use const instead of magic string

Author: jhendrixMSFT

packages/typespec-rust/src/codegen/helpers.ts

@@ -8,10 +8,13 @@ import { Use } from './use.js';
 import * as rust from '../codemodel/index.js';
 import * as utils from '../utils/utils.js';
 
+/** the key phrase used in the generated code header */
+export const generatedCodeKeyPhrase = 'Rust Code Generator';
+
 const headerText = `// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 //
-// Code generated by Microsoft (R) Rust Code Generator.`;
+// Code generated by Microsoft (R) ${generatedCodeKeyPhrase}.`;
 
 export const AnnotationNonExhaustive = '#[non_exhaustive]\n';
 

packages/typespec-rust/src/emitter.ts

@@ -7,6 +7,7 @@
 
 import { CodeGenerator } from './codegen/codeGenerator.js';
 import { CodegenError } from './codegen/errors.js';
+import { generatedCodeKeyPhrase } from './codegen/helpers.js';
 import { Adapter, AdapterError, ExternalError } from './tcgcadapter/adapter.js';
 import { reportDiagnostic, RustEmitterOptions } from './lib.js';
 import { execSync } from 'child_process';
@@ -188,5 +189,5 @@ function shouldRmDir(dirName: string): boolean {
     return false;
   }
   const content = fs.readFileSync(modRs, { encoding: 'utf-8' });
-  return content.match(/Rust Code Generator/) !== null;
+  return content.match(generatedCodeKeyPhrase) !== null;
 }