fix(instrumentor): Do not run the arithmetic operator mutator on obvious string concatenations #2648
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…ous string concatenations
Garethp
commented
Dec 7, 2020
| return false; | ||
| } | ||
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| const stringTypes = ['StringLiteral', 'TemplateLiteral']; |
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On further thought, this should probably be a whitelist not a blacklist. It's a bit weird, but something like:
const log = (thingToLog) => console.log(thingToLog);
const concat = 1 + log;
console.log(concat)
Will result in "1(thingToLog) => console.log(thingToLog)". What do you think @nicojs, should we do a whitelist of things that actually make sense for an ArithmeticOperator, or keep it simple and only make exceptions for strings and template strings?
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I think a whitelist can become big and hard(er) to maintain. I personally think this is fine to start with. It's better than what we have now.
nicojs
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nicojs
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Dec 9, 2020
Don't mutate `"a" + "b"` into `"a" - "b"`. This only works for 'obvious' string concats.
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As discussed in #2646, this is a shallow "Best-effort" approach to not mutating obvious string concatenations