Add toNumber and cleanup toString. Plus a wide range of tests.

[Xotic750]

#1574
#1576 (comment)

[Xotic750]

Ok, something funky with node v0.8, but don't have the time to investigate just now, must sleep and have to take kids to museum tomorrow. Maybe the hex bug that I mentioned in my enhancement post. I'm also unsure if QUnit's deepEqual test for -0

[Xotic750]

That should cover most of the basic use cases, and catch any basic bugs/deficiencies. There are plenty more that could be added to catch other bugs, like I mentioned with Opera where an object has valueOf defined but it's not a function. Other (highly)possible environment deficiencies are regarding whitespace, where the native trim does not trim correctly. Which some could be corrected by if value is string then return +trimmed rather than fall through to return +value. This still leaves return +value coercion open to environment deficiencies.

[Xotic750]

To catch even more string issues, the type value === 'string' could be extended to String objects by using isString(value) instead.

[Xotic750]

Finally (for now), do we keep this early return for number types?

    function toNumber(value) {
      // Possibly not required, not sure if this improves performance or not?
      if (typeof value === 'number') {
        return value;
      }

[Xotic750]

So, node v0.8 has a problem with this case again converting bad hex strings.

[Xotic750]

Now need to find a simple fix without implementing a full toPrimitive shim, if possible.

[jdalton]

Shouldn't bad hex fall out naturally as NaN from the +trimmed below?

[Xotic750]

I will look at improving the flow.

[jdalton]

Can you rebase this PR.

[Xotic750]

I've created a (more) optimised version (I think a little more could be done), instead of calling lodash methods. I don't know if you'd prefer this instead, as it looks like I need to rebase again?

    function toNumber(value) {
      if (value != null) {
        var type = typeof value;
        if (type == 'number') {
          return value;
        }
        if (value) {
          var tagString = objToString.call(value);
          if (tagString != numberTag) {
            if (tagString == stringTag) {
              value += '';
            } else {
              if ((type == 'object' || type == 'function') && isFunction(value.valueOf)) {
                value = value.valueOf.call(value);
                type = typeof value;
                if (type == 'number') {
                  return value;
                }
              }
              if (value && (type == 'object' || type == 'function')) {
                value = toString(value);
              }
            }
            if (value && typeof value == 'string') {
              value = trim(value);
              if (value) {
                var isBinary = reIsBinary.test(value);
                if (isBinary || reIsOctal.test(value)) {
                  return nativeParseInt(value.slice(2), isBinary ? 2 : 8);
                }
                if (reIsBadHex.test(value)) {
                  return NaN;
                }
              }
            }
          }
        }
      }
      return +value;
    }

[jdalton]

Not a fan of that. Less is more.

[jdalton]

This can be simplified:

function toNumber(value) {
  var result = +value;
  if (typeof value == 'number' || result === result) {
    return result;
  }
  value = trim(value);
  var isBinary = reIsBinary.test(value);
  return (isBinary || reIsOctal.test(value))
    ? nativeParseInt(value.slice(2), isBinary ? 2 : 8)
    : result;
}

[Xotic750]

That is going to fail on at least node v0.8 I believe. But that should just be a case of adding the bad hex test back in. It's nice to see where your experience pays off wrt simplification. Let me change it and we can see.

[jdalton]

Ah cool, verified 0.8 does not return NaN :P

[Xotic750]

Ok, I'll just rebase it.

[Xotic750]

I don't know if it is just me, but git doesn't seem very good at auto merging simple upstream changes? I seem to need to do a fair amount of manual merging each time. And it always worries me that I may get it wrong. :)

[jdalton]

It'll be easier in your branch to copy the lodash.js and test.js to another location then.

git reset --hard c142cfc81dce4c3cbd3ff4ceb33e13df13062be9
# add your lodash.js and test.js back
git add -u
git commit -m "Add _.isNumber."
git push origin +master

[Xotic750]

I guess I'll get better at it, at the end of the day I'm just a self taught enthusiast. ;) Node v0.8 and v0.10 don't seem happy with that new code.

[jdalton]

Closed via 3795534.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.