arangolint

Opinionated linter for ArangoDB go driver v2.

arangolint is available in golangci-lint since v2.2.0.

Features

Enforce explicit AllowImplicit in transactions

Why? Because it forces you as a developer to evaluate the need of implicit collections in transactions.

Why should you? Because lazily adding collections to transactions can lead to deadlocks, and because the default is to allow it.

ctx := context.Background()
arangoClient := arangodb.NewClient(nil)
db, _ := arangoClient.GetDatabase(ctx, "name", nil)

// Bad
trx, _ := db.BeginTransaction(ctx, arangodb.TransactionCollections{}, nil) // want "missing AllowImplicit option"
trx, _ = db.BeginTransaction(ctx, arangodb.TransactionCollections{}, &arangodb.BeginTransactionOptions{LockTimeout: 0}) // want "missing AllowImplicit option"

// Good
trx, _ = db.BeginTransaction(ctx, arangodb.TransactionCollections{}, &arangodb.BeginTransactionOptions{AllowImplicit: true})
trx, _ = db.BeginTransaction(ctx, arangodb.TransactionCollections{}, &arangodb.BeginTransactionOptions{AllowImplicit: false})
trx, _ = db.BeginTransaction(ctx, arangodb.TransactionCollections{}, &arangodb.BeginTransactionOptions{AllowImplicit: true, LockTimeout: 0})

// Indirect
options := arangodb.BeginTransactionOptions{LockTimeout: 0}
db.BeginTransaction(ctx, arangodb.TransactionCollections{}, &options) // want "missing AllowImplicit option"
options.AllowImplicit = true
db.BeginTransaction(ctx, arangodb.TransactionCollections{}, &options)

Notes and limitations:

• Intra-procedural only: the analyzer does not follow values across function/method boundaries.
• Flow- and block-sensitive within the current function: prior statements in the nearest block and its ancestor blocks are considered when evaluating a call site.
• What is detected: AllowImplicit set either in a composite literal initialization (e.g., &arangodb.BeginTransactionOptions{AllowImplicit: true}) or via an explicit assignment before the call (e.g., opts.AllowImplicit = ...).
• Conservative by design: when the options value comes from an unknown factory/helper call, arangolint assumes AllowImplicit may be set to avoid false positives.
• Out of scope (for now): inter-procedural tracking, deep control-flow analysis, and inference through complex aliasing beyond simple identifiers and selectors.