[FormControlRange-interactive-basic.html]
  [Insertion: at start boundary keeps start; end extends (multi-char) (input).]
    expected: FAIL

  [Insertion: inside range extends end by length (input).]
    expected: FAIL

  [Insertion: at end boundary leaves offsets unchanged (multi-char) (input).]
    expected: FAIL

  [Equal-length replacement: single char inside range (input).]
    expected: FAIL

  [Deletion: backspace before range shifts both left (input).]
    expected: FAIL

  [Deletion: forward delete inside range contracts end by 1 (input).]
    expected: FAIL

  [Deletion: forward delete at end boundary no effect on range (input).]
    expected: FAIL

  [Deletion: backspace at control start is no-op (input).]
    expected: FAIL

  [Insertion: at start boundary keeps start; end extends (multi-char) (textarea).]
    expected: FAIL

  [Insertion: inside range extends end by length (textarea).]
    expected: FAIL

  [Insertion: at end boundary leaves offsets unchanged (multi-char) (textarea).]
    expected: FAIL

  [Equal-length replacement: single char inside range (textarea).]
    expected: FAIL

  [Deletion: backspace before range shifts both left (textarea).]
    expected: FAIL

  [Deletion: forward delete inside range contracts end by 1 (textarea).]
    expected: FAIL

  [Deletion: forward delete at end boundary no effect on range (textarea).]
    expected: FAIL

  [Deletion: backspace at control start is no-op (textarea).]
    expected: FAIL