// src/editor/__tests__/inline-semantic-ops.test.ts
import { describe, it, expect } from 'vitest'
import type { ChangeSpec } from '@codemirror/state'
import { inlineSemanticTextChangeFromChangeSpec } from '../inline-semantic-ops'

describe('inlineSemanticTextChangeFromChangeSpec', () => {
  it('extracts a text change from a matching change spec', () => {
    expect(inlineSemanticTextChangeFromChangeSpec({ from: 2, to: 5, insert: 'abc' }))
      .toEqual({ from: 2, to: 5, insert: 'abc' })
  })

  it('returns undefined for non-object specs', () => {
    expect(inlineSemanticTextChangeFromChangeSpec('plain text' as unknown as ChangeSpec)).toBeUndefined()
    expect(inlineSemanticTextChangeFromChangeSpec([{ from: 0, insert: 'x' }] as unknown as ChangeSpec)).toBeUndefined()
    expect(inlineSemanticTextChangeFromChangeSpec(null as unknown as ChangeSpec)).toBeUndefined()
  })

  it('returns undefined for objects missing the required fields', () => {
    expect(inlineSemanticTextChangeFromChangeSpec({ from: 0, to: 1 } as unknown as ChangeSpec)).toBeUndefined()
    expect(inlineSemanticTextChangeFromChangeSpec({ from: 0, insert: 'x' } as unknown as ChangeSpec)).toBeUndefined()
    expect(inlineSemanticTextChangeFromChangeSpec({ to: 1, insert: 'x' } as unknown as ChangeSpec)).toBeUndefined()
  })

  it('returns undefined when the insert value is not a string', () => {
    expect(inlineSemanticTextChangeFromChangeSpec({ from: 0, to: 1, insert: 42 } as unknown as ChangeSpec)).toBeUndefined()
  })
})