Add solution for Challenge 13 by Kosench

[Kosench]

Challenge 13 Solution

Submitted by: @Kosench
Challenge: Challenge 13

Description

This PR contains my solution for Challenge 13.

Changes

• Added solution file to challenge-13/submissions/Kosench/solution-template.go

Testing

• Solution passes all test cases
• Code follows Go best practices

Thank you for reviewing my submission! 🚀

[coderabbitai]

Walkthrough

Adds a SQLite-backed ProductStore in Go: defines Product and ProductStore, provides InitDB with schema creation, NewProductStore, full CRUD (Create/Get/Update/Delete), ListProducts (optional category filter), BatchUpdateInventory within a transaction, and a main scaffold.

Changes

Cohort / File(s)

Summary

Product Inventory System Implementation challenge-13/submissions/Kosench/solution-template.go

Adds Product (ID, Name, Price, Quantity, Category) and ProductStore (*sql.DB), InitDB with products table schema and constraints, NewProductStore, CRUD methods (CreateProduct, GetProduct, UpdateProduct, DeleteProduct), ListProducts(category string), BatchUpdateInventory(updates map[int64]int) performing transactional updates with per-item validation and rollback, error wrapping, and a main() scaffold.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

• Review transaction correctness and rollback paths in BatchUpdateInventory
• Verify parameterized queries and filter handling in ListProducts
• Confirm validation of price/quantity (≥ 0) and RowsAffected checks for updates/deletes
• Inspect InitDB for proper connection handling and schema constraints

Possibly related PRs

• Add solution for Challenge 27 #55 — Adds an SQLite-backed Product/ProductStore implementation with matching types and CRUD/BatchUpdate methods.
• Add solution for Challenge 13 by berkkaradalan #793 — Implements the same ProductStore types and methods (InitDB, NewProductStore, CRUD, ListProducts, BatchUpdateInventory).
• Add solution for Challenge 13 by nzamulov #605 — Adds an identical SQLite-backed ProductStore implementation including transactional batch inventory updates.

Pre-merge checks

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: adding a Challenge 13 solution by Kosench. It is concise, specific, and clearly conveys the primary purpose of the PR.
Description check	✅ Passed	The description is well-related to the changeset, clearly explaining that it adds a Challenge 13 solution with supporting details about testing and code practices.

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 7820c4e and 57c9468.

📒 Files selected for processing (1)

• challenge-13/submissions/Kosench/solution-template.go (1 hunks)

🚧 Files skipped from review as they are similar to previous changes (1)

• challenge-13/submissions/Kosench/solution-template.go

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Actionable comments posted: 3

🧹 Nitpick comments (1)

challenge-13/submissions/Kosench/solution-template.go (1)

95-100: Wrap the error for consistency.

Non-ErrNoRows errors are returned unwrapped, which is inconsistent with the rest of the codebase and loses context about where the error originated.

 	if err != nil {
 		if errors.Is(err, sql.ErrNoRows) {
 			return nil, fmt.Errorf("product with ID %d not found", id)
 		}
-		return nil, err
+		return nil, fmt.Errorf("failed to get product: %w", err)
 	}

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 560ce41 and 7820c4e.

📒 Files selected for processing (1)

• challenge-13/submissions/Kosench/solution-template.go (1 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

challenge-13/submissions/Kosench/solution-template.go (2)

challenge-13/submissions/Gandook/solution-template.go (1)

• ID (144-144)

challenge-13/submissions/Ali-Fartoot/solution-template.go (1)

• DB (29-29)

🔇 Additional comments (6)

challenge-13/submissions/Kosench/solution-template.go (6)

1-28: LGTM!

The package structure, imports, and type definitions are clean and idiomatic. The anonymous import for the SQLite driver and the struct designs follow Go conventions.

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61-81: LGTM!

The CreateProduct implementation correctly inserts the product, retrieves the auto-generated ID, and updates the passed product struct. Error handling is appropriate.

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105-134: LGTM!

The UpdateProduct implementation correctly updates all fields and validates that a row was actually affected, providing proper not-found detection.

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136-155: LGTM!

The DeleteProduct implementation correctly handles the delete operation and validates that a row was actually deleted.

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157-197: LGTM!

Good implementation with proper handling of the optional category filter. The defer rows.Close() and rows.Err() check after iteration are correct practices for preventing resource leaks and catching iteration errors.

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238-240: LGTM!

The empty main function is appropriate for a solution template that will be tested externally.