diff --git a/src/extensions/selectable.ts b/src/extensions/selectable.ts
index 703724e..0649086 100644
--- a/src/extensions/selectable.ts
+++ b/src/extensions/selectable.ts
@@ -51,8 +51,14 @@ export class Selector<E extends SelectorEntity> {
   }
 
   async add(entity: E, accumulate: boolean) {
-    if (!accumulate) await this.unselectAll()
-    this.entities.set(`${entity.label}_${entity.id}`, entity)
+    const id = `${entity.label}_${entity.id}`
+
+    if (!accumulate) {
+      await this.unselect(Array.from(this.entities.values())
+        .filter(item => item.label !== entity.label || item.id !== entity.id))
+    }
+
+    this.entities.set(id, entity)
   }
 
   async remove(entity: Pick<E, 'label' | 'id'>) {
@@ -65,8 +71,12 @@ export class Selector<E extends SelectorEntity> {
     }
   }
 
+  async unselect(entities: Iterable<Pick<E, 'label' | 'id'>>) {
+    await Promise.all(Array.from(entities).map(entity => this.remove(entity)))
+  }
+
   async unselectAll() {
-    await Promise.all([...Array.from(this.entities.values())].map(item => this.remove(item)))
+    await this.unselect(this.entities.values())
   }
 
