Mathjs: Median hangs if values are NaN

[gnobre]

Median doesn't ever return in some cases containing NaN values, handing the process indefinitely

Hangs:

• mathjs.median(NaN, NaN, NaN)
• mathjs.median(2, NaN, NaN)

Returns NaN

• mathjs.median(2, NaN)
• mathjs.median(NaN)

I would expect all these cases to return NaN, or even something else but not to hang the javascript process.

[josdejong]

Thanks for reporting this bug! We'll fix it asap.

[josdejong]

@gnobre this issue should be solved now in [email protected]. Turns out there was an issue in sorting an array containing numbers including NaN: since both 2 > NaN and NaN > 2 returns false, the sorthing mechanism (inside the function partitionSelect) could get stuck in an infinite loop.

I've added tests for NaN in all statistics functions, see commit.

@harrysarson I was really happy (again) with our testing on travis: turns out assert.strictEqual(NaN, NaN) doesn't work property on older node.js versions (6 and 8), and maybe also not in browsers. :+1:

[gnobre]

@josdejong thanks for resolving this so quick, this was a really tricky one indeed!

[harrysarson]

The new tests are nice aswell :+1: