diff --git a/packages/dockview-core/jest.config.ts b/packages/dockview-core/jest.config.ts
index e047e27b2..d5aa1ca7f 100644
--- a/packages/dockview-core/jest.config.ts
+++ b/packages/dockview-core/jest.config.ts
@@ -20,6 +20,14 @@ const config: JestConfigWithTsJest = {
     coverageDirectory: '<rootDir>/packages/dockview-core/coverage/',
     testResultsProcessor: 'jest-sonar-reporter',
     testEnvironment: 'jsdom',
+    transform: {
+        '^.+\\.tsx?$': [
+            'ts-jest',
+            {
+                tsconfig: '<rootDir>/tsconfig.test.json',
+            },
+        ],
+    },
 };
 
 export default config;
diff --git a/packages/dockview-core/src/__tests__/dockview/dockviewPanelModel.spec.ts b/packages/dockview-core/src/__tests__/dockview/dockviewPanelModel.spec.ts
index b1cf604b0..aacf0ca93 100644
--- a/packages/dockview-core/src/__tests__/dockview/dockviewPanelModel.spec.ts
+++ b/packages/dockview-core/src/__tests__/dockview/dockviewPanelModel.spec.ts
@@ -4,27 +4,39 @@ import {
 } from '../../dockview/dockviewComponent';
 import { DockviewPanelModel } from '../../dockview/dockviewPanelModel';
 import { IContentRenderer, ITabRenderer } from '../../dockview/types';
+import { GroupPanelFrameworkComponentFactory } from '../../dockview/options';
+import { DefaultTab } from '../../dockview/components/tab/defaultTab';
 
 describe('dockviewGroupPanel', () => {
-    test('that dispose is called on content and tab renderers when present', () => {
-        const contentMock = jest.fn<IContentRenderer, []>(() => {
+    let contentMock: jest.Mock<IContentRenderer>;
+    let tabMock: jest.Mock<ITabRenderer>;
+    let accessorMock: jest.Mock<IDockviewComponent>;
+
+    beforeEach(() => {
+        contentMock = jest.fn<IContentRenderer, []>(() => {
             const partial: Partial<IContentRenderer> = {
                 element: document.createElement('div'),
                 dispose: jest.fn(),
+                update: jest.fn(),
+                onGroupChange: jest.fn(),
+                onPanelVisibleChange: jest.fn(),
             };
             return partial as IContentRenderer;
         });
 
-        const tabMock = jest.fn<ITabRenderer, []>(() => {
+        tabMock = jest.fn<ITabRenderer, []>(() => {
             const partial: Partial<IContentRenderer> = {
                 element: document.createElement('div'),
                 dispose: jest.fn(),
+                update: jest.fn(),
+                onGroupChange: jest.fn(),
+                onPanelVisibleChange: jest.fn(),
             };
             return partial as IContentRenderer;
         });
 
-        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
-            return {
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
                 options: {
                     components: {
                         contentComponent: contentMock,
@@ -34,8 +46,12 @@ describe('dockviewGroupPanel', () => {
                     },
                 },
             };
-        });
 
+            return partial as DockviewComponent;
+        });
+    });
+
+    test('that dispose is called on content and tab renderers when present', () => {
         const cut = new DockviewPanelModel(
             <IDockviewComponent>new accessorMock(),
             'id',
@@ -50,34 +66,6 @@ describe('dockviewGroupPanel', () => {
     });
 
     test('that update is called on content and tab renderers when present', () => {
-        const contentMock = jest.fn<IContentRenderer, []>(() => {
-            const partial: Partial<IContentRenderer> = {
-                element: document.createElement('div'),
-                update: jest.fn(),
-            };
-            return partial as IContentRenderer;
-        });
-
-        const tabMock = jest.fn<ITabRenderer, []>(() => {
-            const partial: Partial<IContentRenderer> = {
-                element: document.createElement('div'),
-                update: jest.fn(),
-            };
-            return partial as IContentRenderer;
-        });
-
-        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
-            return {
-                options: {
-                    components: {
-                        contentComponent: contentMock,
-                    },
-                    tabComponents: {
-                        tabComponent: tabMock,
-                    },
-                },
-            };
-        });
         const cut = new DockviewPanelModel(
             <IDockviewComponent>new accessorMock(),
             'id',
@@ -94,36 +82,6 @@ describe('dockviewGroupPanel', () => {
     });
 
