Error response enhancements, CoreID auth client backend

src/util/support/Safe.ts

@@ -1,5 +1,7 @@
 import {Integer, isInteger} from './types'
 import {ErrorWithContext} from '../error/ErrorWithContext'
+import {JSONState} from './Rehydratable'
+import {isJSON} from './data'
 
 export class Safe {
     protected thrower: (message: string, value: unknown) => never
@@ -22,10 +24,10 @@ export class Safe {
 
     present(): this {
         if ( !this.value && this.value !== 0 && this.value !== false ) {
-            return this
+            this.thrower('Missing value', this.value)
         }
 
-        this.thrower('Missing value', this.value)
+        return this
     }
 
     integer(): Integer {
@@ -51,6 +53,23 @@ export class Safe {
         return String(this.value)
     }
 
+    json(): JSONState {
+        const str = this.string()
+        if ( !isJSON(str) ) {
+            this.thrower('Invalid JSON', str)
+        }
+
+        return JSON.parse(str)
+    }
+
+    or(other: unknown): Safe {
+        if ( !this.value && this.value !== 0 && this.value !== false ) {
+            return new Safe(other)
+        }
+
+        return this
+    }
+
     in<T>(allowed: T[]): T {
         if ( allowed.includes(this.value as any) ) {
             return this.value as T