| case | dash | bash | mksh | osh | osh_ALT | description |
| 0 | pass | pass | pass | pass | pass | "${empty:-}" |
| 1 | pass | pass | pass | pass | pass | ${empty:-} |
| 2 | pass | pass | pass | pass | pass | :- |
| 3 | pass | pass | pass | pass | pass | - |
| 4 | pass | pass | pass | pass | pass | Inner single quotes |
| 5 | pass | pass | pass | pass | pass | Inner single quotes, outer double quotes |
| 6 | pass | pass | pass | pass | pass | Inner double quotes |
| 7 | pass | pass | pass | pass | pass | Inner double quotes, outer double quotes |
| 8 | pass | pass | pass | pass | pass | Multiple words: no quotes |
| 9 | pass | pass | pass | pass | pass | Multiple words: no outer quotes, inner single quotes |
| 10 | pass | pass | pass | pass | pass | Multiple words: no outer quotes, inner double quotes |
| 11 | pass | pass | pass | pass | pass | Multiple words: outer double quotes, no inner quotes |
| 12 | pass | pass | pass | pass | pass | Multiple words: outer double quotes, inner double quotes |
| 13 | pass | pass | pass | pass | pass | Multiple words: outer double quotes, inner single quotes |
| 14 | pass | pass | pass | pass | pass | Mixed inner quotes |
| 15 | pass | pass | pass | pass | pass | Mixed inner quotes with outer quotes |
| 16 | pass | pass | pass | pass | pass | Var with multiple words: no quotes |
| 17 | pass | pass | pass | pass | pass | Multiple words: no outer quotes, inner single quotes |
| 18 | pass | pass | pass | pass | pass | Multiple words: no outer quotes, inner double quotes |
| 19 | pass | pass | pass | pass | pass | Multiple words: outer double quotes, no inner quotes |
| 20 | pass | pass | pass | pass | pass | Multiple words: outer double quotes, inner double quotes |
| 21 | pass | pass | pass | pass | pass | Multiple words: outer double quotes, inner single quotes |
| 22 | pass | pass | pass | pass | pass | No outer quotes, Multiple internal quotes |
| 23 | pass | pass | pass | pass | pass | Strip a string with single quotes, unquoted |
| 24 | pass | pass | pass | pass | pass | Strip a string with single quotes, double quoted |
| 25 | pass | pass | pass | pass | pass | The string to strip is space sensitive |
| 26 | pass | pass | pass | pass | pass | The string to strip can be single quoted, outer is unquoted |
| 27 | pass | BUG | BUG | pass | pass | Strip a string with single quotes, double quoted, with unescaped ' |
| | details | details | | | |
| 28 | pass | BUG | BUG | pass | pass | The string to strip can be single quoted, outer is double quoted |
| | details | details | | | |