diff --git a/packages/block-editor/src/components/provider/test/use-block-sync.js b/packages/block-editor/src/components/provider/test/use-block-sync.js
new file mode 100644
index 00000000000000..29b6b15ed3f1d0
--- /dev/null
+++ b/packages/block-editor/src/components/provider/test/use-block-sync.js
@@ -0,0 +1,368 @@
+/**
+ * External dependencies
+ */
+import { create, act } from 'react-test-renderer';
+
+/**
+ * Internal dependencies
+ */
+import useBlockSync from '../use-block-sync';
+import withRegistryProvider from '../with-registry-provider';
+import * as blockEditorActions from '../../../store/actions';
+
+const TestWrapper = withRegistryProvider( ( props ) => {
+	if ( props.setRegistry ) {
+		props.setRegistry( props.registry );
+	}
+	useBlockSync( props );
+	return <p>Test.</p>;
+} );
+
+describe( 'useBlockSync hook', () => {
+	afterEach( () => {
+		jest.clearAllMocks();
+	} );
+
+	it( 'resets the block-editor blocks when the controll value changes', async () => {
+		const fakeBlocks = [];
+		const resetBlocks = jest.spyOn( blockEditorActions, 'resetBlocks' );
+		const replaceInnerBlocks = jest.spyOn(
+			blockEditorActions,
+			'replaceInnerBlocks'
+		);
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		let root;
+		await act( async () => {
+			root = create(
+				<TestWrapper
+					value={ fakeBlocks }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		// Reset blocks should be called on mount.
+		expect( onChange ).not.toHaveBeenCalled();
+		expect( onInput ).not.toHaveBeenCalled();
+		expect( replaceInnerBlocks ).not.toHaveBeenCalled();
+		expect( resetBlocks ).toHaveBeenCalledWith( fakeBlocks );
+
+		const testBlocks = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+		await act( async () => {
+			root.update(
+				<TestWrapper
+					value={ testBlocks }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		// Reset blocks should be called when the incoming value changes.
+		expect( onChange ).not.toHaveBeenCalled();
+		expect( onInput ).not.toHaveBeenCalled();
+		expect( replaceInnerBlocks ).not.toHaveBeenCalled();
+		expect( resetBlocks ).toHaveBeenCalledWith( testBlocks );
+	} );
+
+	it( 'replaces the inner blocks of a block when the control value changes if a clientId is passed', async () => {
+		const fakeBlocks = [];
+		const replaceInnerBlocks = jest.spyOn(
+			blockEditorActions,
+			'replaceInnerBlocks'
+		);
+		const resetBlocks = jest.spyOn( blockEditorActions, 'resetBlocks' );
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		let root;
+		await act( async () => {
+			root = create(
+				<TestWrapper
+					clientId="test"
+					value={ fakeBlocks }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		expect( resetBlocks ).not.toHaveBeenCalled();
+		expect( onChange ).not.toHaveBeenCalled();
+		expect( onInput ).not.toHaveBeenCalled();
+		expect( replaceInnerBlocks ).toHaveBeenCalledWith(
+			'test', // It should use the given client ID.
+			fakeBlocks, // It should use the controlled blocks value.
+			false // It shoudl not update the selection state.
+		);
+
+		const testBlocks = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+		await act( async () => {
+			root.update(
+				<TestWrapper
+					clientId="test"
+					value={ testBlocks }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		// Reset blocks should be called when the incoming value changes.
+		expect( onChange ).not.toHaveBeenCalled();
+		expect( onInput ).not.toHaveBeenCalled();
+		expect( resetBlocks ).not.toHaveBeenCalled();
+		expect( replaceInnerBlocks ).toHaveBeenCalledWith(
+			'test',
+			testBlocks,
+			false
+		);
+	} );
+
+	it( 'does not add the controlled blocks to the block-editor store if the store already contains them', async () => {
+		const replaceInnerBlocks = jest.spyOn(
+			blockEditorActions,
+			'replaceInnerBlocks'
+		);
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		const value1 = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+		let root;
+		let registry;
+		const setRegistry = ( reg ) => {
+			registry = reg;
+		};
+		await act( async () => {
+			root = create(
+				<TestWrapper
+					setRegistry={ setRegistry }
+					clientId="test"
+					value={ value1 }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		registry
+			.dispatch( 'core/block-editor' )
+			.updateBlockAttributes( 'a', { foo: 2 } );
+
+		const newBlockValue = registry
+			.select( 'core/block-editor' )
+			.getBlocks( 'test' );
+		replaceInnerBlocks.mockClear();
+
+		// Assert that the reference has changed so that the side effect will be
+		// triggered once more.
+		expect( newBlockValue ).not.toBe( value1 );
+
+		await act( async () => {
+			root.update(
+				<TestWrapper
+					clientId="test"
+					value={ newBlockValue }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		// replaceInnerBlocks should not be called when the controlling
+		// block value is the same as what already exists in the store.
