "Username", type: "text ", placeholder: "jsmith" },

www/docs/providers/google.md

@@ -63,9 +63,9 @@ const options = {
       if (account.provider === 'google' &&
           profile.verified_email === true &&
           profile.email.endsWith('@example.com')) {
-        return Promise.resolve(true)
+        return true
       } else {
-        return Promise.resolve(false)
+        return false
       }
     },
   }

www/docs/tutorials/creating-a-database-adapter.md

@@ -149,7 +149,7 @@ const Adapter = (config, options = {}) => {
       return null
     }
 
-    return Promise.resolve({
+    return {
       createUser,
       getUser,
       getUserByEmail,
@@ -166,7 +166,7 @@ const Adapter = (config, options = {}) => {
       createVerificationRequest,
       getVerificationRequest,
       deleteVerificationRequest
-    })
+    }
   }
 
   return {