     test('that events are fired', () => {
-        const contentMock = jest.fn<IContentRenderer, []>(() => {
-            const partial: Partial<IContentRenderer> = {
-                element: document.createElement('div'),
-                onGroupChange: jest.fn(),
-                onPanelVisibleChange: jest.fn(),
-            };
-            return partial as IContentRenderer;
-        });
-
-        const tabMock = jest.fn<ITabRenderer, []>(() => {
-            const partial: Partial<IContentRenderer> = {
-                element: document.createElement('div'),
-                onGroupChange: jest.fn(),
-                onPanelVisibleChange: jest.fn(),
-            };
-            return partial as IContentRenderer;
-        });
-
-        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
-            return {
-                options: {
-                    components: {
-                        contentComponent: contentMock,
-                    },
-                    tabComponents: {
-                        tabComponent: tabMock,
-                    },
-                },
-            };
-        });
         const cut = new DockviewPanelModel(
             <IDockviewComponent>new accessorMock(),
             'id',
@@ -168,4 +126,176 @@ describe('dockviewGroupPanel', () => {
         expect(cut.content.onPanelVisibleChange).toHaveBeenCalledTimes(2);
         expect(cut.tab.onPanelVisibleChange).toHaveBeenCalledTimes(2);
     });
+
+    test('that the default tab is created', () => {
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
+                options: {
+                    components: {
+                        contentComponent: contentMock,
+                    },
+                    tabComponents: {
+                        tabComponent: jest
+                            .fn()
+                            .mockImplementation(() => tabMock),
+                    },
+                },
+            };
+
+            return partial as DockviewComponent;
+        });
+
+        const cut = new DockviewPanelModel(
+            <IDockviewComponent>new accessorMock(),
+            'id',
+            'contentComponent',
+            'tabComponent'
+        );
+
+        expect(cut.tab).toEqual(tabMock);
+    });
+
+    test('that the provided default tab is chosen when no implementation is provided', () => {
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
+                options: {
+                    components: {
+                        contentComponent: contentMock,
+                    },
+                    tabComponents: {
+                        tabComponent: jest
+                            .fn()
+                            .mockImplementation(() => tabMock),
+                    },
+                    defaultTabComponent: 'tabComponent',
+                },
+            };
+
+            return partial as DockviewComponent;
+        });
+
+        const cut = new DockviewPanelModel(
+            <IDockviewComponent>new accessorMock(),
+            'id',
+            'contentComponent'
+        );
+
+        expect(cut.tab).toEqual(tabMock);
+    });
+
+    test('that the framework tab is created when provided tab is a framework tab', () => {
+        const tab = jest.fn();
+        const tabFactory = jest.fn().mockImplementation(() => tab);
+
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
+                options: {
+                    components: {
+                        contentComponent: contentMock,
+                    },
+                    frameworkTabComponents: {
+                        tabComponent: tabMock,
+                    },
+                    frameworkComponentFactory: (<
+                        Partial<GroupPanelFrameworkComponentFactory>
+                    >{
+                        tab: { createComponent: tabFactory },
+                    }) as GroupPanelFrameworkComponentFactory,
+                },
+            };
+
+            return partial as DockviewComponent;
+        });
+
+        const cut = new DockviewPanelModel(
+            <IDockviewComponent>new accessorMock(),
+            'id',
+            'contentComponent',
+            'tabComponent'
+        );
+
+        expect(tabFactory).toHaveBeenCalledWith('id', 'tabComponent', tabMock);
+        expect(cut.tab).toEqual(tab);
+    });
+
+    test('that is library default tab instance is created when no alternative exists', () => {
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
+                options: {
+                    components: {
+                        contentComponent: contentMock,
+                    },
+                },
+            };
+
+            return partial as DockviewComponent;
+        });
+
+        const cut = new DockviewPanelModel(
+            <IDockviewComponent>new accessorMock(),
+            'id',
+            'contentComponent'
+        );
+
+        expect(cut.tab instanceof DefaultTab).toBeTruthy();
+    });
+
+    test('that the default content is created', () => {
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
+                options: {
+                    components: {
+                        contentComponent: jest.fn().mockImplementation(() => {
+                            return contentMock;
+                        }),
+                    },
+                },
+            };
+
+            return partial as DockviewComponent;
+        });
+
+        const cut = new DockviewPanelModel(
+            <IDockviewComponent>new accessorMock(),
+            'id',
+            'contentComponent'
+        );
+
+        expect(cut.content).toEqual(contentMock);
+    });
+
+    test('that the framework content is created', () => {
+        const content = jest.fn();
+        const contentFactory = jest.fn().mockImplementation(() => content);
+
+        accessorMock = jest.fn<DockviewComponent, []>(() => {
+            const partial: Partial<DockviewComponent> = {
+                options: {
+                    frameworkComponents: {
+                        contentComponent: contentMock,
+                    },
+                    frameworkComponentFactory: (<
+                        Partial<GroupPanelFrameworkComponentFactory>
+                    >{
+                        content: { createComponent: contentFactory },
+                    }) as GroupPanelFrameworkComponentFactory,
+                },
+            };
+
+            return partial as DockviewComponent;
+        });
+
+        const cut = new DockviewPanelModel(
+            <IDockviewComponent>new accessorMock(),
+            'id',
+            'contentComponent'
+        );
+
+        expect(contentFactory).toHaveBeenCalledWith(
+            'id',
+            'contentComponent',
+            contentMock
+        );
+        expect(cut.content).toEqual(content);
+    });
 });
diff --git a/packages/dockview-core/src/__tests__/gridview/baseComponentGridview.spec.ts b/packages/dockview-core/src/__tests__/gridview/baseComponentGridview.spec.ts
index 592598807..27e8925b1 100644
--- a/packages/dockview-core/src/__tests__/gridview/baseComponentGridview.spec.ts
+++ b/packages/dockview-core/src/__tests__/gridview/baseComponentGridview.spec.ts
@@ -114,7 +114,7 @@ describe('baseComponentGridview', () => {
             proportionalLayout: true,
         });
 
