fix(resolveConfig): change default version to be a constant (non-changeable)

Author: hasezoey

packages/mongodb-memory-server-core/src/util/DryMongoBinary.ts

@@ -1,5 +1,5 @@
 import debug from 'debug';
-import { envToBool, resolveConfig, ResolveConfigVariables } from './resolveConfig';
+import { DEFAULT_VERSION, envToBool, resolveConfig, ResolveConfigVariables } from './resolveConfig';
 import { checkBinaryPermissions, isNullOrUndefined, pathExists } from './utils';
 import * as path from 'path';
 import { arch, homedir, platform } from 'os';
@@ -96,7 +96,7 @@ export class DryMongoBinary {
     opts?: DryMongoBinaryOptions
   ): Promise<Required<DryMongoBinaryOptions>> {
     log('generateOptions');
-    const defaultVersion = resolveConfig(ResolveConfigVariables.VERSION) ?? '4.0.25';
+    const defaultVersion = resolveConfig(ResolveConfigVariables.VERSION) ?? DEFAULT_VERSION;
     const ensuredOpts: DryMongoBinaryOptions = isNullOrUndefined(opts)
       ? { version: defaultVersion }
       : opts;

packages/mongodb-memory-server-core/src/util/resolveConfig.ts

@@ -25,9 +25,11 @@ export enum ResolveConfigVariables {
 }
 
 export const ENV_CONFIG_PREFIX = 'MONGOMS_';
+/** This Value exists here, because "defaultValues" can be changed with "setDefaultValue", but this property is constant */
+export const DEFAULT_VERSION = '4.0.25';
 export const defaultValues = new Map<ResolveConfigVariables, string>([
   // apply app-default values here
-  [ResolveConfigVariables.VERSION, '4.0.25'],
+  [ResolveConfigVariables.VERSION, DEFAULT_VERSION],
   [ResolveConfigVariables.PREFER_GLOBAL_PATH, 'true'],
   [ResolveConfigVariables.RUNTIME_DOWNLOAD, 'true'],
   [ResolveConfigVariables.USE_HTTP, 'false'],