encore-go-code-review

★ 25

by encoredev · part of encoredev/skills

Review existing Encore Go code for best practices and common anti-patterns.

🔥🔥✓ VerifiedFreeQuick setup

🧩 One of 7 skills in the encoredev/skills package — works on its own, and pairs well with its siblings.

This is the playbook your agent receives when the skill activates — you don't need to read it to use the skill, but it's here to audit before installing.

Encore Go Code Review

Instructions

When reviewing Encore Go code, check for these common issues:

Critical Issues

1. Infrastructure Inside Functions

// WRONG: Infrastructure declared inside function
func setup() {
    db := sqldb.NewDatabase("mydb", sqldb.DatabaseConfig{...})
    topic := pubsub.NewTopic[*Event](https://github.com/encoredev/skills/blob/main/encore/go-code-review/"events", pubsub.TopicConfig{...})
}

// CORRECT: Package level declaration
var db = sqldb.NewDatabase("mydb", sqldb.DatabaseConfig{
    Migrations: "./migrations",
})

var topic = pubsub.NewTopic[*Event](https://github.com/encoredev/skills/blob/main/encore/go-code-review/"events", pubsub.TopicConfig{
    DeliveryGuarantee: pubsub.AtLeastOnce,
})

2. Missing Context Parameter

// WRONG: Missing context
//encore:api public method=GET path=/users/:id
func GetUser(params *GetUserParams) (*User, error) {
    // ...
}

// CORRECT: Context as first parameter
//encore:api public method=GET path=/users/:id
func GetUser(ctx context.Context, params *GetUserParams) (*User, error) {
    // ...
}

3. SQL Injection Risk

// WRONG: String interpolation
query := fmt.Sprintf("SELECT * FROM users WHERE email = '%s'", email)
rows, err := db.Query(ctx, query)

// CORRECT: Parameterized query
rows, err := sqldb.Query[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, `
    SELECT * FROM users WHERE email = $1
`, email)

4. Wrong Return Types

// WRONG: Returning non-pointer struct
//encore:api public method=GET path=/users/:id
func GetUser(ctx context.Context, params *GetUserParams) (User, error) {
    // ...
}

// CORRECT: Return pointer to struct
//encore:api public method=GET path=/users/:id
func GetUser(ctx context.Context, params *GetUserParams) (*User, error) {
    // ...
}

5. Ignoring Errors

// WRONG: Ignoring error
user, _ := sqldb.QueryRow[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, query, id)

// CORRECT: Handle error
user, err := sqldb.QueryRow[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, query, id)
if err != nil {
    return nil, err
}

Warning Issues

6. Not Checking for ErrNoRows

// RISKY: Returns nil without proper error
func getUser(ctx context.Context, id string) (*User, error) {
    user, err := sqldb.QueryRow[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, `
        SELECT * FROM users WHERE id = $1
    `, id)
    if err != nil {
        return nil, err  // ErrNoRows returns generic error
    }
    return user, nil
}

// BETTER: Check for not found specifically
import "errors"

func getUser(ctx context.Context, id string) (*User, error) {
    user, err := sqldb.QueryRow[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, `
        SELECT * FROM users WHERE id = $1
    `, id)
    if errors.Is(err, sqldb.ErrNoRows) {
        return nil, &errs.Error{
            Code:    errs.NotFound,
            Message: "user not found",
        }
    }
    if err != nil {
        return nil, err
    }
    return user, nil
}

7. Public Internal Endpoints

// CHECK: Should this cron endpoint be public?
//encore:api public method=POST path=/internal/cleanup
func CleanupJob(ctx context.Context) error {
    // ...
}

// BETTER: Use private for internal endpoints
//encore:api private
func CleanupJob(ctx context.Context) error {
    // ...
}

8. Non-Idempotent Subscription Handlers

// RISKY: Not idempotent (pubsub has at-least-once delivery)
var _ = pubsub.NewSubscription(OrderCreated, "process-order",
    pubsub.SubscriptionConfig[*OrderCreatedEvent]{
        Handler: func(ctx context.Context, event *OrderCreatedEvent) error {
            return chargeCustomer(ctx, event.OrderID)  // Could charge twice!
        },
    },
)

// SAFER: Check before processing
var _ = pubsub.NewSubscription(OrderCreated, "process-order",
    pubsub.SubscriptionConfig[*OrderCreatedEvent]{
        Handler: func(ctx context.Context, event *OrderCreatedEvent) error {
            order, err := getOrder(ctx, event.OrderID)
            if err != nil {
                return err
            }
            if order.Status != "pending" {
                return nil  // Already processed
            }
            return chargeCustomer(ctx, event.OrderID)
        },
    },
)

9. Not Closing Query Rows

// WRONG: Rows not closed
func listUsers(ctx context.Context) ([]*User, error) {
    rows, err := sqldb.Query[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, `SELECT * FROM users`)
    if err != nil {
        return nil, err
    }
    // Missing: defer rows.Close()
    
    var users []*User
    for rows.Next() {
        users = append(users, rows.Value())
    }
    return users, nil
}

// CORRECT: Always close rows
func listUsers(ctx context.Context) ([]*User, error) {
    rows, err := sqldb.Query[User](https://github.com/encoredev/skills/blob/main/encore/go-code-review/ctx, db, `SELECT * FROM users`)
    if err != nil {
        return nil, err
    }
    defer rows.Close()
    
    var users []*User
    for rows.Next() {
        users = append(users, rows.Value())
    }
    return users, rows.Err()
}

Review Checklist

Output Format

When reviewing, report issues as:

[CRITICAL] [file:line] Description of issue
[WARNING] [file:line] Description of concern  
[GOOD] Notable good practice observed