Moved Oracle DB types mapping to the OracleSingleton class (#51)

* moved the oracle db types mapping to the OracleSingleton class

* check if map is empty

* correctly check if map is empty

* more concised, getter and root scope cleanedup

* typo

Author: Sylvestre

lib/oracle.js

@@ -6,22 +6,71 @@ import {badRequest, failedCheck} from "./errors.js";
 import {validateQueryPayload} from "./validate.js";
 
 const READ_ONLY = new Set(["SELECT", "USAGE", "CONNECT"]);
-
 export class OracleSingleton {
   static instance = null;
+  static types = new Map();
   constructor() {
     throw new Error(
       "Do not use new OracleSingleton(). Call OracleSingleton.initialize() instead."
     );
   }
   static initialize() {
+    const boolean = ["null", "boolean"],
+      number = ["null", "number"],
+      object = ["null", "object"],
+      string = ["null", "string"];
+
     if (!OracleSingleton.instance) {
       try {
         OracleSingleton.instance = import("oracledb").then((module) => {
           const oracledb = module.default;
           oracledb.initOracleClient({
             libDir: process.env.LIB_DIR_PATH,
           });
+
+          OracleSingleton.types
+            .set(oracledb.DB_TYPE_BOOLEAN, {
+              type: boolean,
+            })
+            .set(oracledb.DB_TYPE_NUMBER, {type: number})
+            .set(oracledb.DB_TYPE_BINARY_FLOAT, {
+              type: number,
+            })
+            .set(oracledb.DB_TYPE_BINARY_DOUBLE, {
+              type: number,
+            })
+            .set(oracledb.DB_TYPE_BINARY_INTEGER, {
+              type: number,
+            })
+            .set(oracledb.DB_TYPE_TIMESTAMP, {
+              type: string,
+              date: true,
+            })
+            .set(oracledb.DB_TYPE_DATE, {
+              type: string,
+              date: true,
+            })
+            .set(oracledb.DB_TYPE_TIMESTAMP_TZ, {
+              type: string,
+              date: true,
+            })
+            .set(oracledb.DB_TYPE_TIMESTAMP_LTZ, {
+              type: string,
+              date: true,
+            })
+            .set(oracledb.DB_TYPE_INTERVAL_DS, {
+              type: string,
+              date: true,
+            })
+            .set(oracledb.DB_TYPE_INTERVAL_YM, {
+              type: string,
+              date: true,
+            })
+            .set(oracledb.DB_TYPE_BLOB, {
+              type: object,
+              buffer: true,
+            });
+
           return oracledb;
         });
       } catch (err) {
@@ -36,6 +85,14 @@ export class OracleSingleton {
       );
     return OracleSingleton.instance;
   }
+
+  get types() {
+    if (OracleSingleton.types.size === 0)
+      throw new Error(
+        "OracleSingleton not initialized. Call OracleSingleton.initialize() first."
+      );
+    return OracleSingleton.types;
+  }
 }
 
 export async function queryStream(req, res, pool) {
@@ -179,43 +236,11 @@ export default async ({url, username, password}) => {
 };
 
 // See https://oracle.github.io/node-oracledb/doc/api.html#-312-oracle-database-type-constants
-const boolean = ["null", "boolean"],
-  number = ["null", "number"],
-  object = ["null", "object"],
-  string = ["null", "string"];
-export function dataTypeSchema({type}) {
-  const oracledb = OracleSingleton.getInstance();
-
-  switch (type) {
-    case oracledb.DB_TYPE_BOOLEAN:
-      return {type: boolean};
-    case oracledb.DB_TYPE_NUMBER:
-    case oracledb.DB_TYPE_BINARY_DOUBLE:
-    case oracledb.DB_TYPE_BINARY_FLOAT:
-    case oracledb.DB_TYPE_BINARY_INTEGER:
-      return {type: number};
-    case oracledb.DB_TYPE_TIMESTAMP:
-    case oracledb.DB_TYPE_DATE:
-    case oracledb.DB_TYPE_TIMESTAMP_TZ:
-    case oracledb.DB_TYPE_TIMESTAMP_LTZ:
-    case oracledb.DB_TYPE_INTERVAL_DS:
-    case oracledb.DB_TYPE_INTERVAL_YM:
-      return {type: string, date: true};
-    case oracledb.DB_TYPE_BLOB:
-      return {type: object, buffer: true};
-    case oracledb.DB_TYPE_CHAR:
-    case oracledb.DB_TYPE_BFILE:
-    case oracledb.DB_TYPE_CLOB:
-    case oracledb.DB_TYPE_NCLOB:
-    case oracledb.DB_TYPE_CURSOR:
-    case oracledb.DB_TYPE_LONG_RAW:
-    case oracledb.DB_TYPE_NCHAR:
-    case oracledb.DB_TYPE_NVARCHAR:
-    case oracledb.DB_TYPE_OBJECT:
-    case oracledb.DB_TYPE_RAW:
-    case oracledb.DB_TYPE_ROWID:
-    case oracledb.DB_TYPE_VARCHAR:
-    default:
-      return {type: string};
+function dataTypeSchema({type}) {
+  const types = OracleSingleton.types;
+  if (types.has(type)) {
+    return types.get(type);
   }
+
+  return {type: ["null", "string"]};
 }