fix: make tests work with changed vscode clipboard object VSCODE-241 (#271)

We can’t modify a frozen object, which `vscode.env.clipboard` has
recently become.

Refs: microsoft/vscode@4cfd5f8#diff-635fc88732ee6c5c620c7b69dc4b9a56ba478d96505aec360fce3d6fa6b8c314

Author: addaleax

src/test/suite/mdbExtensionController.test.ts

@@ -250,7 +250,7 @@ suite('MDBExtensionController Test Suite', function () {
     );
 
     const mockCopyToClipboard: any = sinon.fake();
-    sinon.replace(vscode.env.clipboard, 'writeText', mockCopyToClipboard);
+    sinon.replaceGetter(vscode.env, 'clipboard', () => ({ writeText: mockCopyToClipboard, readText: sinon.fake() as any }));
 
     const mockStubUri: any = sinon.fake.returns('weStubThisUri');
     sinon.replace(
@@ -284,7 +284,7 @@ suite('MDBExtensionController Test Suite', function () {
     );
 
     const mockCopyToClipboard: any = sinon.fake();
-    sinon.replace(vscode.env.clipboard, 'writeText', mockCopyToClipboard);
+    sinon.replaceGetter(vscode.env, 'clipboard', () => ({ writeText: mockCopyToClipboard, readText: sinon.fake() as any }));
 
     vscode.commands
       .executeCommand('mdb.copyDatabaseName', mockTreeItem)
@@ -315,7 +315,7 @@ suite('MDBExtensionController Test Suite', function () {
     );
 
     const mockCopyToClipboard: any = sinon.fake();
-    sinon.replace(vscode.env.clipboard, 'writeText', mockCopyToClipboard);
+    sinon.replaceGetter(vscode.env, 'clipboard', () => ({ writeText: mockCopyToClipboard, readText: sinon.fake() as any }));
 
     vscode.commands
       .executeCommand('mdb.copyCollectionName', mockTreeItem)
@@ -345,7 +345,7 @@ suite('MDBExtensionController Test Suite', function () {
     );
 
     const mockCopyToClipboard: any = sinon.fake();
-    sinon.replace(vscode.env.clipboard, 'writeText', mockCopyToClipboard);
+    sinon.replaceGetter(vscode.env, 'clipboard', () => ({ writeText: mockCopyToClipboard, readText: sinon.fake() as any }));
 
     const commandResult = await vscode.commands.executeCommand(
       'mdb.copySchemaFieldName',