RTT-dsl-draft-doTest.js

const expectIsWithin = text => {
  const { state, entityMatch } = createStateAndEntityMatch(text)
  return expect(isWithinEntityMatch(state, entityMatch))
}

export const DELIM_START = '{'
export const DELIM_END = '}'
/**
 * Creates a DraftJS State (content) Interpreting {...} as entities.
 * As it uses `createState()` it supports the "selection" DSL.
 */
const createStateAndEntityMatch = text => {
  const state = createState(text)
  const initialSelection = state.getSelection()
  return {
    state: pipe(
      updateContent('create-entity',
        createEntityOnSelection('myEntity', 'MUTABLE', () => createSelectionOnBlock(
          state.getCurrentContent().getFirstBlock().getKey(),
          { anchorOffset: text.indexOf(DELIM_START), focusOffset: text.indexOf(DELIM_END) }
        ))
      ),
      forceSelection(() => initialSelection)
    )(state),
    entityMatch: {
      start: text.indexOf(DELIM_START),
      end: text.indexOf(DELIM_END),
    }
  }
}

// UTILITY to create a content with a single block using a "DSL" to specify the selection
// Like this   "Hello [>World>] how are you ?"
// Selection range is specified either by [> ... >]  for left to right
// or [< ... <] for right to left
const createState = (...blockLines) => {
  // parse lines
  const parsedBlocks = blockLines.reduce((acc, dslText) => {
    const { text, anchorOffset, focusOffset } = createStateForText(dslText)
    const block = {
      key: uuid(),
      text,
      type: 'unstyled',
      depth: 0,
      inlineStyleRanges: [],
      entityRanges: [],
      data: {}
    }
    acc.blocks.push(block)
    if (!acc.selection && anchorOffset !== undefined) {
      acc.selection = {
        anchorKey: block.key,
        anchorOffset,
        focusKey: block.key,
        focusOffset,
        isBackward: focusOffset < anchorOffset
      }
    }
    return acc
  }, { blocks: [] })
  

  // create state
  const state = createEditorStateFromRawContent({ blocks: parsedBlocks.blocks, entityMap: {} })
  // select
  return parsedBlocks.selection ?
    EditorState.forceSelection(state, createSelectionOnBlock(parsedBlocks.selection.anchorKey, parsedBlocks.selection))
    : state
}

export const createStateForText = text => {
  const ltrSelectionIdx = text.indexOf('[>')
  if (ltrSelectionIdx >= 0) {
    return {
      text: text.replace(/(\[>|>\])/g, ''),
      anchorOffset: ltrSelectionIdx,
      focusOffset: text.substring(ltrSelectionIdx + 2).indexOf('>]') + ltrSelectionIdx
    }
  }
  const rtlSelectionIdx = text.indexOf('[<')
  if (rtlSelectionIdx >= 0) {
    return {
      text: text.replace(/(\[<|<\])/g, ''),
      focusOffset: rtlSelectionIdx,
      anchorOffset: text.substring(rtlSelectionIdx + 2).indexOf('<]') + rtlSelectionIdx
    }
  }
  const cursorPosition = text.indexOf('[|]')
  if (cursorPosition >= 0) {
    return {
      text: text.replace(/(\[\|\])/g, ''),
      focusOffset: cursorPosition,
      anchorOffset: cursorPosition,
    }
  }
  return { text }
}