diff(a, b) compares two multi-line strings and returns
[markedA, markedB] where each line is prefixed with ' ' (equal)
or '->' at the first divergence. Non-string or single-line inputs
are returned unchanged. Used by pota/use/test to
display assertion failures. Part of pota/use/string.
| Argument | Type | Description |
|---|---|---|
a |
unknown |
The first value to compare. |
b |
unknown |
The second value to compare. |
Returns: [markedA, markedB]. The marking only happens when both
a and b are strings that each contain a newline; only the first
diverging line is flagged with '->', every other line gets the
' ' prefix. Each compared line is run through
toString before marking. Any other input
(non-string, or single-line) is returned as [a, b] untouched.