Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix(flags): False positive when variant rule is an async function #876

Open
wants to merge 4 commits into
base: main
Choose a base branch
from
Open

Fix(flags): False positive when variant rule is an async function #876

Changes from 3 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
0e88606
fix: await rule result if needed
vitoUwu Dec 8, 2024
99228f2
feat: try catch to avoid throwing errors
vitoUwu Dec 8, 2024
9059b24
refactor: skip variants that doesnt have rule as a function
vitoUwu Dec 8, 2024
7890b78
refactor: let it throw
vitoUwu Dec 12, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
36 changes: 29 additions & 7 deletions blocks/flag.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ import JsonViewer from "../components/JsonViewer.tsx";
import type { Block, BlockModule, InstanceOf } from "../engine/block.ts";
import { isDeferred } from "../engine/core/resolver.ts";
import { type Device, deviceOf } from "../utils/userAgent.ts";
import { isAwaitable } from "../utils/mod.ts";
export type Flag = InstanceOf<typeof flagBlock, "#/root/flags">;

export interface FlagObj<TVariant = unknown> {
Expand Down Expand Up @@ -64,7 +65,7 @@ const flagBlock: Block<BlockModule<FlagFunc>> = {
>(func: {
default: FlagFunc<TConfig>;
}) =>
($live: TConfig, { request }: HttpContext) => {
async ($live: TConfig, { request }: HttpContext) => {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

this will impact tracings as only async functions are included on tracing. This shouldn't be though but we should keep an eye on it.

const flag = func.default($live);
let device: Device | null = null;
const ctx = {
Expand All @@ -75,12 +76,33 @@ const flagBlock: Block<BlockModule<FlagFunc>> = {
},
};
if (isMultivariate(flag)) {
const value = ((flag?.variants ?? []).find((variant) =>
typeof variant?.rule === "function" && variant?.rule(ctx)
) as Variant<unknown>)?.value ??
((flag?.variants ?? [])[flag?.variants?.length - 1] as Variant<unknown>)
?.value;
return isDeferred(value) ? value() : value;
let match: Variant<unknown> | null = null;

for (const variant of flag.variants || []) {
if (typeof variant?.rule !== "function") {
continue;
}
let ruleResult = variant?.rule(ctx);
// the rule can sometimes be a promise and we need to await it to check if it's truthy or not
if (isAwaitable(ruleResult)) {
try {
ruleResult = await ruleResult;
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

in the case you provided (when site.ts has an app middleware) this code runs on serial (one await for each matcher) instead of parallel since all matchers will returns a promise, right? Given that, you should instead, parallelize the rule evaluation.

Copy link
Contributor Author

@vitoUwu vitoUwu Dec 12, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

not at all, matchers coming from "website" app continue as sync functions, but my local ones, that depends on my async middleware, turns into async function

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I mean, anyways introducing a middleware will cause all your matchers to be async, so it worth to make parallel instead, wdyt?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

make sense, your proposal is to always use Promise.all on this list, right?

Promise.all(flags.variants.map((variant) => variant.rule(ctx)).find((result) => result)

} catch (_) {
// if the rule throws an error, we don't match this variant
vitoUwu marked this conversation as resolved.
Show resolved Hide resolved
ruleResult = false;
}
}
if (ruleResult) {
match = variant;
break;
}
}

if (!match) {
match = flag.variants[flag.variants.length - 1];
}

return isDeferred(match?.value) ? match?.value() : match?.value;
}
const matchValue = typeof flag?.matcher === "function"
? flag.matcher(ctx)
Expand Down
Loading