+		expect( replaceInnerBlocks ).not.toHaveBeenCalled();
+	} );
+
+	it( 'sets a block as an inner block controller if a clientId is provided', async () => {
+		const setAsController = jest.spyOn(
+			blockEditorActions,
+			'setHasControlledInnerBlocks'
+		);
+
+		await act( async () => {
+			create(
+				<TestWrapper
+					clientId="test"
+					value={ [] }
+					onChange={ jest.fn() }
+					onInput={ jest.fn() }
+				/>
+			);
+		} );
+		expect( setAsController ).toHaveBeenCalledWith( 'test', true );
+	} );
+
+	it( 'calls onInput when a non-persistent block change occurs', async () => {
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		const value1 = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+		let registry;
+		const setRegistry = ( reg ) => {
+			registry = reg;
+		};
+		await act( async () => {
+			create(
+				<TestWrapper
+					setRegistry={ setRegistry }
+					clientId="test"
+					value={ value1 }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+		onChange.mockClear();
+		onInput.mockClear();
+
+		// Create a non-persistent change.
+		registry
+			.dispatch( 'core/block-editor' )
+			.__unstableMarkNextChangeAsNotPersistent();
+		registry
+			.dispatch( 'core/block-editor' )
+			.updateBlockAttributes( 'a', { foo: 2 } );
+
+		expect( onInput ).toHaveBeenCalledWith(
+			[ { clientId: 'a', innerBlocks: [], attributes: { foo: 2 } } ],
+			{ selectionEnd: {}, selectionStart: {} }
+		);
+		expect( onChange ).not.toHaveBeenCalled();
+	} );
+
+	it( 'calls onChange if a persistent change occurs', async () => {
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		const value1 = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+		let registry;
+		const setRegistry = ( reg ) => {
+			registry = reg;
+		};
+		await act( async () => {
+			create(
+				<TestWrapper
+					setRegistry={ setRegistry }
+					clientId="test"
+					value={ value1 }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+		onChange.mockClear();
+		onInput.mockClear();
+
+		// Create a persistent change.
+		registry
+			.dispatch( 'core/block-editor' )
+			.updateBlockAttributes( 'a', { foo: 2 } );
+
+		expect( onChange ).toHaveBeenCalledWith(
+			[ { clientId: 'a', innerBlocks: [], attributes: { foo: 2 } } ],
+			{ selectionEnd: {}, selectionStart: {} }
+		);
+		expect( onInput ).not.toHaveBeenCalled();
+	} );
+
+	it( 'avoids updating the parent if there is a pending incoming change', async () => {
+		const replaceInnerBlocks = jest.spyOn(
+			blockEditorActions,
+			'replaceInnerBlocks'
+		);
+
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		const value1 = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+
+		await act( async () => {
+			create(
+				<TestWrapper
+					clientId="test"
+					value={ value1 }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+		onChange.mockClear();
+		onInput.mockClear();
+		replaceInnerBlocks.mockClear();
+
+		await act( async () => {
+			create(
+				<TestWrapper
+					clientId="test"
+					value={ [] }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+
+		expect( replaceInnerBlocks ).toHaveBeenCalledWith( 'test', [], false );
+		expect( onChange ).not.toHaveBeenCalled();
+		expect( onInput ).not.toHaveBeenCalled();
+	} );
+
+	it( 'avoids updating the block-editor store if there is a pending outgoint change', async () => {
+		const replaceInnerBlocks = jest.spyOn(
+			blockEditorActions,
+			'replaceInnerBlocks'
+		);
+
+		const onChange = jest.fn();
+		const onInput = jest.fn();
+
+		const value1 = [
+			{ clientId: 'a', innerBlocks: [], attributes: { foo: 1 } },
+		];
+
+		let registry;
+		const setRegistry = ( reg ) => {
+			registry = reg;
+		};
+		await act( async () => {
+			create(
+				<TestWrapper
+					setRegistry={ setRegistry }
+					clientId="test"
+					value={ value1 }
+					onChange={ onChange }
+					onInput={ onInput }
+				/>
+			);
+		} );
+		onChange.mockClear();
+		onInput.mockClear();
+		replaceInnerBlocks.mockClear();
+
+		registry
+			.dispatch( 'core/block-editor' )
+			.updateBlockAttributes( 'a', { foo: 2 } );
+
+		expect( replaceInnerBlocks ).not.toHaveBeenCalled();
+		expect( onChange ).toHaveBeenCalledWith(
+			[ { clientId: 'a', innerBlocks: [], attributes: { foo: 2 } } ],
+			{ selectionEnd: {}, selectionStart: {} }
+		);
+		expect( onInput ).not.toHaveBeenCalled();
+	} );
+} );