-        const events: TestPanel[] = [];
+        const events: (TestPanel | undefined)[] = [];
 
         const disposable = new CompositeDisposable(
             cut.onDidAddGroup((event) => {
diff --git a/packages/dockview-core/src/__tests__/groupview/dockviewGroupPanelModel.spec.ts b/packages/dockview-core/src/__tests__/groupview/dockviewGroupPanelModel.spec.ts
index ef2ed7cad..b00522d05 100644
--- a/packages/dockview-core/src/__tests__/groupview/dockviewGroupPanelModel.spec.ts
+++ b/packages/dockview-core/src/__tests__/groupview/dockviewGroupPanelModel.spec.ts
@@ -18,11 +18,9 @@ import { LocalSelectionTransfer, PanelTransfer } from '../../dnd/dataTransfer';
 import { CompositeDisposable } from '../../lifecycle';
 import { DockviewPanelApi } from '../../api/dockviewPanelApi';
 import { IDockviewPanel } from '../../dockview/dockviewPanel';
-import {
-    IDockviewPanelModel,
-    DockviewPanelModel,
-} from '../../dockview/dockviewPanelModel';
+import { IDockviewPanelModel } from '../../dockview/dockviewPanelModel';
 import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+import { WatermarkRendererInitParameters } from '../../dockview/types';
 
 enum GroupChangeKind2 {
     ADD_PANEL,
@@ -76,7 +74,7 @@ class Watermark implements IWatermarkRenderer {
         return 'watermark-id';
     }
 
-    init(params: GroupPanelPartInitParameters) {
+    init(params: WatermarkRendererInitParameters) {
         //
     }
 
@@ -170,7 +168,7 @@ class TestHeaderPart implements ITabRenderer {
 
 export class TestPanel implements IDockviewPanel {
     private _group: DockviewGroupPanel | undefined;
-    private _params: IGroupPanelInitParameters;
+    private _params: IGroupPanelInitParameters | undefined;
     readonly view: IDockviewPanelModel;
 
     get title() {
@@ -516,7 +514,7 @@ describe('groupview', () => {
             dockviewComponent,
             'id',
             {},
-            null
+            null as any
         );
 
         expect(cut.toJSON()).toEqual({
@@ -539,7 +537,7 @@ describe('groupview', () => {
             dockviewComponent,
             'id',
             {},
-            null
+            null as any
         );
 
         cut.locked = true;
@@ -568,25 +566,25 @@ describe('groupview', () => {
             dockviewComponent,
             'id',
             {},
-            null
+            null as any
         );
         const contentContainer = groupviewContainer
             .getElementsByClassName('content-container')
             .item(0)!.childNodes;
 
-        const panel1 = new TestPanel('id_1', null);
+        const panel1 = new TestPanel('id_1', null as any);
 
         cut.openPanel(panel1);
         expect(contentContainer.length).toBe(1);
         expect(contentContainer.item(0)).toBe(panel1.view.content.element);
 
