Chart.js: BUG - src/platforms/platform.dom.js does not support decimals in px

[qsbpetf]

Width or height in pixels can be decimal, e.g. 1163.34px and must be supported which this lib does not support.

Expected Behavior

1163.34px should return 1163

Current Behavior

It returns 34, e.g. only the fractional part. This is due to an error in the regexp.

Possible Solution

Line 36 in src/platforms/platform.dom.js needs to be changed from:
var matches = value && value.match(/(\d+)px/);
into:
var matches = value && value.match(/(\d+)(.\d+)?px/);

Steps to Reproduce (for bugs)

Just use a browser Chrome and do some resizing of the screen.

Context

The diagram sometimes get 10000 px height when 1000px width while it should be 300px height. This is due du aspect ratio in combination with reading only fractional part of px value.

Environment

• Chart.js version: 2.4.0
• Browser name and version: Chrome 55.0.2883.95 (64-bit)

[simonbrunel]

Nice catch @qsbpetf. I think we can make the regexp even more accurate: /^(\d+)(?:\.\d+)?px$/ (we explicitly want a . (dot) as separator (so need to be escaped) and it should start by a number ^ and ends by px$/. I don't know what the browser returns in case of a floating number between 0 and 1: '0.42px' or '.42px' (this regexp only matches the first version).

[qsbpetf]

I fully agree.
When I patched the lib locally I had the escape \ before the dot :) Must have missed it during the writing of this bug.
Thanks for an awesome lib!

[etimberg]

@qsbpetf is it possible to PR a fix for this?

[qsbpetf]

@etimberg I didn't fork the code from GH nor built it. I just DLed the full .js file, single step debugged it in the browser, patched the. js file and then ran it successfully :)

[simonbrunel]

@etimberg I will submit a PR, thanks @qsbpetf for the report :)