sendou.ink/docs/dev/repositories.md

Repositories

Repositories are the only place database queries are written. One per feature (app/features/<feature>/FeatureRepository.server.ts), imported as a module: import * as VodRepository from "~/features/vods/VodRepository.server".

See database-schemas.md for how columns are typed and database-relations.md for how the tables relate.

Note: plenty of older repositories don't follow this yet. Fix them as you touch them rather than leaving a new style behind.

Files

• One repository per feature. Split into several when a feature owns clearly separate table clusters (TournamentRepository, TournamentTeamRepository, TournamentAuditLogRepository), not merely because a file got long.
• Module names are unique across the whole app. Two SkillRepository files can't both be imported as SkillRepository in the same file.
• Order inside a file: types & constants → read functions → write functions → private helpers at the bottom.

Naming

Reads:

Returns	Name
One row or nothing	findById, findByUserId, findLookingTeamsByTournamentId
An array	findAllByTournamentId, findAllVods
A number	countVods
A boolean	existsByCustomUrl, hasUnvalidatedImages

Writes are named after the SQL verb: insert, update, upsert, deleteById. Not create, del, remove, add.

Rules:

• Name the lookup key: findById when it's the table's own id, otherwise ByUserId, ByTournamentId, ByInviteCode. Bare nouns (userCards, widgetsByUserId) don't say what they do.
• Own means the logged in user's own rows: updateOwnProfile, upsertOwnNote. See "The acting user" below.
• Domain operations that aren't a plain write keep a domain verb (mergeTeams, leaveLfg, finalize). Don't force those into CRUD names.

Arguments

• One value → positional. If it's an id, the name says which: findById(id), findAllByUserId(userId).
• Two or more → a single object literal. Name the type <FunctionName>Args when it's worth extracting.
• trx is always the last positional parameter, never a property of the args object.

export function updateTeamNote({ teamId, value }: { teamId: number; value: string | null }) { … }
export async function addInitialSkill(args: AddInitialSkillArgs, trx?: Transaction<DB>) { … }

Transactions

The repository owns the transaction — actions never open one (if it can be avoided).

• A function that writes to more than one table wraps itself in db.transaction().execute(...).
• A function callers may need to compose into a bigger transaction takes an optional trx:

export async function addInitialSkill(args: AddInitialSkillArgs, trx?: Transaction<DB>) {
	const executor = trx ?? db;
	await executor.insertInto("Skill").values(…).execute();
}

• Private helpers that only ever run inside a transaction take a required trx: Transaction<DB>.

Return values

• A missing row is undefined — what Kysely already gives us. Don't map it to null.
• Return plain data. Never return a Kysely query builder or a raw sql fragment from a repository; shared SQL fragments live in ~/utils/kysely.server.
• Convert at the boundary so callers deal in domain values: take a boolean and write it with toDBBoolean, take a Date and write it with dateToDatabaseTimestamp.
• A write returns the inserted row's id when the row has an id — that is, when other rows can reference it. insert, upsert, addInitialSkill, insertFriendship and friends all .returning("id") (or .returningAll() where the caller wants the row), and a bulk insert returns an array in insertion order. Writes to join and detail tables, keyed by their foreign keys rather than an id of their own (GroupMember, MapPoolMap, PlusVote, AllTeamMember), return nothing — there is no value a caller could use.

Types

Infer as much as possible. A repository's types should follow from the query and the schema, so that changing a column breaks the code that depends on it.

• Never as. No as any, no as unknown as, no asserting a row into the shape you wanted. A cast that seems necessary means the query or the tables.ts typing is wrong — fix that instead.
• $castTo<T>() is the sanctioned exception, and only where Kysely genuinely can't infer: raw sql fragments and json_group_array aggregates. $narrowType<{ x: NotNull }>() for narrowing Kysely knows it can't prove.
• Return types are derived, never written by hand: type Vod = Unwrapped<typeof findAllVods>.
• Insert arguments come from TablesInsertable rather than restating column types:

export function insertFriendCode(args: TablesInsertable["UserFriendCode"]) { … }

// Omit what the repository fills in itself
export function addModNote(args: Omit<TablesInsertable["ModNote"], "authorId">) { … }

// or pick single columns when the args are a mix
type InsertArgs = {
	ownerId: TablesInsertable["Build"]["ownerId"];
	weapons: Array<BuildWeapon>;
};

• Use Tables["Table"]["column"] the same way for read arguments and hand-built row types.

The acting user

actorId() reads the logged in user from request context. Use it when the acting user isn't something the caller gets to choose. There are three such cases:

• The actor's own rows. The operation is by definition about the logged in user. Name it *Own*: updateOwnProfile, deleteOwnNoteById, upsertOwn.
• Attribution. The write records who performed it — authorId, actorUserId, reportedByUserId, canceledByUserId. The function isn't otherwise about the actor, so it keeps its normal name (insert, cancelScrim, addModNote); the JSDoc mentions the column it fills.
• Viewer scoping. A read whose visible rows depend on who's asking uses actorIdOrNull(), since these routes also serve anonymous visitors. The JSDoc says what the actor scopes.

Any user id the caller picks is an explicit parameter — findAllByUserId(userId) must never quietly mean the actor. Code that has to run outside a request (routines, scripts, seeds) can't use actorId() at all, so functions they call take ids explicitly.

What belongs in a repository

• Queries, row mapping, and DB-shape conversion. Nothing else.
• Throw domain errors (LimitReachedError, DuplicateEntryError, ConcurrentModificationError from ~/utils/errors), never an HTTP Response. Mapping to a status code is the action's job.
• Importing core logic is fine when the transformation must be identical everywhere the data is read (e.g. sortBadgesByFavorites, Progression). Decisions that vary per caller belong in the loader/action.
• Repositories may import other repositories, but no cycles.

Query style

• Qualify every column: "Video.id", not "id".
• Reuse the shared selects in ~/utils/kysely.server (commonUserSelect, commonUserJsonObject, commonUserObjectFields) instead of re-listing user fields.
• Prefer jsonArrayFrom / jsonBuildObject from kysely/helpers/sqlite over raw json_group_array. When raw sql is needed, a comment says why.
• Never insert row-by-row in a loop — one values([...]) call.
• Optional filters are applied by reassigning the query:

let query = db.selectFrom("Video").selectAll("Video");
if (mode) {
	query = query.where("VideoMatch.mode", "=", mode);
}

Performance

Writes block the whole server (see architecture.md), and one slow read hurts every route.

• Every list read is bounded — a limit parameter or a key that limits the result set.
• Check EXPLAIN QUERY PLAN for new queries: no unexpected full table scans, indexes actually used.
• Read functions on hot paths get a case in scripts/benchmark-db.ts.

Documentation

Repositories are modules, so exported functions get a JSDoc one-liner saying what they return, plus any scoping that isn't visible from the name ("excludes private builds", "latest row per season"). Non-obvious SQL gets a comment explaining why it's written that way — especially when the obvious form was rejected for performance reasons.

Private helpers can skip the JSDoc or keep it to a line.

Testing

Not every function needs a test. Write one for:

• Transactions touching several tables
• Non-trivial mapping of the returned rows
• Permission, visibility or ownership scoping

Plain findById-style queries don't need one. Tests run against db-test.sqlite3.

A test's setup goes through the factories in app/db/seed/factories, never a raw db.insertInto / db.updateTable — a lint rule enforces this, and seeds.md covers the factories and the rare exceptions. Only the write a test is actually asserting about is called through its repository directly. There is no cleanup to write: the database is wiped after every test that wrote to it.