-        const panel2 = new TestPanel('id_2', null);
+        const panel2 = new TestPanel('id_2', null as any);
 
         cut.openPanel(panel2);
         expect(contentContainer.length).toBe(1);
         expect(contentContainer.item(0)).toBe(panel2.view.content.element);
 
-        const panel3 = new TestPanel('id_2', null);
+        const panel3 = new TestPanel('id_2', null as any);
 
         cut.openPanel(panel3, { skipSetPanelActive: true });
         expect(contentContainer.length).toBe(1);
diff --git a/packages/dockview-core/src/dockview/deserializer.ts b/packages/dockview-core/src/dockview/deserializer.ts
index 5c6936c4d..82daa7381 100644
--- a/packages/dockview-core/src/dockview/deserializer.ts
+++ b/packages/dockview-core/src/dockview/deserializer.ts
@@ -1,9 +1,7 @@
-import { GroupviewPanelState, ITabRenderer } from './types';
+import { GroupviewPanelState } from './types';
 import { DockviewGroupPanel } from './dockviewGroupPanel';
 import { DockviewPanel, IDockviewPanel } from './dockviewPanel';
 import { IDockviewComponent } from './dockviewComponent';
-import { createComponent } from '../panel/componentFactory';
-import { DefaultTab } from './components/tab/defaultTab';
 import { DockviewPanelModel } from './dockviewPanelModel';
 import { DockviewApi } from '../api/component.api';
 
@@ -14,7 +12,7 @@ export interface IPanelDeserializer {
     ): IDockviewPanel;
 }
 
-// depreciated
+// @depreciated
 interface LegacyState extends GroupviewPanelState {
     view?: {
         tab?: { id: string };
@@ -42,30 +40,6 @@ export class DefaultDockviewDeserialzier implements IPanelDeserializer {
             ? viewData.tab?.id
             : panelData.tabComponent;
 
-        let tab: ITabRenderer;
-
-        if (tabComponent) {
-            tab = createComponent(
-                panelId,
-                tabComponent,
-                this.layout.options.tabComponents,
-                this.layout.options.frameworkTabComponents,
-                this.layout.options.frameworkComponentFactory?.tab,
-                () => new DefaultTab()
-            );
-        } else if (this.layout.options.defaultTabComponent) {
-            tab = createComponent(
-                panelId,
-                this.layout.options.defaultTabComponent,
-                this.layout.options.tabComponents,
-                this.layout.options.frameworkTabComponents,
-                this.layout.options.frameworkComponentFactory?.tab,
-                () => new DefaultTab()
-            );
-        } else {
-            tab = new DefaultTab();
-        }
-
         const view = new DockviewPanelModel(
             this.layout,
             panelId,
diff --git a/packages/dockview-core/src/dockview/dockviewPanelModel.ts b/packages/dockview-core/src/dockview/dockviewPanelModel.ts
index c8e2aee8f..b29bcd12c 100644
--- a/packages/dockview-core/src/dockview/dockviewPanelModel.ts
+++ b/packages/dockview-core/src/dockview/dockviewPanelModel.ts
@@ -43,8 +43,7 @@ export class DockviewPanelModel implements IDockviewPanelModel {
         readonly tabComponent?: string
     ) {
         this._content = this.createContentComponent(this.id, contentComponent);
-        this._tab =
-            this.createTabComponent(this.id, tabComponent) ?? new DefaultTab();
+        this._tab = this.createTabComponent(this.id, tabComponent);
     }
 
