chore: add exhaustiveness error utility #478
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We have a few exhaustiveness checks. I think it's time to DRY these out into a simple utility function. (I plan to use this in an upcoming change, which is why I'm doing this now.)
tests/utils.js
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| test('exhaustivenessError', () => { | ||
| const bools = [true, false] | ||
| bools.forEach((bool) => { | ||
| switch (bool) { | ||
| case true: | ||
| case false: | ||
| break | ||
| default: | ||
| throw exhaustivenessError(bool) | ||
| } | ||
| }) | ||
| }) |
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This test doesn't have any assertions (it just makes sure things don't throw unexpectedly). Not sure if there's a cleaner way to test this.
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Thanks! Done in c83a120.
src/utils.js
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| export const exhaustivenessError = (value) => | ||
| new Error(`Exhaustiveness check failed. ${value} should be impossible`) |
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thoughts on an implementation that extends Error instead? e.g.
class ExhaustivenessError extends Error {
constructor(value) {
super(`Exhaustiveness check failed. ${value} should be impossible`)
this.name = 'ExhaustivenessError'
}
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I think I prefer that. Done in e088115.
tests/utils.js
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| test('exhaustivenessError', () => { | ||
| const bools = [true, false] | ||
| bools.forEach((bool) => { | ||
| switch (bool) { | ||
| case true: | ||
| case false: | ||
| break | ||
| default: | ||
| throw exhaustivenessError(bool) | ||
| } | ||
| }) | ||
| }) |
|
The purpose of these exhaustiveness checks is to get a typescript error if we are not checking all the options. Does this achieve the same thing? |
|
If it does then this looks good to me. |
Yup! Exact same thing. |
EvanHahn
changed the title
We have a few exhaustiveness checks. I think it's time to DRY these out into a simple utility function.
(I plan to use this in an upcoming change, which is why I'm doing this now.)