Refactor for fuction that checks if db is system db

extensions/mssql/src/constants/constants.ts

@@ -161,6 +161,7 @@ export const defaultPortNumber = 1433;
 export const integratedauth = "Integrated";
 export const sqlAuthentication = "SqlLogin";
 export const defaultDatabase = "master";
+export const systemDatabases = ["master", "tempdb", "model", "msdb"];
 export const defaultSchema = "dbo";
 export const errorPasswordExpired = 18487;
 export const errorPasswordNeedsReset = 18488;

extensions/mssql/src/profiler/profilerController.ts

@@ -24,12 +24,10 @@ import { ObjectExplorerUtils } from "../objectExplorer/objectExplorerUtils";
 import { IConnectionProfile } from "../models/interfaces";
 import { getServerTypes, isAzureSqlDbCompatible } from "../models/connectionInfo";
 import { getErrorMessage, uuid } from "../utils/utils";
+import { isSystemDatabase } from "../utils/databaseUtils";
 import { sendActionEvent, sendErrorEvent } from "../telemetry/telemetry";
 import { TelemetryViews, TelemetryActions } from "../sharedInterfaces/telemetry";
 
-/** System databases that cannot be used for Azure SQL profiling */
-const SYSTEM_DATABASES = ["master", "tempdb", "model", "msdb"];
-
 /**
  * Controller for the profiler feature.
  * Handles command registration, connection management, and launching the profiler UI.
@@ -116,7 +114,7 @@ export class ProfilerController {
                 // connects at server level; otherwise the STS may look for the session
                 // in the database scope and fail with "session not found".
                 // Preserve the database as a client-side filter if one isn't already set.
-                if (profileToUse.database && !this.isSystemDatabase(profileToUse.database)) {
+                if (profileToUse.database && !isSystemDatabase(profileToUse.database)) {
                     if (!databaseScopeFilter) {
                         databaseScopeFilter = profileToUse.database;
                     }
@@ -173,18 +171,6 @@ export class ProfilerController {
     // Private Methods
     // ============================================================
 
-    /**
-     * Checks if a database is a system database.
-     * @param databaseName - The name of the database to check
-     * @returns true if the database is a system database
-     */
-    private isSystemDatabase(databaseName: string | undefined): boolean {
-        if (!databaseName) {
-            return true; // No database selected is treated as system database for this purpose
-        }
-        return SYSTEM_DATABASES.includes(databaseName.toLowerCase());
-    }
-
     /**
      * Ensures a user database is selected for Azure SQL connections.
      * If no database or a system database is selected, prompts the user to select one.
@@ -195,7 +181,7 @@ export class ProfilerController {
         connectionProfile: IConnectionProfile,
     ): Promise<IConnectionProfile | undefined> {
         // Check if a user database is already selected
-        if (!this.isSystemDatabase(connectionProfile.database)) {
+        if (!isSystemDatabase(connectionProfile.database)) {
             this._logger.verbose(`User database already selected: ${connectionProfile.database}`);
             return connectionProfile;
         }
@@ -218,7 +204,7 @@ export class ProfilerController {
             const databases = await this._connectionManager.listDatabases(tempUri);
 
             // Filter out system databases
-            const userDatabases = databases.filter((db) => !this.isSystemDatabase(db));
+            const userDatabases = databases.filter((db) => !isSystemDatabase(db));
 
             if (userDatabases.length === 0) {
                 this._logger.verbose("No user databases found");

extensions/mssql/src/utils/databaseUtils.ts

@@ -0,0 +1,20 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { systemDatabases } from "../constants/constants";
+
+/**
+ * Checks whether a database name refers to a system database (or is empty/undefined).
+ * The check is case-insensitive.
+ *
+ * @param databaseName - The database name to check
+ * @returns `true` if the name is undefined, empty, or matches a system database
+ */
+export function isSystemDatabase(databaseName: string | undefined): boolean {
+    if (!databaseName) {
+        return true;
+    }
+    return systemDatabases.includes(databaseName.toLowerCase());
+}

extensions/mssql/test/unit/profiler/profilerController.test.ts

@@ -701,6 +701,7 @@ suite("ProfilerController Server Type Tests", () => {
             },
         };
 
+        connectionManager.listDatabases.resolves(["master", "tempdb", "UserDB1"]);
         showQuickPickStub.resolves("UserDB1");
 
         createController();
@@ -720,6 +721,7 @@ suite("ProfilerController Server Type Tests", () => {
             },
         };
 
+        connectionManager.listDatabases.resolves(["master", "tempdb", "UserDB1"]);
         showQuickPickStub.resolves("UserDB1");
 
         createController();
@@ -811,6 +813,7 @@ suite("ProfilerController Server Type Tests", () => {
             },
         };
 
+        // User cancels database selection via quick pick
         showQuickPickStub.resolves(undefined); // User cancelled
 
         createController();
@@ -831,7 +834,7 @@ suite("ProfilerController Server Type Tests", () => {
             },
         };
 
-        // First connect call (for temp connection to get database list) fails
+        // The temp connection for listing databases fails
         connectionManager.connect.resolves(false);
 
         const showErrorMessageStub = vscode.window.showErrorMessage as sinon.SinonStub;

extensions/mssql/test/unit/utils/databaseUtils.test.ts

@@ -0,0 +1,48 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { expect } from "chai";
+import * as chai from "chai";
+import sinonChai from "sinon-chai";
+import { isSystemDatabase } from "../../../src/utils/databaseUtils";
+import { systemDatabases } from "../../../src/constants/constants";
+
+chai.use(sinonChai);
+
+suite("databaseUtils", () => {
+    suite("systemDatabases", () => {
+        test("should contain the four well-known system databases", () => {
+            expect(systemDatabases).to.include.members(["master", "tempdb", "model", "msdb"]);
+            expect(systemDatabases).to.have.lengthOf(4);
+        });
+    });
+
+    suite("isSystemDatabase", () => {
+        test("should return true for undefined", () => {
+            expect(isSystemDatabase(undefined)).to.be.true;
+        });
+
+        test("should return true for empty string", () => {
+            expect(isSystemDatabase("")).to.be.true;
+        });
+
+        test("should return true for each system database", () => {
+            for (const db of systemDatabases) {
+                expect(isSystemDatabase(db)).to.be.true;
+            }
+        });
+
+        test("should be case-insensitive", () => {
+            expect(isSystemDatabase("MASTER")).to.be.true;
+            expect(isSystemDatabase("Master")).to.be.true;
+            expect(isSystemDatabase("TempDb")).to.be.true;
+        });
+
+        test("should return false for user databases", () => {
+            expect(isSystemDatabase("MyAppDb")).to.be.false;
+            expect(isSystemDatabase("AdventureWorks")).to.be.false;
+        });
+    });
+});