Named jobs in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a named job in a NestJS Bull queue.

NestJS

this.queue.add('[1]', { data: payload });

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

Adefault

BsendEmail

Cjob

Dprocess

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'process' as job name which is a method name, not a job name.

Omitting the job name string.

The first argument to add is the job name, here 'sendEmail'.

2fill in blank

medium

Complete the code to process a named job in a NestJS Bull processor.

NestJS

@Processor('email')
export class EmailProcessor {
  @Process('[1]')
  handleSendEmail(job: Job) {
    // handle job
  }
}

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

Adefault

BemailJob

Cprocess

DsendEmail

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different job name than the one used when adding the job.

Using method names instead of job names in the decorator.

The @Process decorator takes the job name to handle, matching the name used when adding the job.

3fill in blank

hard

Fix the error in the code to correctly add a named job with options.

NestJS

this.queue.add([1], payload, { repeat: { cron: '0 0 * * *' } });

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

A'sendEmail'

BsendEmail

C'process'

Dprocess

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to put quotes around the job name string.

Using variable names instead of string literals.

The job name must be a string, so it needs quotes around it.

4fill in blank

hard

Fill both blanks to define and process a named job in NestJS Bull.

NestJS

this.queue.add('[1]', { userId: 123 });

@Processor('notifications')
export class NotificationProcessor {
  @Process('[2]')
  handleNotification(job: Job) {
    // process notification
  }
}

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

AsendNotification

BsendEmail

Attempts:

3 left

💡 Hint

Common Mistakes

Using different job names for adding and processing.

Mixing job names like 'sendEmail' and 'sendNotification'.

The job name must be the same when adding and processing. Here, 'sendNotification' is used consistently.

5fill in blank

hard

Fill all three blanks to add a named job with options and process it in NestJS Bull.

NestJS

this.queue.add('[1]', { orderId: 456 }, { delay: [2] });

@Processor('orders')
export class OrderProcessor {
  @Process('[3]')
  handleOrder(job: Job) {
    // process order
  }
}

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

AprocessOrder

B5000

DsendOrder

Attempts:

3 left

💡 Hint

Common Mistakes

Using different job names in add and process.

Putting delay as a string instead of a number.

Omitting the delay option.

The job name 'processOrder' is used consistently. The delay option is a number in milliseconds (5000 = 5 seconds).

Practice

1. What is the main benefit of using named jobs in NestJS queues?

easy

A. They automatically speed up job processing.

B. They help identify and manage specific background tasks easily.

C. They encrypt job data for security.

D. They allow jobs to run without a queue.

Solution

1. Step 1: Understand the purpose of named jobs

   Named jobs provide a clear label to background tasks, making them easier to find and manage.

2. Step 2: Compare options with the purpose

   Only They help identify and manage specific background tasks easily. matches this purpose. Options B, C, and D describe unrelated features.

3. Final Answer:

   They help identify and manage specific background tasks easily. -> Option B

4. Quick Check:

   Named jobs = easier management [OK]

Hint: Named jobs label tasks for easy tracking [OK]

Common Mistakes:

• Thinking named jobs improve speed
• Confusing named jobs with security features
• Assuming named jobs remove the need for queues

2. Which of the following is the correct way to add a named job to a queue in NestJS?

easy

A. queue.pushJob('emailJob', { to: '[e-mail]' });

B. queue.createJob('emailJob', { to: '[e-mail]' });

C. queue.runJob('emailJob', { to: '[e-mail]' });

D. queue.add('emailJob', { to: '[e-mail]' });

Solution

1. Step 1: Recall the NestJS queue method for adding jobs

   The correct method to add a job with a name is queue.add(name, data).

2. Step 2: Match the method with options

   Only queue.add('emailJob', { to: '[e-mail]' }); uses queue.add with a job name and data correctly.

3. Final Answer:

   queue.add('emailJob', { to: '[e-mail]' }); -> Option D

4. Quick Check:

   Use queue.add(name, data) [OK]

Hint: Use queue.add('jobName', data) to name jobs [OK]

Common Mistakes:

• Using non-existent methods like createJob or pushJob
• Forgetting to pass the job name as first argument
• Confusing job execution with job creation

3. Given this code snippet, what will be the output when checking the job name?

const job = await queue.add('reportGeneration', { userId: 42 });
console.log(job.name);

medium

A. 'reportGeneration'

B. 'default'

C. undefined

D. Throws an error

Solution

1. Step 1: Understand job creation with a name

   When adding a job with queue.add('reportGeneration', data), the job's name property is set to 'reportGeneration'.

2. Step 2: Check the console.log output

   Logging job.name will print 'reportGeneration'.

3. Final Answer:

   'reportGeneration' -> Option A

4. Quick Check:

   Job name property = 'reportGeneration' [OK]

Hint: Job.name matches the string passed to queue.add [OK]

Common Mistakes:

• Assuming default name is used if a name is given
• Expecting undefined if name is not accessed properly
• Thinking job creation throws error without processor

4. Identify the error in this NestJS queue job addition:

queue.add({ name: 'cleanupJob' }, { force: true });

medium

A. Job name should be a string, not inside an object.

B. The second argument must be a string, not an object.

C. The method add() does not exist on queue.

D. The job data cannot contain boolean values.

Solution

1. Step 1: Review the correct syntax for named jobs

   The queue.add method expects the first argument as a string name, not an object.

2. Step 2: Analyze the given code

   The code passes an object { name: 'cleanupJob' } instead of a string, causing a syntax error.

3. Final Answer:

   Job name should be a string, not inside an object. -> Option A

4. Quick Check:

   First argument to add() = string name [OK]

Hint: Pass job name as string, not object, to queue.add [OK]

Common Mistakes:

• Passing job name inside an object instead of string
• Confusing job data with job name argument
• Assuming add() method is missing or invalid

5. You want to cancel all jobs named 'emailNotification' in a queue. Which approach correctly uses named jobs to achieve this?

hard

A. Restart the queue to clear all jobs named 'emailNotification'.

B. Call queue.removeJobs('emailNotification') directly without fetching jobs.

C. Use queue.getJobs(['emailNotification']) and then call remove() on each job.

D. Filter jobs by data property { type: 'emailNotification' } and delete them.

Solution

1. Step 1: Understand how to retrieve named jobs

   Named jobs can be fetched using queue.getJobs(['jobName']) which returns jobs with that name.

2. Step 2: Remove each fetched job

   After fetching, calling remove() on each job deletes them from the queue.

3. Final Answer:

   Use queue.getJobs(['emailNotification']) and then call remove() on each job. -> Option C

4. Quick Check:

   Fetch named jobs then remove [OK]

Hint: Fetch named jobs first, then remove them one by one [OK]

Common Mistakes:

• Trying to remove jobs by name without fetching them
• Filtering jobs by data instead of name
• Restarting queue does not selectively remove jobs