branch.js

branch.js

import isfunction from "./isfunction";
import istruthy from "./istruthy";
import reduce from "./reduce";

¶

This function provides if-elseif-else. branch( test, result_if_true, [test2, result_if_true, default_result] ).
```
export default function branch(...cases) {
  var resolved = false;
```

Reduce all cases into a value.

  return reduce(
    cases,
    function(acc, item, index) {
      let val;

Return previously resolved result.

      if (resolved === true) return acc;

¶

Handle default case.
```
      if (index === cases.length - 1) {
```
¶

There is no last item.
```
        if (index % 2 === 1) return;
```

return the last item.

        return isfunction(item) ? item() : item;
      }

Check if condition is true.

      if (
        index % 2 === 0 &&
        ((isfunction(item) && istruthy(item())) ||
          (!isfunction(item) && istruthy(item)))
      ) {
        resolved = true;
        val = cases[index + 1];
        return isfunction(val) ? val() : val;
      }

      return acc;
    },
    undefined
  );
}