techdebt: create a ReplicationMode type and update function defs

create a type to track ReplicationMode instead of writing out
`"master"|"slave"` everywhere.

update to drop the default from the QueryRunner constructor
as they will always receive the mode from the driver when
it's part of the QueryRunner

also drop the default from Driver.createQueryRunner in the
implementations - the interface mandates the mode to be defined
so it will never be omitted anyway

also drop the explict "master" from any connection.createQueryRunner
calls so we leave it either the default or `slave` when needed

all of this makes it easier to eventually migrate to
other naming convetions for the replication mode
should it be deemed the right path to go down

Author: imnotjames

src/cache/DbQueryResultCache.ts

@@ -229,7 +229,7 @@ export class DbQueryResultCache implements QueryResultCache {
         if (queryRunner)
             return queryRunner;
 
-        return this.connection.createQueryRunner("master");
+        return this.connection.createQueryRunner();
     }
 
 }

src/commands/QueryCommand.ts

@@ -48,7 +48,7 @@ export class QueryCommand implements yargs.CommandModule {
             connection = await createConnection(connectionOptions);
 
             // create a query runner and execute query using it
-            queryRunner = connection.createQueryRunner("master");
+            queryRunner = connection.createQueryRunner();
             console.log(chalk.green("Running query: ") + PlatformTools.highlightSql(args._[1]));
             const queryResult = await queryRunner.query(args._[1]);
             console.log(chalk.green("Query has been executed. Result: "));

src/connection/Connection.ts

@@ -40,6 +40,7 @@ import {PromiseUtils} from "../";
 import {IsolationLevel} from "../driver/types/IsolationLevel";
 import {AuroraDataApiDriver} from "../driver/aurora-data-api/AuroraDataApiDriver";
 import {DriverUtils} from "../driver/DriverUtils";
+import {ReplicationMode} from "../driver/types/ReplicationMode";
 
 /**
  * Connection is a single database ORM connection to a specific database.
@@ -259,7 +260,7 @@ export class Connection {
      */
     // TODO rename
     async dropDatabase(): Promise<void> {
-        const queryRunner = this.createQueryRunner("master");
+        const queryRunner = this.createQueryRunner();
         try {
             if (this.driver instanceof SqlServerDriver || this.driver instanceof MysqlDriver || this.driver instanceof AuroraDataApiDriver) {
                 const databases: string[] = this.driver.database ? [this.driver.database] : [];
@@ -395,7 +396,7 @@ export class Connection {
         if (queryRunner && queryRunner.isReleased)
             throw new QueryRunnerProviderAlreadyReleasedError();
 
-        const usedQueryRunner = queryRunner || this.createQueryRunner("master");
+        const usedQueryRunner = queryRunner || this.createQueryRunner();
 
         try {
             return await usedQueryRunner.query(query, parameters);  // await is needed here because we are using finally
@@ -444,7 +445,7 @@ export class Connection {
      * If you perform writes you must use master database,
      * if you perform reads you can use slave databases.
      */
-    createQueryRunner(mode: "master"|"slave" = "master"): QueryRunner {
+    createQueryRunner(mode: ReplicationMode = "master"): QueryRunner {
         const queryRunner = this.driver.createQueryRunner(mode);
         const manager = this.createEntityManager(queryRunner);
         Object.assign(queryRunner, { manager: manager });

src/driver/Driver.ts

@@ -8,6 +8,7 @@ import {DataTypeDefaults} from "./types/DataTypeDefaults";
 import {BaseConnectionOptions} from "../connection/BaseConnectionOptions";
 import {TableColumn} from "../schema-builder/table/TableColumn";
 import {EntityMetadata} from "../metadata/EntityMetadata";
+import {ReplicationMode} from "./types/ReplicationMode";
 
 /**
  * Driver organizes TypeORM communication with specific database management system.
@@ -102,7 +103,7 @@ export interface Driver {
     /**
      * Creates a query runner used for common queries.
      */
-    createQueryRunner(mode: "master"|"slave"): QueryRunner;
+    createQueryRunner(mode: ReplicationMode): QueryRunner;
 
     /**
      * Replaces parameters in the given sql with special escaping character

src/driver/aurora-data-api-pg/AuroraDataApiPostgresQueryRunner.ts

@@ -5,11 +5,12 @@ import {QueryRunner} from "../../query-runner/QueryRunner";
 import {IsolationLevel} from "../types/IsolationLevel";
 import {AuroraDataApiPostgresDriver} from "../postgres/PostgresDriver";
 import {PostgresQueryRunner} from "../postgres/PostgresQueryRunner";
+import {ReplicationMode} from "../types/ReplicationMode";
 
 class PostgresQueryRunnerWrapper extends PostgresQueryRunner {
     driver: any;
 