   async translate(dx: number, dy: number) {
diff --git a/test/selectable.test.ts b/test/selectable.test.ts
new file mode 100644
index 0000000..c51e515
--- /dev/null
+++ b/test/selectable.test.ts
@@ -0,0 +1,235 @@
+import { NodeEditor } from 'rete'
+
+import { selectableNodes, Selector, selector, type SelectorEntity } from '../src/extensions/selectable'
+
+type Pipe = (context: unknown) => Promise<unknown>
+
+type TestNode = {
+  id: string
+  selected?: boolean
+}
+
+function createEntity(id: string) {
+  return {
+    label: 'node',
+    id,
+    unselect: jest.fn(),
+    translate: jest.fn()
+  }
+}
+
+function createSelectableContext(accumulate = false) {
+  const pipes: Pipe[] = []
+  const update = jest.fn()
+  const nodes = new Map<string, TestNode>([
+    ['n1', { id: 'n1' }],
+    ['n2', { id: 'n2' }]
+  ])
+  const editor = {
+    getNode: (id: string) => nodes.get(id)
+  }
+  const accumulating = { active: jest.fn(() => accumulate) }
+  const core = selector()
+  const base = {
+    nodeViews: new Map<string, { position: { x: number, y: number }, translate: jest.Mock }>(),
+    connectionViews: new Map(),
+    area: {
+      content: {
+        holder: {},
+        add: jest.fn(),
+        remove: jest.fn(),
+        reorder: jest.fn()
+      }
+    },
+    addPipe: (pipe: Pipe) => {
+      pipes.push(pipe)
+    },
+    parentScope: (scope: unknown) => {
+      if (scope === NodeEditor) return editor
+      throw new Error('unexpected scope')
+    },
+    update
+  }
+
+  const api = selectableNodes(base as never, core, { accumulating })
+
+  return {
+    pipe: pipes[0],
+    core,
+    nodes,
+    update,
+    accumulating,
+    api
+  }
+}
+
+describe('Selector', () => {
+  it('selects a single entity without accumulate', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+
+    await core.add(first, false)
+
+    expect(core.isSelected(first)).toBe(true)
+    expect(core.entities.size).toBe(1)
+    expect(first.unselect).not.toHaveBeenCalled()
+  })
+
+  it('replaces selection when another entity is picked without accumulate', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+    const second = createEntity('n2')
+
+    await core.add(first, false)
+    await core.add(second, false)
+
+    expect(core.isSelected(first)).toBe(false)
+    expect(core.isSelected(second)).toBe(true)
+    expect(core.entities.size).toBe(1)
+    expect(first.unselect).toHaveBeenCalledTimes(1)
+    expect(second.unselect).not.toHaveBeenCalled()
+  })
+
+  it('accumulates entities when accumulate is enabled', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+    const second = createEntity('n2')
+
+    await core.add(first, false)
+    await core.add(second, true)
+
+    expect(core.isSelected(first)).toBe(true)
+    expect(core.isSelected(second)).toBe(true)
+    expect(core.entities.size).toBe(2)
+    expect(first.unselect).not.toHaveBeenCalled()
+    expect(second.unselect).not.toHaveBeenCalled()
+  })
+
+  it('reduces multi-selection to the clicked entity without accumulate', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+    const second = createEntity('n2')
+
+    await core.add(first, false)
+    await core.add(second, true)
+    await core.add(first, false)
+
+    expect(core.isSelected(first)).toBe(true)
+    expect(core.isSelected(second)).toBe(false)
+    expect(core.entities.size).toBe(1)
+    expect(second.unselect).toHaveBeenCalledTimes(1)
+  })
+
+  it('clears all entities on unselectAll', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+    const second = createEntity('n2')
+
+    await core.add(first, false)
+    await core.add(second, true)
+    await core.unselectAll()
+
+    expect(core.entities.size).toBe(0)
+    expect(first.unselect).toHaveBeenCalledTimes(1)
+    expect(second.unselect).toHaveBeenCalledTimes(1)
+  })
+
+  it('does not unselect when re-adding the sole selected entity', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+
+    await core.add(first, false)
+    await core.add(first, false)
+
+    expect(core.isSelected(first)).toBe(true)
+    expect(core.entities.size).toBe(1)
+    expect(first.unselect).not.toHaveBeenCalled()
+  })
+
+  it('does not unselect the clicked entity when reducing multi-selection without accumulate', async () => {
+    const core = new Selector<SelectorEntity>()
+    const first = createEntity('n1')
+    const second = createEntity('n2')
+
+    await core.add(first, false) // {n1}
+    await core.add(second, true) // {n1, n2}
+    await core.add(first, false) // click already selected n1 without Ctrl => should keep n1 selected, only remove n2
+
+    expect(core.isSelected(first)).toBe(true)
+    expect(core.isSelected(second)).toBe(false)
+    expect(core.entities.size).toBe(1)
+
+    // unselect must be invoked only for the entity that is removed from selection (n2)
+    expect(second.unselect).toHaveBeenCalledTimes(1)
+    expect(first.unselect).not.toHaveBeenCalled()
+  })
+})
+
+describe('selectableNodes', () => {
+  it('selects a node on nodepicked and marks it as selected', async () => {
+    const { pipe, nodes, update } = createSelectableContext()
+
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+
+    expect(nodes.get('n1')?.selected).toBe(true)
+    expect(update).toHaveBeenCalledWith('node', 'n1')
+  })
+
+  it('accumulates nodes when accumulate mode is active', async () => {
+    const { pipe, core, nodes, accumulating } = createSelectableContext()
+
+    accumulating.active.mockReturnValueOnce(false).mockReturnValueOnce(true)
+
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+    await pipe({ type: 'nodepicked', data: { id: 'n2' } })
+
+    expect(nodes.get('n1')?.selected).toBe(true)
+    expect(nodes.get('n2')?.selected).toBe(true)
+    expect(core.entities.size).toBe(2)
+  })
+
+  it('clears selection on background pointerup click', async () => {
+    const { pipe, core, nodes } = createSelectableContext()
+
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+    await pipe({ type: 'pointerdown', data: {} })
+    await pipe({ type: 'pointerup', data: {} })
+
+    expect(nodes.get('n1')?.selected).toBe(false)
+    expect(core.entities.size).toBe(0)
+  })
+
+  it('does not re-render when re-picking the sole selected node', async () => {
+    const { pipe, nodes, update } = createSelectableContext()
+
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+
+    expect(nodes.get('n1')?.selected).toBe(true)
+    expect(update).toHaveBeenCalledTimes(1)
+  })
+
+  it('does not re-render when reducing multi-selection by clicking already selected node without accumulate', async () => {
+    const { pipe, nodes, update, accumulating } = createSelectableContext()
+
+    accumulating.active
+      .mockReturnValueOnce(false) // n1 without Ctrl
+      .mockReturnValueOnce(true) // n2 with Ctrl => {n1, n2}
+      .mockReturnValueOnce(false) // click n1 without Ctrl => should keep n1 selected
+
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+    await pipe({ type: 'nodepicked', data: { id: 'n2' } })
+    await pipe({ type: 'nodepicked', data: { id: 'n1' } })
+
+    expect(nodes.get('n1')?.selected).toBe(true)
+    expect(nodes.get('n2')?.selected).toBe(false)
+
+    /*
+     * update calls:
+     * 1) select n1
+     * 2) select n2
+     * 3) unselect n2 when reducing to single selection (no unselect/select for n1)
+     */
+    expect(update).toHaveBeenCalledTimes(3)
+  })
+})