convert/normalize special characters when using jspdf

Trying to use the jspdf lib @1.4.1 to convert text to pdf, the output sometimes gets so ugly and unreadable, because the text contains some special characters, like:

the left single quotation mark U+2018, or the right one U+2019, or symbols like →, or the ı in Kadıköy... how can i sanitize/normalize such texts? or is there any option is jspdf that i can use to fix this problem?

update:

to reproduce the problem, just use this string: '→Kadıköy' in this example https://parall.ax/products/jspdf , line 9, you will see that the arrow is converted to !’ and the ı is converted to 1

(FYI, Kadıköy is name of a city https://en.wikipedia.org/wiki/Kad%C4%B1k%C3%B6y)

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