Faster emojify() algorithm, avoid regex replace (#4019)

* Faster emojify() algorithm, avoid regex replace

* add semicolon
main
Nolan Lawson 7 years ago committed by Eugen Rochko
parent 6dd5eac7fc
commit a978b88997

@ -19,16 +19,41 @@ const unicodeToImage = str => {
});
};
const shortnameToImage = str => str.replace(emojione.regShortNames, shortname => {
if (typeof shortname === 'undefined' || shortname === '' || !(shortname in emojione.emojioneList)) {
return shortname;
}
const shortnameToImage = str => {
// This walks through the string from end to start, ignoring any tags (<p>, <br>, etc.)
// and replacing valid shortnames like :smile: and :wink: that _aren't_ within
// tags with an <img> version.
// The goal is to be the same as an emojione.regShortNames replacement, but faster.
// The reason we go backwards is because then we can replace substrings as we go.
let i = str.length;
let insideTag = false;
let insideShortname = false;
let shortnameEndIndex = -1;
while (i--) {
const char = str.charAt(i);
if (insideShortname && char === ':') {
const shortname = str.substring(i, shortnameEndIndex + 1);
if (shortname in emojione.emojioneList) {
const unicode = emojione.emojioneList[shortname].unicode[emojione.emojioneList[shortname].unicode.length - 1];
const alt = emojione.convert(unicode.toUpperCase());
return `<img draggable="false" class="emojione" alt="${alt}" title="${shortname}" src="/emoji/${unicode}.svg" />`;
});
const replacement = `<img draggable="false" class="emojione" alt="${alt}" title="${shortname}" src="/emoji/${unicode}.svg" />`;
str = str.substring(0, i) + replacement + str.substring(shortnameEndIndex + 1);
} else {
i++; // stray colon, try again
}
insideShortname = false;
} else if (insideTag && char === '<') {
insideTag = false;
} else if (char === '>') {
insideTag = true;
insideShortname = false;
} else if (!insideTag && char === ':') {
insideShortname = true;
shortnameEndIndex = i;
}
}
return str;
};
export default function emojify(text) {
return toImage(text);

@ -0,0 +1,49 @@
import { expect } from 'chai';
import emojify from '../../../app/javascript/mastodon/emoji';
describe('emojify', () => {
it('does a basic emojify', () => {
expect(emojify(':smile:')).to.equal(
'<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" />');
});
it('does a double emojify', () => {
expect(emojify(':smile: and :wink:')).to.equal(
'<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" /> and <img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" />');
});
it('works with random colons', () => {
expect(emojify(':smile: : :wink:')).to.equal(
'<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" /> : <img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" />');
expect(emojify(':smile::::wink:')).to.equal(
'<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" />::<img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" />');
expect(emojify(':smile:::::wink:')).to.equal(
'<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" />:::<img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" />');
});
it('works with tags', () => {
expect(emojify('<p>:smile:</p>')).to.equal(
'<p><img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" /></p>');
expect(emojify('<p>:smile:</p> and <p>:wink:</p>')).to.equal(
'<p><img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" /></p> and <p><img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" /></p>');
});
it('ignores unknown shortcodes', () => {
expect(emojify(':foobarbazfake:')).to.equal(':foobarbazfake:');
});
it('ignores shortcodes inside of tags', () => {
expect(emojify('<p data-foo=":smile:"></p>')).to.equal('<p data-foo=":smile:"></p>');
});
it('works with unclosed tags', () => {
expect(emojify('hello>')).to.equal('hello>');
expect(emojify('<hello')).to.equal('<hello');
});
it('works with unclosed shortcodes', () => {
expect(emojify('smile:')).to.equal('smile:');
expect(emojify(':smile')).to.equal(':smile');
});
});
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