     init(params: GroupPanelPartInitParameters): void {
@@ -108,13 +107,26 @@ export class DockviewPanelModel implements IDockviewPanelModel {
         id: string,
         componentName?: string
     ): ITabRenderer {
-        return createComponent(
-            id,
-            componentName,
-            this.accessor.options.tabComponents || {},
-            this.accessor.options.frameworkTabComponents,
-            this.accessor.options.frameworkComponentFactory?.tab,
-            () => new DefaultTab()
-        );
+        if (componentName) {
+            return createComponent(
+                id,
+                componentName,
+                this.accessor.options.tabComponents,
+                this.accessor.options.frameworkTabComponents,
+                this.accessor.options.frameworkComponentFactory?.tab,
+                () => new DefaultTab()
+            );
+        } else if (this.accessor.options.defaultTabComponent) {
+            return createComponent(
+                id,
+                this.accessor.options.defaultTabComponent,
+                this.accessor.options.tabComponents,
+                this.accessor.options.frameworkTabComponents,
+                this.accessor.options.frameworkComponentFactory?.tab,
+                () => new DefaultTab()
+            );
+        } else {
+            return new DefaultTab();
+        }
     }
 }
diff --git a/packages/dockview/jest.config.ts b/packages/dockview/jest.config.ts
index f6b1969ca..b909c68ef 100644
--- a/packages/dockview/jest.config.ts
+++ b/packages/dockview/jest.config.ts
@@ -27,7 +27,7 @@ const config: JestConfigWithTsJest = {
         '^.+\\.tsx?$': [
             'ts-jest',
             {
-                tsconfig,
+                tsconfig: '<rootDir>/tsconfig.test.json',
             },
         ],
     },
diff --git a/packages/dockview/src/__tests__/__test_utils__/utils.ts b/packages/dockview/src/__tests__/__test_utils__/utils.ts
index ab8dc0a9e..675a30c17 100644
--- a/packages/dockview/src/__tests__/__test_utils__/utils.ts
+++ b/packages/dockview/src/__tests__/__test_utils__/utils.ts
@@ -1,5 +1,3 @@
-import * as React from 'react';
-
 export function setMockRefElement(node: Partial<HTMLElement>): void {
     const mockRef = {
         get current() {
@@ -10,5 +8,5 @@ export function setMockRefElement(node: Partial<HTMLElement>): void {
         },
     };
 
-    jest.spyOn(React, 'useRef').mockReturnValueOnce(mockRef);
+    jest.spyOn(require('react'), 'useRef').mockReturnValueOnce(mockRef);
 }
diff --git a/packages/dockview/src/__tests__/dockview/dockview.spec.tsx b/packages/dockview/src/__tests__/dockview/dockview.spec.tsx
index 2c55b29b7..6fe0872a7 100644
--- a/packages/dockview/src/__tests__/dockview/dockview.spec.tsx
+++ b/packages/dockview/src/__tests__/dockview/dockview.spec.tsx
@@ -48,7 +48,7 @@ describe('gridview react', () => {
 
         render(<DockviewReact components={components} onReady={onReady} />);
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/gridview/gridview.spec.tsx b/packages/dockview/src/__tests__/gridview/gridview.spec.tsx
index 92f81f4c3..0881e00b4 100644
--- a/packages/dockview/src/__tests__/gridview/gridview.spec.tsx
+++ b/packages/dockview/src/__tests__/gridview/gridview.spec.tsx
@@ -59,7 +59,7 @@ describe('gridview react', () => {
             />
         );
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/paneview/paneview.spec.tsx b/packages/dockview/src/__tests__/paneview/paneview.spec.tsx
index 0a69965f0..830861e89 100644
--- a/packages/dockview/src/__tests__/paneview/paneview.spec.tsx
+++ b/packages/dockview/src/__tests__/paneview/paneview.spec.tsx
@@ -46,7 +46,7 @@ describe('gridview react', () => {
 
         render(<PaneviewReact components={components} onReady={onReady} />);
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/react.spec.tsx b/packages/dockview/src/__tests__/react.spec.tsx
index 2abf76845..298d96fed 100644
--- a/packages/dockview/src/__tests__/react.spec.tsx
+++ b/packages/dockview/src/__tests__/react.spec.tsx
@@ -18,7 +18,7 @@ describe('react', () => {
 
             render(<TestWrapper onReady={onReady} component={Component} />);
 
-            expect(api).toBeTruthy();
+            expect(api!).toBeTruthy();
 
             expect(screen.getByTestId('valueA').textContent).toBe('stringA');
             expect(screen.getByTestId('valueB').textContent).toBe('42');
@@ -60,7 +60,7 @@ const TestWrapper = (props: {
 
     React.useEffect(() => {
         const cut = new ReactPart<TestInterface>(
-            ref.current,
+            ref.current!,
             {
                 addPortal: (portal: React.ReactPortal) => {
                     setPortal((_) => [..._, portal]);
diff --git a/packages/dockview/src/__tests__/react/dockview/dockview.spec.tsx b/packages/dockview/src/__tests__/react/dockview/dockview.spec.tsx
index b8e9f1bcb..12048cac5 100644
--- a/packages/dockview/src/__tests__/react/dockview/dockview.spec.tsx
+++ b/packages/dockview/src/__tests__/react/dockview/dockview.spec.tsx
@@ -47,7 +47,7 @@ describe('dockview', () => {
 
