Function createMemoryHistory

packages/history/src/index.ts:578–631

(
  opts: {
    initialEntries: Array<string>
    initialIndex?: number
  } = {
    initialEntries: ['/'],
  },
)

 * @link https://tanstack.com/router/latest/docs/framework/react/guide/history-types
 */
export function createMemoryHistory(
  opts: {
    initialEntries: Array<string>
    initialIndex?: number
  } = {
    initialEntries: ['/'],
  },
): RouterHistory {
  const entries = opts.initialEntries
  let index = opts.initialIndex
    ? Math.min(Math.max(opts.initialIndex, 0), entries.length - 1)
    : entries.length - 1
  const states = entries.map((_entry, index) =>
    assignKeyAndIndex(index, undefined),
  )

  const getLocation = () => parseHref(entries[index]!, states[index])

  let blockers: Array<NavigationBlocker> = []
  const _getBlockers = () => blockers
  const _setBlockers = (newBlockers: Array<NavigationBlocker>) =>
    (blockers = newBlockers)

  return createHistory({
    getLocation,
    getLength: () => entries.length,
    pushState: (path, state) => {
      // Removes all subsequent entries after the current index to start a new branch
      if (index < entries.length - 1) {
        entries.splice(index + 1)
        states.splice(index + 1)
      }
      states.push(state)
      entries.push(path)
      index = Math.max(entries.length - 1, 0)
    },
    replaceState: (path, state) => {
      states[index] = state
      entries[index] = path
    },
    back: () => {
      index = Math.max(index - 1, 0)
    },
    forward: () => {
      index = Math.min(index + 1, entries.length - 1)
    },
    go: (n) => {
      index = Math.min(Math.max(index + n, 0), entries.length - 1)
    },
    createHref: (path) => path,
    getBlockers: _getBlockers,
    setBlockers: _setBlockers,
  })
}

/**
 * Sanitize a path to prevent open redirect vulnerabilities.