swagger-jsdoc setup in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import swagger-jsdoc in an Express app.

Express

const swaggerJSDoc = require('[1]');

Drag options to blanks, or click blank then click option'

Aswagger-ui-express

Bexpress

Cswagger-jsdoc

Dbody-parser

Attempts:

3 left

💡 Hint

Common Mistakes

Importing 'express' instead of 'swagger-jsdoc'.

Using 'swagger-ui-express' which is for UI, not spec generation.

The swagger-jsdoc package is imported to generate Swagger specification from JSDoc comments.

2fill in blank

medium

Complete the code to define the swagger-jsdoc options object.

Express

const options = {
  definition: {
    openapi: '[1]',
    info: {
      title: 'API Docs',
      version: '1.0.0'
    }
  },
  apis: ['./routes/*.js']
};

Drag options to blanks, or click blank then click option'

A2.0

B3.0.0

C1.0

Dlatest

Attempts:

3 left

💡 Hint

Common Mistakes

Using '2.0' which is an older Swagger version.

Using 'latest' which is not a valid version string.

The OpenAPI version 3.0.0 is the current standard for swagger-jsdoc definitions.

3fill in blank

hard

Fix the error in creating the swaggerSpec variable.

Express

const swaggerSpec = swaggerJSDoc([1]);

Drag options to blanks, or click blank then click option'

Aoptions

BswaggerOptions

Cconfig

Doptions()

Attempts:

3 left

💡 Hint

Common Mistakes

Calling options as a function when it is an object.

Passing a wrong variable name.

The swaggerJSDoc function expects the options object, not a function call.

4fill in blank

hard

Fill both blanks to set up swagger-ui-express middleware in Express.

Express

const swaggerUi = require('[1]');
app.use('/api-docs', swaggerUi.[2](swaggerSpec));

Drag options to blanks, or click blank then click option'

Aswagger-ui-express

Bswagger-jsdoc

Csetup

Dserve

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'swagger-jsdoc' instead of 'swagger-ui-express'.

Using 'serve' instead of 'setup' for the middleware that takes the spec.

swagger-ui-express is used to serve the Swagger UI, and setup is the middleware to initialize it with the spec.

5fill in blank

hard

Fill all three blanks to complete the swagger-jsdoc setup and serve docs at '/docs'.

Express

const swaggerUi = require('[1]');
const swaggerSpec = swaggerJSDoc([2]);
app.use('[3]', swaggerUi.serve, swaggerUi.setup(swaggerSpec));

Drag options to blanks, or click blank then click option'

Aswagger-ui-express

Boptions

C/docs

Dswagger-jsdoc

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up package names.

Using wrong route path like '/api-docs'.

Import swagger-ui-express, pass the options object to swaggerJSDoc, and serve the docs at /docs.

Practice

1. What is the main purpose of swagger-jsdoc in an Express app?

easy

A. To connect to a database

B. To handle HTTP requests and responses

C. To generate API documentation from comments in your code

D. To serve static files like images and CSS

Solution

1. Step 1: Understand swagger-jsdoc role

   swagger-jsdoc reads specially formatted comments in your Express code to create API documentation automatically.

2. Step 2: Compare with other options

   Handling HTTP requests is Express's job, not swagger-jsdoc. Database connection and serving static files are unrelated tasks.

3. Final Answer:

   To generate API documentation from comments in your code -> Option C

4. Quick Check:

   swagger-jsdoc = API docs generator [OK]

Hint: swagger-jsdoc creates docs from code comments [OK]

Common Mistakes:

• Confusing swagger-jsdoc with Express routing
• Thinking swagger-jsdoc manages databases
• Assuming swagger-jsdoc serves static files

2. Which of the following is the correct way to import and initialize swagger-jsdoc in an ES modules-based Express app?

easy

A. import swaggerJSDoc from 'swagger-jsdoc'; const specs = swaggerJSDoc(options);

B. const swaggerJSDoc = require('swagger-jsdoc'); const specs = swaggerJSDoc();

C. const swaggerJSDoc = require('swagger-jsdoc'); const specs = swaggerJSDoc(options);

D. import swaggerJSDoc from 'swagger-jsdoc'; const specs = swaggerJSDoc();

Solution

1. Step 1: Use modern ES module import

   In modern Express apps using ES modules, import swaggerJSDoc from 'swagger-jsdoc' is correct.

