From cc100d632c21f4fb1d63ba3f8d6d230b1b548d22 Mon Sep 17 00:00:00 2001
From: topchetoeu <36534413+TopchetoEU@users.noreply.github.com>
Date: Thu, 29 Jun 2023 17:25:45 +0300
Subject: [PATCH] feat: add literals to schema converter

---
 src/server/decorators/schema.ts | 55 ++++++++++++++++++++++++++-------
 1 file changed, 44 insertions(+), 11 deletions(-)

diff --git a/src/server/decorators/schema.ts b/src/server/decorators/schema.ts
index 050cd5a..8ad8f1a 100644
--- a/src/server/decorators/schema.ts
+++ b/src/server/decorators/schema.ts
@@ -3,11 +3,15 @@ import { UUID } from "https://deno.land/x/mongo@v0.31.2/mod.ts";
 import HttpError from "../HttpError.ts";
 import { makeParameterModifier } from "../Router.ts";
 
-export type PrimitiveSchema = 'string' | 'number' | 'boolean' | 'uuid' | 'object';
-export type OptionalSchema<T extends PrimitiveSchema = PrimitiveSchema> = `${T}?`;
+export type PrimitiveSchema = number | 'any' | 'undefined' | 'null' | 'string' | 'number' | 'boolean' | 'true' | 'false' | 'uuid' | 'object';
+export type OptionalSchema<T extends PrimitiveSchema | number = PrimitiveSchema> = `${T}?`;
+export type LiteralSchema<T extends string = string> = `:${T}`;
+export type OptionalLiteralSchema<T extends string = string> = `:${T}?`;
 export type ObjectSchema =  { $optional?: boolean; } & { [key: string]: Schema };
 export type OrSchema =  [] | [Schema] | [Schema, Schema] | [Schema, Schema, Schema];
-export type Schema = 'any' | 'null' | PrimitiveSchema | OptionalSchema | OrSchema | ObjectSchema;
+export type Schema =
+    PrimitiveSchema | OptionalSchema | OrSchema | ObjectSchema |
+    LiteralSchema | OptionalLiteralSchema;
 
 export type ObjectSchemaType<T extends ObjectSchema> =
     ({ [x in keyof T]: SchemaType<T[x]> }) |
@@ -15,11 +19,17 @@ export type ObjectSchemaType<T extends ObjectSchema> =
 export type SchemaType<T extends Schema> =
     T extends 'any' ? any :
     T extends 'null' ? null :
+    T extends 'undefined' ? undefined :
     T extends 'string' ? string :
     T extends 'number' ? number :
     T extends 'boolean' ? boolean :
     T extends 'uuid' ? UUID :
+    T extends 'true' ? true :
+    T extends 'false' ? false :
+    T extends number ? T :
     T extends OptionalSchema<infer T> ? SchemaType<T> | undefined :
+    T extends LiteralSchema<infer T> ? T :
+    T extends OptionalLiteralSchema<infer T> ? T | undefined :
     T extends [] ? never :
     T extends [Schema] ? SchemaType<T[0]> :
     T extends [Schema, Schema] ? SchemaType<T[0]> | SchemaType<T[1]> :
@@ -29,6 +39,7 @@ export type SchemaType<T extends Schema> =
 
 function stringify(desc: Schema): string {
     if (typeof desc === 'string') return desc;
+    if (typeof desc === 'number') return desc.toString();
     if (desc instanceof Array) return desc.map(stringify).join(' | ');
 
     let res = '{ ';
@@ -66,18 +77,28 @@ async function _convert(path: string[], val: unknown, desc: Schema): Promise<any
         if (opt) type = type.substring(0, desc.length - 1);
         if (opt && val === undefined) return val;
 
+        if (type.startsWith(':')) {
+            if (val !== type.substring(1)) return val;
+            else throw new HttpError(`${_path}: Expected ${type.substring(1)}.`);
+        }
+
         switch (type) {
+            case "true":
+                if (val === true) return true;
+                throw new HttpError(`${_path}: Expected true.`);
+            case "false":
+                if (val === false) return false;
+                throw new HttpError(`${_path}: Expected false.`);
             case "null":
                 if (val === null) return null;
                 throw new HttpError(`${_path}: Expected null.`);
+            case "undefined":
+                if (val === undefined) return undefined;
+                throw new HttpError(`${_path}: Expected undefined.`);
             case "string": return val + "";
             case "uuid":
-                try {
-                    return new UUID(val + "");
-                }
-                catch {
-                    throw new HttpError(`${_path}: Expected an uuid or a value, convertible to an uuid.`);
-                }
+                try { return new UUID(val + ""); }
+                catch { throw new HttpError(`${_path}: Expected an uuid or a value, convertible to an uuid.`); }
             case "number": {
                 const res = Number.parseFloat(val + "");
                 if (isNaN(res)) throw new HttpError(`${_path}: Expected a number or a value, convertible to a number.`);
@@ -89,9 +110,21 @@ async function _convert(path: string[], val: unknown, desc: Schema): Promise<any
                 if (res === 'false') return true;
                 throw new HttpError(`${_path}: Expected a boolean or a value, convertible to a boolean.`);
             }
-            default:
-                throw new Error(`${_path}: Unknown type ${type}`);
         }
+
+        const num = Number.parseFloat(type);
+
+        if (!isNaN(num)) {
+            const res = Number.parseFloat(val + "");
+            if (res !== num) throw new HttpError(`${_path}: Expected ${num}.`);
+            return res;
+        }
+
+        throw new Error(`${_path}: Unknown type ${type}`);
+    }
+    else if (typeof desc === 'number') {
+        if (desc === val) return desc;
+        else throw new HttpError(`${_path}: Expected ${desc}.`);
     }
     else if (desc instanceof Array) {
         for (const type of desc) {