add fast insert-into-sorted-list utils.

utils.test.js

@@ -0,0 +1,183 @@
+/* eslint-env jest */
+
+const {utils} = require('./lib/nostr.cjs')
+
+const {insertEventIntoAscendingList, insertEventIntoDescendingList} = utils
+
+describe('inserting into a desc sorted list of events', () => {
+  test('insert into an empty list', async () => {
+    const list0 = []
+    expect(
+      insertEventIntoDescendingList(list0, {id: 'abc', created_at: 10})
+    ).toHaveLength(1)
+  })
+
+  test('insert in the beginning of a list', async () => {
+    const list0 = [{created_at: 20}, {created_at: 10}]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(3)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the beginning of a list with same created_at', async () => {
+    const list0 = [{created_at: 30}, {created_at: 20}, {created_at: 10}]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(4)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the middle of a list', async () => {
+    const list0 = [
+      {created_at: 30},
+      {created_at: 20},
+      {created_at: 10},
+      {created_at: 1}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 15
+    })
+    expect(list1).toHaveLength(5)
+    expect(list1[2].id).toBe('abc')
+  })
+
+  test('insert in the end of a list', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 10}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 5
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-1)[0].id).toBe('abc')
+  })
+
+  test('insert in the last-to-end of a list with same created_at', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 10}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 10
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-2)[0].id).toBe('abc')
+  })
+
+  test('do not insert duplicates', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 10, id: 'abc'}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 10
+    })
+    expect(list1).toHaveLength(3)
+  })
+})
+
+describe('inserting into a asc sorted list of events', () => {
+  test('insert into an empty list', async () => {
+    const list0 = []
+    expect(
+      insertEventIntoAscendingList(list0, {id: 'abc', created_at: 10})
+    ).toHaveLength(1)
+  })
+
+  test('insert in the beginning of a list', async () => {
+    const list0 = [{created_at: 10}, {created_at: 20}]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 1
+    })
+    expect(list1).toHaveLength(3)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the beginning of a list with same created_at', async () => {
+    const list0 = [{created_at: 10}, {created_at: 20}, {created_at: 30}]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 10
+    })
+    expect(list1).toHaveLength(4)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the middle of a list', async () => {
+    const list0 = [
+      {created_at: 10},
+      {created_at: 20},
+      {created_at: 30},
+      {created_at: 40}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 25
+    })
+    expect(list1).toHaveLength(5)
+    expect(list1[2].id).toBe('abc')
+  })
+
+  test('insert in the end of a list', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 40}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 50
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-1)[0].id).toBe('abc')
+  })
+
+  test('insert in the last-to-end of a list with same created_at', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 30}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-2)[0].id).toBe('abc')
+  })
+
+  test('do not insert duplicates', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 30, id: 'abc'}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(3)
+  })
+})