-    constructor(driver: any, mode: "master"|"slave") {
+    constructor(driver: any, mode: ReplicationMode) {
         super(driver, mode);
     }
 }
@@ -46,7 +47,7 @@ export class AuroraDataApiPostgresQueryRunner extends PostgresQueryRunnerWrapper
     // Constructor
     // -------------------------------------------------------------------------
 
-    constructor(driver: AuroraDataApiPostgresDriver, mode: "master"|"slave" = "master") {
+    constructor(driver: AuroraDataApiPostgresDriver, mode: ReplicationMode) {
         super(driver, mode);
     }
 

src/driver/aurora-data-api/AuroraDataApiConnection.ts

@@ -1,6 +1,7 @@
 import {AuroraDataApiQueryRunner} from "./AuroraDataApiQueryRunner";
 import {Connection} from "../../connection/Connection";
 import {ConnectionOptions, QueryRunner} from "../..";
+import {ReplicationMode} from "../types/ReplicationMode";
 
 /**
  * Organizes communication with MySQL DBMS.
@@ -13,7 +14,7 @@ export class AuroraDataApiConnection extends Connection {
         this.queryRunnter = queryRunner;
     }
 
-    public createQueryRunner(mode: "master" | "slave" = "master"): QueryRunner {
+    public createQueryRunner(mode: ReplicationMode): QueryRunner {
         return this.queryRunnter;
     }
 

src/driver/aurora-data-api/AuroraDataApiDriver.ts

@@ -16,6 +16,7 @@ import {AuroraDataApiConnectionCredentialsOptions} from "./AuroraDataApiConnecti
 import {EntityMetadata} from "../../metadata/EntityMetadata";
 import {OrmUtils} from "../../util/OrmUtils";
 import {ApplyValueTransformers} from "../../util/ApplyValueTransformers";
+import {ReplicationMode} from "../types/ReplicationMode";
 
 /**
  * Organizes communication with MySQL DBMS.
@@ -355,7 +356,7 @@ export class AuroraDataApiDriver implements Driver {
     /**
      * Creates a query runner used to execute database queries.
      */
-    createQueryRunner(mode: "master"|"slave" = "master") {
+    createQueryRunner(mode: ReplicationMode) {
         return new AuroraDataApiQueryRunner(this);
     }
 

src/driver/better-sqlite3/BetterSqlite3Driver.ts

@@ -9,6 +9,7 @@ import { QueryRunner } from "../../query-runner/QueryRunner";
 import { AbstractSqliteDriver } from "../sqlite-abstract/AbstractSqliteDriver";
 import { BetterSqlite3ConnectionOptions } from "./BetterSqlite3ConnectionOptions";
 import { BetterSqlite3QueryRunner } from "./BetterSqlite3QueryRunner";
+import {ReplicationMode} from "../types/ReplicationMode";
 
 /**
  * Organizes communication with sqlite DBMS.
@@ -63,7 +64,7 @@ export class BetterSqlite3Driver extends AbstractSqliteDriver {
     /**
      * Creates a query runner used to execute database queries.
      */
-    createQueryRunner(mode: "master" | "slave" = "master"): QueryRunner {
+    createQueryRunner(mode: ReplicationMode): QueryRunner {
         if (!this.queryRunner)
             this.queryRunner = new BetterSqlite3QueryRunner(this);
 

src/driver/cockroachdb/CockroachDriver.ts

@@ -19,6 +19,7 @@ import {EntityMetadata} from "../../metadata/EntityMetadata";
 import {OrmUtils} from "../../util/OrmUtils";
 import {CockroachQueryRunner} from "./CockroachQueryRunner";
 import {ApplyValueTransformers} from "../../util/ApplyValueTransformers";
+import {ReplicationMode} from "../types/ReplicationMode";
 
 /**
  * Organizes communication with Cockroach DBMS.
@@ -284,7 +285,7 @@ export class CockroachDriver implements Driver {
     /**
      * Creates a query runner used to execute database queries.
      */
-    createQueryRunner(mode: "master"|"slave" = "master") {
+    createQueryRunner(mode: ReplicationMode) {
         return new CockroachQueryRunner(this, mode);
     }
 

src/driver/cockroachdb/CockroachQueryRunner.ts

@@ -22,6 +22,7 @@ import {TableCheck} from "../../schema-builder/table/TableCheck";
 import {ColumnType} from "../../index";
 import {IsolationLevel} from "../types/IsolationLevel";
 import {TableExclusion} from "../../schema-builder/table/TableExclusion";
+import {ReplicationMode} from "../types/ReplicationMode";
 
 /**
  * Runs queries on a single postgres database connection.
@@ -65,7 +66,7 @@ export class CockroachQueryRunner extends BaseQueryRunner implements QueryRunner
     // Constructor
     // -------------------------------------------------------------------------
 
-    constructor(driver: CockroachDriver, mode: "master"|"slave" = "master") {
+    constructor(driver: CockroachDriver, mode: ReplicationMode) {
         super();
         this.driver = driver;
         this.connection = driver.connection;