feature(microservices): add transformPatternToRoute utility

Author: Geass1000

packages/microservices/utils/msvc.util.ts

@@ -0,0 +1,39 @@
+import { isString, isObject } from '@nestjs/common/utils/shared.utils';
+
+export class MsvcUtil {
+
+    /**
+     * Transforms the Pattern to Route.
+     * 1. If Pattern is a `string`, it will be returned as it is.
+     * 2. If Pattern is a `JSON` object, it will be transformed to Route. For that end,
+     * the function will sort properties of `JSON` Object and creates `route` string
+     * according to the following template:
+     * <key1>:<value1>/<key2>:<value2>/.../<keyN>:<valueN>
+     *
+     * @param  {any} pattern - client pattern
+     * @returns string
+     */
+    public static transformPatternToRoute(pattern: any): string {
+        // Returns the pattern according to the 1st
+        if (isString(pattern)) {
+            return pattern;
+        }
+
+        // Throws the error if the pattern has an incorrect type
+        if (!isObject(pattern)) {
+            throw new Error(`The pattern must be of type 'string' or 'object'!`);
+        }
+
+        // Gets keys of the JSON Pattern and sorts them
+        const sortedKeys = Object.keys(pattern)
+            .sort((a, b) => ('' + a).localeCompare(b));
+
+        // Creates the array of Pattern params from sorted keys and their corresponding values
+        const sortedPatternParams = sortedKeys.map((key) =>
+            `${key}:${pattern[key]}`);
+
+        // Creates and returns the Route
+        const sortedPattern = sortedPatternParams.join('/');
+        return sortedPattern;
+    }
+}