perf: added possibility to lazy initialize the document

nestjs · Apr 15, 2023 · c1f7931 · c1f7931
1 parent 5313c38
commit c1f7931
Show file tree

Hide file tree

Showing 2 changed files with 99 additions and 34 deletions.
diff --git a/lib/interfaces/swagger-custom-options.interface.ts b/lib/interfaces/swagger-custom-options.interface.ts
@@ -1,9 +1,20 @@
 import { SwaggerUiOptions } from './swagger-ui-options.interface';
+import { SwaggerDocumentOptions } from './swagger-document-options.interface';
+import { OpenAPIObject } from './open-api-spec.interface';
 
 export interface SwaggerCustomOptions {
   useGlobalPrefix?: boolean;
   explorer?: boolean;
   swaggerOptions?: SwaggerUiOptions;
+  /**
+   * @note Only use when you want to use lazy initialization, if you create the document with `createDocument` you don't need to use this option
+   */
+  documentOptions?: SwaggerDocumentOptions;
+    /**
+   * @note Only use when you want to use lazy initialization, if you create the document with `createDocument` you don't need to use this option
+   * @required when you want to use lazy initialization
+   */
+  openApiConfig?: Omit<OpenAPIObject, 'paths'>;
   customCss?: string;
   customCssUrl?: string | string[];
   customJs?: string | string[];

diff --git a/lib/swagger-module.ts b/lib/swagger-module.ts
@@ -24,22 +24,22 @@ export class SwaggerModule {
   public static createDocument(
     app: INestApplication,
     config: Omit<OpenAPIObject, 'paths'>,
-    options: SwaggerDocumentOptions = {}
+    options: SwaggerDocumentOptions = {},
   ): OpenAPIObject {
     const swaggerScanner = new SwaggerScanner();
     const document = swaggerScanner.scanApplication(app, options);
 
     document.components = assignTwoLevelsDeep(
       {},
       config.components,
-      document.components
+      document.components,
     );
 
     return {
       openapi: '3.0.0',
       paths: {},
       ...config,
-      ...document
+      ...document,
     };
   }
 
@@ -62,24 +62,49 @@ export class SwaggerModule {
   }
 
   private static serveDocuments(
+    app: INestApplication,
     finalPath: string,
     urlLastSubdirectory: string,
     httpAdapter: HttpServer,
-    swaggerInitJS: string,
+    document: OpenAPIObject | undefined,
     options: {
-      html: string;
-      yamlDocument: string;
-      jsonDocument: string;
       jsonDocumentUrl: string;
       yamlDocumentUrl: string;
-    }
+      swaggerOptions: SwaggerCustomOptions,
+    },
   ) {
+    if (!document && !options.swaggerOptions.openApiConfig) {
+      throw new Error(
+        'If you want to use lazy initialization for the document, you must provide the "openApiConfig" option.',
+      );
+    }
+
+    const lazyBuildDocument = () => {
+      return SwaggerModule.createDocument(
+        app,
+        options.swaggerOptions.openApiConfig!,
+        options.swaggerOptions.documentOptions,
+      );
+    }
+
+    const baseUrlForSwaggerUI = normalizeRelPath(`./${urlLastSubdirectory}/`);
+
+    let html: string;
+    let swaggerInitJS: string;
+
     httpAdapter.get(
       normalizeRelPath(`${finalPath}/swagger-ui-init.js`),
       (req, res) => {
         res.type('application/javascript');
+
+        if (!document)
+          document = lazyBuildDocument();
+
+        if (!swaggerInitJS)
+          swaggerInitJS = buildSwaggerInitJS(document, options);
+
         res.send(swaggerInitJS);
-      }
+      },
     );
 
     /**
@@ -89,12 +114,19 @@ export class SwaggerModule {
     try {
       httpAdapter.get(
         normalizeRelPath(
-          `${finalPath}/${urlLastSubdirectory}/swagger-ui-init.js`
+          `${finalPath}/${urlLastSubdirectory}/swagger-ui-init.js`,
         ),
         (req, res) => {
           res.type('application/javascript');
+
+          if (!document)
+            document = lazyBuildDocument();
+
+          if (!swaggerInitJS)
+            swaggerInitJS = buildSwaggerInitJS(document, options);
+
           res.send(swaggerInitJS);
-        }
+        },
       );
     } catch (err) {
       /**
@@ -105,14 +137,28 @@ export class SwaggerModule {
 
     httpAdapter.get(finalPath, (req, res) => {
       res.type('text/html');
-      res.send(options.html);
+
+      if (!document)
+        document = lazyBuildDocument();
+
+      if (!html)
+        html = buildSwaggerHTML(baseUrlForSwaggerUI, document, options);
+
+      res.send(html);
     });
 
