Complete Task Behavior In ServiceTask Entity: A How-To Guide

by Alex Johnson 61 views

This article provides a comprehensive guide on adding complete task behavior to the ServiceTask entity. This functionality involves updating the task status, recording completion timestamps, storing work summaries, and implementing necessary validations. This guide will walk you through the steps, domain invariants, and acceptance criteria to ensure successful implementation. It is essential to understand the importance of task management within any technician operation, and this enhancement directly contributes to that efficiency.

Task Overview

The primary objective is to enhance the ServiceTask entity by adding the capability to complete a task along with a work summary. This is crucial for tracking task progress, maintaining accountability, and providing context for completed tasks. This enhancement is related to Story #21, falls under the Technician Operations bounded context, and involves domain concepts such as TaskCompleted event, CompleteTask command, and WorkSummary value object. This task depends on #358 (TASK-021) and has an estimated time of 2 hours.

What to Do: Step-by-Step Implementation

To achieve the desired functionality, follow these steps:

1. Add completeTask(workSummary) Method to ServiceTask Entity

The first step involves adding a completeTask(workSummary) method to the ServiceTask entity. This method will serve as the entry point for initiating the task completion process. The method should accept a workSummary parameter, which will contain details about the work performed during the task. This is where the core logic for completing a task will reside. Ensure that the method signature is clear and well-documented.

public void completeTask(String workSummary) {
    // Implementation details here
}

2. Update Task Status from IN_PROGRESS to COMPLETED

Inside the completeTask method, the next step is to update the task status from IN_PROGRESS to COMPLETED. This change reflects the current state of the task. It's important to use an enumeration or a defined set of constants for task statuses to maintain consistency and avoid string literals. This status update is a critical indicator for task progress and should be handled carefully.

this.status = TaskStatus.COMPLETED;

3. Record completedAt Timestamp When Status Changes

Upon updating the task status, it's essential to record the timestamp when the task was completed. This timestamp provides valuable information about when the task was finished and can be used for reporting, analysis, and auditing purposes. Store the timestamp in a dedicated field, such as completedAt, within the ServiceTask entity. Using Instant.now() or a similar method is recommended for capturing the current timestamp. This timestamp is a crucial piece of metadata for each task.

this.completedAt = Instant.now();

4. Store workSummary Field on the Task

The workSummary provided as a parameter to the completeTask method should be stored within the ServiceTask entity. This summary provides context and details about the work performed during the task. It can include information such as actions taken, issues encountered, and resolutions applied. The workSummary can be a simple string or a more structured object, depending on the complexity of the required information. This is where the details of the work performed are captured.

this.workSummary = workSummary;

5. Add Validation: Can Only Complete Task with IN_PROGRESS Status

To ensure data integrity and prevent unintended state transitions, add validation logic to the completeTask method. The validation should check if the task status is IN_PROGRESS before allowing the completion process to proceed. If the task is not in the IN_PROGRESS state, an exception or appropriate error message should be thrown. This validation is essential to maintain the integrity of the task lifecycle.

if (this.status != TaskStatus.IN_PROGRESS) {
    throw new IllegalStateException("Task cannot be completed unless it is in IN_PROGRESS status.");
}

6. Write Unit Tests for Completion Behavior

Thorough unit tests are crucial to ensure that the completion behavior is implemented correctly and that all domain invariants are respected. Write tests to cover various scenarios, such as:

  • Completing a task with IN_PROGRESS status.
  • Attempting to complete a task with a status other than IN_PROGRESS.
  • Verifying that the status is updated to COMPLETED.
  • Verifying that the completedAt timestamp is recorded.
  • Verifying that the workSummary is stored correctly.

These unit tests serve as a safety net to catch any regressions or unexpected behavior.

Domain Invariants to Respect

Domain invariants are business rules that must always hold true within the application. When implementing the complete task behavior, the following invariants must be respected:

  1. Task can only be completed if the status is IN_PROGRESS: This ensures that a task cannot be completed multiple times or in an invalid state.
  2. Completing task updates status to COMPLETED: This reflects the correct state transition of the task.
  3. Work summary is stored with the task: This provides context and details about the work performed.
  4. Completed timestamp is recorded: This provides a record of when the task was finished.

Acceptance Criteria

The acceptance criteria define the conditions that must be met for the task to be considered complete. These criteria serve as a checklist for verifying the implementation. The acceptance criteria for adding complete task behavior to the ServiceTask entity are:

  • Code runs without errors: The code should compile and execute without any runtime exceptions.
  • Task can transition from IN_PROGRESS to COMPLETED: The task status should be updated correctly upon completion.
  • Work summary stored on the task: The provided work summary should be persisted with the task.
  • Ready for next task to build on this: The implementation should be complete and well-tested, allowing subsequent tasks to build upon it.

Definition of Done

The definition of done (DoD) outlines the conditions that must be met before a task is considered finished. The DoD provides a clear understanding of what it means for a task to be complete and ensures that all necessary steps have been taken. The definition of done for this task includes:

  • Code committed to the repository: The code changes should be committed to the version control system.
  • Acceptance criteria verified: All acceptance criteria should be met and verified.
  • Domain concepts correctly implemented: The domain concepts related to task completion should be implemented accurately.

Conclusion

Adding complete task behavior to the ServiceTask entity is a crucial enhancement for technician operations. By following the steps outlined in this guide, you can ensure that the implementation is correct, robust, and respects the domain invariants. Remember to write thorough unit tests and verify the acceptance criteria to ensure that the task is complete and ready for the next steps. This functionality will significantly improve task tracking, accountability, and the overall efficiency of technician operations. Explore more about Technician Operations to deepen your understanding of this critical field.