feat: add type-safety and autocompletion (#8)

src/lib/build.ts

@@ -7,24 +7,25 @@ import type {
 	IncludeQuery,
 	Relation,
 	Relations,
+	Select,
 	SelectQuery,
 	SqlParams,
 	UpdateQuery,
 } from "./types.ts";
 import { connect, formatValue, quoteIdentifier } from "./util";
 import { where } from "./where";
 
-export function buildSelectQuery(
+export function buildSelectQuery<T = unknown, R extends string = "none">(
 	key: string,
-	query: SelectQuery | IncludeQuery,
+	query: SelectQuery<T, R> | IncludeQuery<T, R>,
 	relations: Relations,
 	isNested = false,
 	append?: {
 		where?: string;
 		join?: string;
 	},
 ): string {
-	const columns = {
+	const columns: Select = {
 		...(query.select || {}),
 	};
 	// Directly mutate columns to include all keys from query.include
@@ -36,7 +37,7 @@ export function buildSelectQuery(
 	const args: SqlParams = {
 		select: "",
 		where: query.where,
-		groupBy: query.groupBy,
+		groupBy: query.groupBy as never,
 		having: query.having,
 		orderBy: query.orderBy,
 		limit: query.limit,
@@ -160,31 +161,31 @@ export function buildSelectQuery(
 	return sql(args, append);
 }
 
-export function buildDeleteQuery(
+export function buildDeleteQuery<T = unknown, R extends string = "none">(
 	table: string,
-	query?: DeleteQuery,
+	query?: DeleteQuery<T, R>,
 	relations?: Relations,
 ) {
 	const args: SqlParams = {
 		delete: `DELETE FROM ${quoteIdentifier(table)}`,
 		where: query?.where || {},
-		returning: query?.returning || [],
+		returning: (query?.returning || []) as never,
 		relations: relations,
 		join: "",
 	};
 
 	return sql(args);
 }
 
-export function buildUpdateQuery(
+export function buildUpdateQuery<T = unknown, R extends string = "none">(
 	table: string,
-	query: UpdateQuery,
+	query: UpdateQuery<T, R>,
 	relations?: Relations,
 ) {
 	const args: SqlParams = {
-		update: `UPDATE ${quoteIdentifier(table)} SET ${buildUpdateValues(query.data)}`,
+		update: `UPDATE ${quoteIdentifier(table)} SET ${buildUpdateValues(query.data as never)}`,
 		where: query?.where || {},
-		returning: query?.returning || [],
+		returning: (query?.returning || []) as never,
 		relations: relations,
 	};
 

src/lib/delete.ts

@@ -1,7 +1,13 @@
 import { buildDeleteQuery } from "./build";
 import type { DeleteManyParams } from "./types";
 
-export function deleteMany(params: DeleteManyParams): string {
+export function deleteMany(params: DeleteManyParams): string;
+export function deleteMany<T, R extends string = "none">(
+	params: DeleteManyParams<T, R>,
+): string;
+export function deleteMany<T = unknown, R extends string = "none">(
+	params: DeleteManyParams<T, R>,
+): string {
 	const { table, query = {}, relations = {} } = params;
-	return buildDeleteQuery(table, query, relations);
+	return buildDeleteQuery<T, R>(table, query, relations);
 }

src/lib/find.ts

@@ -1,7 +1,13 @@
 import { buildSelectQuery } from "./build";
 import type { FindManyParams } from "./types";
 
-export function findMany(params: FindManyParams): string {
+export function findMany(params: FindManyParams): string;
+export function findMany<T, R extends string = "none">(
+	params: FindManyParams<T, R>,
+): string;
+export function findMany<T = unknown, R extends string = "none">(
+	params: FindManyParams<T, R>,
+): string {
 	const { table, query, relations = {} } = params;
-	return buildSelectQuery(table, query, relations, false);
+	return buildSelectQuery<T, R>(table, query, relations, false);
 }

src/lib/insert.ts

@@ -2,7 +2,9 @@ import { buildColumns, buildValues } from "./build";
 import type { InsertManyParams, InsertOneParams } from "./types";
 import { quoteIdentifier } from "./util";
 
-export function insertOne(params: InsertOneParams): string {
+export function insertOne(params: InsertOneParams): string;
+export function insertOne<T>(params: InsertOneParams<T>): string;
+export function insertOne<T = unknown>(params: InsertOneParams<T>): string {
 	const { table, data, returning = [] } = params;
 
 	if (!table || table.trim() === "") {
@@ -27,7 +29,9 @@ export function insertOne(params: InsertOneParams): string {
 	)} (${columns}) VALUES (${values})${_returning}`;
 }
 
-export function insertMany(params: InsertManyParams): string {
+export function insertMany(params: InsertManyParams): string;
+export function insertMany<T>(params: InsertManyParams<T>): string;
+export function insertMany<T = unknown>(params: InsertManyParams<T>): string {
 	const { table, data, returning = [] } = params;
 
 	if (!table || table.trim() === "") {
@@ -38,9 +42,9 @@ export function insertMany(params: InsertManyParams): string {
 		throw new Error("Data must be a non-empty array");
 	}
 
-	const columns = buildColumns(Object.keys(data[0]));
+	const columns = buildColumns(Object.keys(data[0] as never));
 	const values = data
-		.map((row) => `(${buildValues(Object.values(row))})`)
+		.map((row) => `(${buildValues(Object.values(row as never))})`)
 		.join(", ");
 	const _returning =
 		returning.length > 0 ? ` RETURNING ${buildColumns(returning)}` : "";