Make all conditions async

docs/Routing.md

@@ -767,7 +767,7 @@ run every time a new request arrives, and which need to return `true` for the ro
 
 ```js
 // A condition that randomly allows a route to match
-router.addCondition('random', (ctx, num) => {
+router.addCondition('random', async (ctx, num) => {
   // Winner
   if (Math.floor(Math.random() * 10) === num) return true;
 
@@ -779,7 +779,7 @@ router.addCondition('random', (ctx, num) => {
 router.get('/maybe').requires('random', 5).to('foo#bar');
 ```
 
-Use whatever request information you need. Conditions can be `async` functions too.
+As `async` functions, conditions can access a wide range of information.
 
 ```js
 // A condition to check query parameters (useful for mock web services)

src/plugins/default-conditions.ts

@@ -10,7 +10,7 @@ export default function defaultConditionsPlugin(app: App): void {
   router.addCondition('host', hostCondition);
 }
 
-function headerCondition(ctx: MojoContext, requirement: Record<string, RegExp>): boolean {
+async function headerCondition(ctx: MojoContext, requirement: Record<string, RegExp>): Promise<boolean> {
   for (const [name, regex] of Object.entries(requirement)) {
     const value = ctx.req.get(name);
     if (typeof value !== 'string') return false;
@@ -20,6 +20,6 @@ function headerCondition(ctx: MojoContext, requirement: Record<string, RegExp>):
   return true;
 }
 
-function hostCondition(ctx: MojoContext, requirement: RegExp): boolean {
+async function hostCondition(ctx: MojoContext, requirement: RegExp): Promise<boolean> {
   return headerCondition(ctx, {Host: requirement});
 }

src/router.ts

@@ -13,7 +13,7 @@ interface RouteSpec {
   websocket: boolean;
 }
 
-type RouteCondition = (ctx: MojoContext, requirements: any) => boolean;
+type RouteCondition = (ctx: MojoContext, requirements: any) => Promise<boolean>;
 
 const PLACEHOLDER = {};