     // fastify doesn't resolve 'routePath/' -> 'routePath', that's why we handle it manually
     try {
       httpAdapter.get(normalizeRelPath(`${finalPath}/`), (req, res) => {
         res.type('text/html');
-        res.send(options.html);
+
+        if (!document)
+          document = lazyBuildDocument();
+
+        if (!html)
+          html = buildSwaggerHTML(baseUrlForSwaggerUI, document, options);
+
+        res.send(html);
       });
     } catch (err) {
       /**
@@ -123,33 +169,46 @@ export class SwaggerModule {
        */
     }
 
+    let yamlDocument: string;
+    let jsonDocument: string;
+
     httpAdapter.get(normalizeRelPath(options.jsonDocumentUrl), (req, res) => {
       res.type('application/json');
-      res.send(options.jsonDocument);
+
+      if (!document)
+        document = lazyBuildDocument();
+
+      if (!yamlDocument) jsonDocument = JSON.stringify(document);
+
+      res.send(jsonDocument);
     });
 
     httpAdapter.get(normalizeRelPath(options.yamlDocumentUrl), (req, res) => {
       res.type('text/yaml');
-      res.send(options.yamlDocument);
+
+      if (!document)
+        document = lazyBuildDocument();
+
+      if (!yamlDocument)
+        yamlDocument = jsyaml.dump(document);
+
+      res.send(yamlDocument);
     });
   }
 
   public static setup(
     path: string,
     app: INestApplication,
-    document: OpenAPIObject,
-    options?: SwaggerCustomOptions
+    document?: OpenAPIObject,
+    options?: SwaggerCustomOptions,
   ) {
     const globalPrefix = getGlobalPrefix(app);
     const finalPath = validatePath(
       options?.useGlobalPrefix && validateGlobalPrefix(globalPrefix)
         ? `${globalPrefix}${validatePath(path)}`
-        : path
+        : path,
     );
-    const urlLastSubdirectory = finalPath.split('/').slice(-1).pop();
-
-    const yamlDocument = jsyaml.dump(document, { skipInvalid: true });
-    const jsonDocument = JSON.stringify(document);
+    const urlLastSubdirectory = finalPath.split('/').slice(-1).pop() || '';
 
     const validatedGlobalPrefix =
       options?.useGlobalPrefix && validateGlobalPrefix(globalPrefix)
@@ -164,24 +223,19 @@ export class SwaggerModule {
       ? `${validatedGlobalPrefix}${validatePath(options.yamlDocumentUrl)}`
       : `${finalPath}-yaml`;
 
-    const baseUrlForSwaggerUI = normalizeRelPath(`./${urlLastSubdirectory}/`);
-
-    const html = buildSwaggerHTML(baseUrlForSwaggerUI, document, options);
-    const swaggerInitJS = buildSwaggerInitJS(document, options);
     const httpAdapter = app.getHttpAdapter();
 
     SwaggerModule.serveDocuments(
+      app,
       finalPath,
       urlLastSubdirectory,
       httpAdapter,
-      swaggerInitJS,
+      document,
       {
-        html,
-        yamlDocument,
-        jsonDocument,
         jsonDocumentUrl: finalJSONDocumentPath,
-        yamlDocumentUrl: finalYAMLDocumentPath
-      }
+        yamlDocumentUrl: finalYAMLDocumentPath,
+        swaggerOptions: options || {},
+      },
     );
 
     SwaggerModule.serveStatic(finalPath, app);
@@ -194,8 +248,8 @@ export class SwaggerModule {
      *  serveStaticSlashEndingPath === finalPath when path === '' || path === '/'
      *  in that case we don't need to serve swagger assets on extra sub path
      */
-    if (serveStaticSlashEndingPath !== finalPath) {
+    if (serveStaticSlashEndingPath !== finalPath)
       SwaggerModule.serveStatic(serveStaticSlashEndingPath, app);
-    }
+
   }
 }