perf: don't recompile escapeRegExp for every query (typeorm#8956)

Context: the query builder is pretty CPU intensive, and can be slow -
e.g. typeorm#3857

One of the things which makes this slow is `escapeRegExp` in the query
builder: we freshly construct the same RegExp once per
`replacePropertyName` invocation (many times per overall query!) and
since the RegExp itself is constant -- we can lift it out and construct
it once.

Over-all this saves about 8% on our query build times as measured by
 typeorm#8955.

src/query-builder/QueryBuilder.ts

@@ -1,28 +1,30 @@
-import {ObjectLiteral} from "../common/ObjectLiteral";
-import {QueryRunner} from "../query-runner/QueryRunner";
-import {Connection} from "../connection/Connection";
-import {QueryExpressionMap} from "./QueryExpressionMap";
-import {SelectQueryBuilder} from "./SelectQueryBuilder";
-import {UpdateQueryBuilder} from "./UpdateQueryBuilder";
-import {DeleteQueryBuilder} from "./DeleteQueryBuilder";
-import {SoftDeleteQueryBuilder} from "./SoftDeleteQueryBuilder";
-import {InsertQueryBuilder} from "./InsertQueryBuilder";
-import {RelationQueryBuilder} from "./RelationQueryBuilder";
-import {EntityTarget} from "../common/EntityTarget";
-import {Alias} from "./Alias";
-import {Brackets} from "./Brackets";
-import {QueryDeepPartialEntity} from "./QueryPartialEntity";
-import {EntityMetadata} from "../metadata/EntityMetadata";
-import {ColumnMetadata} from "../metadata/ColumnMetadata";
-import {SqljsDriver} from "../driver/sqljs/SqljsDriver";
-import {PostgresDriver} from "../driver/postgres/PostgresDriver";
-import {CockroachDriver} from "../driver/cockroachdb/CockroachDriver";
-import {SqlServerDriver} from "../driver/sqlserver/SqlServerDriver";
-import {OracleDriver} from "../driver/oracle/OracleDriver";
-import {EntitySchema} from "../";
-import {FindOperator} from "../find-options/FindOperator";
-import {In} from "../find-options/operator/In";
-import {EntityColumnNotFound} from "../error/EntityColumnNotFound";
+import { ObjectLiteral } from "../common/ObjectLiteral"
+import { QueryRunner } from "../query-runner/QueryRunner"
+import { DataSource } from "../data-source/DataSource"
+import { QueryBuilderCteOptions } from "./QueryBuilderCte"
+import { QueryExpressionMap } from "./QueryExpressionMap"
+import { SelectQueryBuilder } from "./SelectQueryBuilder"
+import { UpdateQueryBuilder } from "./UpdateQueryBuilder"
+import { DeleteQueryBuilder } from "./DeleteQueryBuilder"
+import { SoftDeleteQueryBuilder } from "./SoftDeleteQueryBuilder"
+import { InsertQueryBuilder } from "./InsertQueryBuilder"
+import { RelationQueryBuilder } from "./RelationQueryBuilder"
+import { EntityTarget } from "../common/EntityTarget"
+import { Alias } from "./Alias"
+import { Brackets } from "./Brackets"
+import { QueryDeepPartialEntity } from "./QueryPartialEntity"
+import { EntityMetadata } from "../metadata/EntityMetadata"
+import { ColumnMetadata } from "../metadata/ColumnMetadata"
+import { FindOperator } from "../find-options/FindOperator"
+import { In } from "../find-options/operator/In"
+import { TypeORMError } from "../error"
+import { WhereClause, WhereClauseCondition } from "./WhereClause"
+import { NotBrackets } from "./NotBrackets"
+import { EntityPropertyNotFoundError } from "../error/EntityPropertyNotFoundError"
+import { ReturningType } from "../driver/Driver"
+import { OracleDriver } from "../driver/oracle/OracleDriver"
+import { InstanceChecker } from "../util/InstanceChecker"
+import { escapeRegExp } from "../util/escapeRegExp"
 
 // todo: completely cover query builder with tests
 // todo: entityOrProperty can be target name. implement proper behaviour if it is.
@@ -576,10 +578,6 @@ export abstract class QueryBuilder<Entity> {
      * Replaces all entity's propertyName to name in the given statement.
      */
     protected replacePropertyNames(statement: string) {
-        // Escape special characters in regular expressions
-        // Per https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Escaping
-        const escapeRegExp = (s: String) => s.replace(/[.*+\-?^${}()|[\]\\]/g, "\\$&");
-
         for (const alias of this.expressionMap.aliases) {
             if (!alias.hasMetadata) continue;
             const replaceAliasNamePrefix = this.expressionMap.aliasNamePrefixingEnabled ? `${alias.name}.` : "";

src/util/escapeRegExp.ts

@@ -0,0 +1,4 @@
+// Escape special characters in regular expressions
+// Per https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Escaping
+const ESCAPE_REGEXP = /[.*+\-?^${}()|[\]\\]/g
+export const escapeRegExp = (s: String) => s.replace(ESCAPE_REGEXP, "\\$&")