2. Step 2: Initialize swagger-jsdoc with options

   swaggerJSDoc requires an options object to generate specs, so calling it without arguments is incorrect.

3. Final Answer:

   import swaggerJSDoc from 'swagger-jsdoc'; const specs = swaggerJSDoc(options); -> Option A

4. Quick Check:

   Import + call with options = C [OK]

Hint: Use import and pass options to swaggerJSDoc() [OK]

Common Mistakes:

• Calling swaggerJSDoc() without options
• Using require instead of import in ES modules
• Not assigning the result to a variable

3. Given this swagger-jsdoc options object, what will specs contain after calling swaggerJSDoc(options)?

const options = {
  definition: {
    openapi: '3.0.0',
    info: { title: 'Test API', version: '1.0.0' }
  },
  apis: ['./routes/*.js']
};
const specs = swaggerJSDoc(options);

medium

A. A string containing raw JavaScript code from './routes/*.js'

B. An object with OpenAPI info and paths extracted from comments in './routes/*.js'

C. An error because 'apis' path is incorrect

D. An empty object because no API comments exist

Solution

1. Step 1: Understand swagger-jsdoc output

   swagger-jsdoc returns a JSON object with OpenAPI info and paths parsed from specified files.

2. Step 2: Check options correctness

   The options specify OpenAPI version and info, and a valid path pattern for API files, so it will parse comments there.

3. Final Answer:

   An object with OpenAPI info and paths extracted from comments in './routes/*.js' -> Option B

4. Quick Check:

   swaggerJSDoc(options) = OpenAPI JSON object [OK]

Hint: swaggerJSDoc returns parsed OpenAPI JSON from code comments [OK]

Common Mistakes:

• Expecting raw code instead of parsed JSON
• Assuming error without checking file existence
• Thinking output is empty without comments

4. Identify the error in this swagger-jsdoc setup snippet:

import swaggerJSDoc from 'swagger-jsdoc';
import swaggerUi from 'swagger-ui-express';
const options = {
  definition: {
    openapi: '3.0.0',
    info: { title: 'API', version: '1.0' }
  },
  apis: ['./api/*.js']
};
const specs = swaggerJSDoc();

app.use('/docs', swaggerUi.serve, swaggerUi.setup(specs));

medium

A. swaggerJSDoc is called without passing the options object

B. The 'apis' path should be './api/*.ts' instead of '.js'

C. swaggerUi.setup() should be called before swaggerUi.serve

D. Missing import for swaggerUi from 'swagger-ui-express'

Solution

1. Step 1: Check swaggerJSDoc call

   The code calls swaggerJSDoc() without arguments, but it requires the options object to generate specs.

2. Step 2: Verify other parts

   The 'apis' path is valid for JavaScript files. swaggerUi.setup() after serve is correct usage.

3. Final Answer:

   swaggerJSDoc is called without passing the options object -> Option A

4. Quick Check:

   Call swaggerJSDoc(options) not empty () [OK]

Hint: Always pass options to swaggerJSDoc() [OK]

Common Mistakes:

• Calling swaggerJSDoc() without options
• Confusing order of swaggerUi middleware
• Ignoring missing imports

5. You want to set up swagger-jsdoc in your Express app to document APIs ONLY in routes/users.js and routes/products.js (assuming there are other .js files in the routes directory that should not be documented). Which apis option correctly includes both files for swagger-jsdoc?

hard

A. ['./routes/users.js', './routes/products']

B. ['./routes/*.js']

C. ['./routes/users.js|./routes/products.js']

D. ['./routes/users.js', './routes/products.js']

Solution

1. Step 1: Understand 'apis' option format

   The 'apis' option is an array of file paths or glob patterns to scan for comments.

2. Step 2: Check each option

   ['./routes/users.js', './routes/products.js'] lists both files explicitly, which is correct. ['./routes/*.js'] uses a glob that includes both files but may include others. ['./routes/users.js|./routes/products.js'] uses an invalid string with '|'. ['./routes/users.js', './routes/products'] has a missing file extension for products.js.

3. Final Answer:

   ['./routes/users.js', './routes/products.js'] -> Option D

4. Quick Check:

   List each file path separately in array [OK]

Hint: List each file path separately in 'apis' array [OK]

Common Mistakes:

• Using invalid string with '|' instead of array items
• Omitting file extensions
• Using too broad glob patterns unintentionally