Merge pull request #1447 from micalevisk/fix/issue-1444

fix(utils): when updating a non-existing nestjs module

Author: kamilmysliwiec

src/utils/metadata.manager.ts

@@ -24,14 +24,18 @@ export class MetadataManager {
     metadata: string,
     symbol: string,
     staticOptions?: DeclarationOptions['staticOptions'],
-  ): string {
+  ): string | undefined {
     const source: SourceFile = createSourceFile(
       'filename.ts',
       this.content,
       ScriptTarget.ES2017,
     );
     const decoratorNodes: Node[] = this.getDecoratorMetadata(source, '@Module');
     const node: Node = decoratorNodes[0];
+    // If there is no occurrence of `@Module` decorator, nothing will be inserted
+    if (!node) {
+      return;
+    }
     const matchingProperties: ObjectLiteralElement[] = (
       node as ObjectLiteralExpression
     ).properties

src/utils/module-metadata.declarator.ts

@@ -9,6 +9,6 @@ export class ModuleMetadataDeclarator {
       options.symbol,
       options.staticOptions,
     );
-    return inserted;
+    return inserted ?? content;
   }
 }

test/utils/metadata.manager.test.ts

@@ -344,4 +344,14 @@ describe('Metadata Manager', () => {
       'export class FooModule {}\n'
     );
   });
+  it('should return undefined if there is no metadata to update', () => {
+    const metadata = 'imports';
+    const symbol = 'FooModule';
+    const manager = new MetadataManager(
+      'import { Module } from \'@nestjs/common\';\n' +
+      '\n' +
+      'export class FooModule {}\n'
+    );
+    expect(manager.insert(metadata, symbol)).toEqual(undefined);
+  });
 });