Import other modules into monorepo

src/orm/connection/Connection.ts

@@ -0,0 +1,65 @@
+import {Collection, ErrorWithContext} from "../../util";
+import {QueryResult} from "../types";
+import {SQLDialect} from "../dialect/SQLDialect";
+import {AppClass} from "../../lifecycle/AppClass";
+
+/**
+ * Error thrown when a connection is used before it is ready.
+ * @extends Error
+ */
+export class ConnectionNotReadyError extends ErrorWithContext {
+    constructor(name = '', context: {[key: string]: any} = {}) {
+        super(`The connection ${name} is not ready and cannot execute queries.`)
+        this.context = context
+    }
+}
+
+/**
+ * Abstract base class for database connections.
+ * @abstract
+ */
+export abstract class Connection extends AppClass {
+
+    constructor(
+        /**
+         * The name of this connection
+         * @type string
+         */
+        public readonly name: string,
+        /**
+         * This connection's config object
+         */
+        public readonly config: any = {},
+    ) { super() }
+
+    public abstract dialect(): SQLDialect
+
+    /**
+     * Open the connection.
+     * @return Promise<void>
+     */
+    public abstract init(): Promise<void>
+
+    /**
+     * Execute an SQL query and get the result.
+     * @param {string} query
+     * @return Promise<QueryResult>
+     */
+    public abstract query(query: string): Promise<QueryResult>
+
+    /**
+     * Close the connection.
+     * @return Promise<void>
+     */
+    public abstract close(): Promise<void>
+
+    // public abstract databases(): Promise<Collection<Database>>
+
+    // public abstract database(name: string): Promise<Database | undefined>
+
+    // public abstract database_as_schema(name: string): Promise<Database>
+
+    // public abstract tables(database_name: string): Promise<Collection<Table>>
+
+    // public abstract table(database_name: string, table_name: string): Promise<Table | undefined>
+}

src/orm/connection/PostgresConnection.ts

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+import {Connection, ConnectionNotReadyError} from "./Connection";
+import {Client} from "pg";
+import {Inject} from "../../di";
+import {QueryResult} from "../types";
+import {collect} from "../../util";
+import {SQLDialect} from "../dialect/SQLDialect";
+import {PostgreSQLDialect} from "../dialect/PostgreSQLDialect";
+import {Logging} from "../../service/Logging";
+
+/**
+ * Type interface representing the config for a PostgreSQL connection.
+ */
+export interface PostgresConnectionConfig {
+    user: string,
+    host: string,
+    database: string,
+    password?: string,
+    port?: string,
+}
+
+/**
+ * An implementation of a database Connection for dealing with PostgreSQL servers.
+ */
+export class PostgresConnection extends Connection {
+    @Inject()
+    protected readonly logging!: Logging
+
+    /** The `pg` database client. */
+    protected client?: Client
+
+    public dialect(): SQLDialect {
+        return <PostgreSQLDialect> this.app().make(PostgreSQLDialect)
+    }
+
+    public async init() {
+        this.logging.debug(`Initializing PostgreSQL connection ${this.name}...`)
+        this.client = new Client(this.config)
+        await this.client.connect()
+    }
+
+    public async close() {
+        this.logging.debug(`Closing PostgreSQL connection ${this.name}...`)
+        if ( this.client ) {
+            await this.client.end()
+        }
+    }
+
+    public async query(query: string): Promise<QueryResult> {
+        if ( !this.client ) throw new ConnectionNotReadyError(this.name, { config: JSON.stringify(this.config) })
+        this.logging.verbose(`Executing query in connection ${this.name}: \n${query.split('\n').map(x => '    ' + x).join('\n')}`)
+
+        try {
+            const result = await this.client.query(query)
+
+            return {
+                rows: collect(result.rows),
+                rowCount: result.rowCount,
+            }
+        } catch (e) {
+            throw this.app().errorWrapContext(e, {
+                query,
+                connection: this.name,
+            })
+        }
+    }
+}