         render(<DockviewReact components={components} onReady={onReady} />);
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/react/gridview/gridview.spec.tsx b/packages/dockview/src/__tests__/react/gridview/gridview.spec.tsx
index 8e76030d9..5e5ff70e9 100644
--- a/packages/dockview/src/__tests__/react/gridview/gridview.spec.tsx
+++ b/packages/dockview/src/__tests__/react/gridview/gridview.spec.tsx
@@ -58,7 +58,7 @@ describe('gridview react', () => {
             />
         );
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/react/paneview/paneview.spec.tsx b/packages/dockview/src/__tests__/react/paneview/paneview.spec.tsx
index 3223a8503..4dc8b8198 100644
--- a/packages/dockview/src/__tests__/react/paneview/paneview.spec.tsx
+++ b/packages/dockview/src/__tests__/react/paneview/paneview.spec.tsx
@@ -46,7 +46,7 @@ describe('gridview react', () => {
 
         render(<PaneviewReact components={components} onReady={onReady} />);
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/react/react.spec.tsx b/packages/dockview/src/__tests__/react/react.spec.tsx
index f9799c0a5..b89d09d74 100644
--- a/packages/dockview/src/__tests__/react/react.spec.tsx
+++ b/packages/dockview/src/__tests__/react/react.spec.tsx
@@ -18,7 +18,7 @@ describe('react', () => {
 
             render(<TestWrapper onReady={onReady} component={Component} />);
 
-            expect(api).toBeTruthy();
+            expect(api!).toBeTruthy();
 
             expect(screen.getByTestId('valueA').textContent).toBe('stringA');
             expect(screen.getByTestId('valueB').textContent).toBe('42');
@@ -60,7 +60,7 @@ const TestWrapper = (props: {
 
     React.useEffect(() => {
         const cut = new ReactPart<TestInterface>(
-            ref.current,
+            ref.current!,
             {
                 addPortal: (portal: React.ReactPortal) => {
                     setPortal((_) => [..._, portal]);
diff --git a/packages/dockview/src/__tests__/react/splitview/splitview.spec.tsx b/packages/dockview/src/__tests__/react/splitview/splitview.spec.tsx
index 852171aa9..9ffc01974 100644
--- a/packages/dockview/src/__tests__/react/splitview/splitview.spec.tsx
+++ b/packages/dockview/src/__tests__/react/splitview/splitview.spec.tsx
@@ -58,7 +58,7 @@ describe('splitview react', () => {
             />
         );
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/packages/dockview/src/__tests__/splitview/splitview.spec.tsx b/packages/dockview/src/__tests__/splitview/splitview.spec.tsx
index e0da9dd72..34e0027db 100644
--- a/packages/dockview/src/__tests__/splitview/splitview.spec.tsx
+++ b/packages/dockview/src/__tests__/splitview/splitview.spec.tsx
@@ -58,7 +58,7 @@ describe('splitview react', () => {
             />
         );
 
-        expect(api.width).toBe(650);
-        expect(api.height).toBe(450);
+        expect(api!.width).toBe(650);
+        expect(api!.height).toBe(450);
     });
 });
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 77f0e8b99..2ca86a1c1 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -21,5 +21,6 @@
             "ES2019",
             "DOM"
         ]
-    }
+    },
+    "exclude": ["**/*.spec.ts"]
 }
diff --git a/tsconfig.test.json b/tsconfig.test.json
index d58b7d79f..5001874b2 100644
--- a/tsconfig.test.json
+++ b/tsconfig.test.json
@@ -1,22 +1,7 @@
-  
 {
+    "extends": "./tsconfig.base.json",
     "compilerOptions": {
-        "module": "commonjs",
-        "target": "es2019",
-        "sourceMap": true,
-        "declaration": true,
-        "jsx": "react",
-        "noImplicitReturns": true,
-        "noImplicitAny": true,
-        "allowUnreachableCode": false,
-        "forceConsistentCasingInFileNames": true,
-        // "strict": true,
-        "strictBindCallApply": true, // pass
-        "alwaysStrict": true, // pass
-        "noImplicitThis": true, // pass
-        "strictFunctionTypes": true, // pass
-        "strictNullChecks": false,
-        "strictPropertyInitialization": false,
+        "jsx": "react-jsx"
     },
-    "exclude": ["node_modules", "dist"]
-}
\ No newline at end of file
+    "include": ["**/*.spec.ts"]
+}