ESM Modules: ssrTransform blindly overwrites all functions named as an import instead of checking for a locally scoped function with the same name

[btakita]

Describe the bug

See: sveltejs/kit#1947

ssrTransform replaces all subscribe references defined within writable with __vite_ssr_import_0__.subscribe instead of using the subscribe function defined within writable.

Due to ssrTransform https://github.com/vitejs/vite/blob/main/packages/vite/src/node/ssr/ssrTransform.ts#L189,
writable in store/index.mjs is transpiled to become:

function writable(value, start = __vite_ssr_import_0__.noop) {
    let stop;
    const subscribers = [];
    function set(new_value) {
        if (__vite_ssr_import_0__.safe_not_equal(value, new_value)) {
            value = new_value;
            if (stop) { // store is ready
                const run_queue = !subscriber_queue.length;
                for (let i = 0; i < subscribers.length; i += 1) {
                    const s = subscribers[i];
                    s[1]();
                    subscriber_queue.push(s, value);
                }
                if (run_queue) {
                    for (let i = 0; i < subscriber_queue.length; i += 2) {
                        subscriber_queue[i][0](subscriber_queue[i + 1]);
                    }
                    subscriber_queue.length = 0;
                }
            }
        }
    }
    function update(fn) {
        set(fn(value));
    }
    function subscribe(run, invalidate = __vite_ssr_import_0__.noop) {
        const subscriber = [run, invalidate];
        subscribers.push(subscriber);
        if (subscribers.length === 1) {
            stop = start(set) || __vite_ssr_import_0__.noop;
        }
        run(value);
        return () => {
            const index = subscribers.indexOf(subscriber);
            if (index !== -1) {
                subscribers.splice(index, 1);
            }
            if (subscribers.length === 0) {
                stop();
                stop = null;
            }
        };
    }
    return { set, update, subscribe: __vite_ssr_import_0__.subscribe };
}

Reproduction

https://github.com/btakita/sveltekit-repro-subscribe-issue

svelte.config.js is forced to be an esm module by using a top-level await: https://github.com/btakita/sveltekit-repro-subscribe-issue/blob/main/svelte.config.js#L4

svelte/store writable is transpiled where subscribe is replaced by vite_ssr_import_0.subscribe https://github.com/btakita/sveltekit-repro-subscribe-issue/blob/main/src/hooks/index.ts

System Info

System:
    OS: Linux 5.12 Arch Linux
    CPU: (16) x64 AMD Ryzen 7 5800X 8-Core Processor
    Memory: 33.55 GB / 62.78 GB
    Container: Yes
    Shell: 5.8 - /usr/bin/zsh
  Binaries:
    Node: 16.5.0 - ~/.config/nvm/versions/node/v16.5.0/bin/node
    Yarn: 1.22.10 - /usr/bin/yarn
    npm: 7.19.1 - ~/.config/nvm/versions/node/v16.5.0/bin/npm
  Browsers:
    Brave Browser: 91.1.26.77
    Chromium: 91.0.4472.164

Used Package Manager

npm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/vue-next instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.

[benmccann]

Here's the code in question: https://github.com/sveltejs/svelte/blob/ff6ce725bfdabba908690f4bae0b06a3f26da881/src/runtime/store/index.ts#L91

That gets compiled to store/index.mjs in the Svelte package:

import { noop, safe_not_equal, subscribe, run_all, is_function } from '../internal/index.mjs';

...

/**
 * Create a `Writable` store that allows both updating and reading by subscription.
 * @param {*=}value initial value
 * @param {StartStopNotifier=}start start and stop notifications for subscriptions
 */
function writable(value, start = noop) {
    let stop;
    const subscribers = [];
    function set(new_value) {
        if (safe_not_equal(value, new_value)) {
            value = new_value;
            if (stop) { // store is ready
                const run_queue = !subscriber_queue.length;
                for (let i = 0; i < subscribers.length; i += 1) {
                    const s = subscribers[i];
                    s[1]();
                    subscriber_queue.push(s, value);
                }
                if (run_queue) {
                    for (let i = 0; i < subscriber_queue.length; i += 2) {
                        subscriber_queue[i][0](subscriber_queue[i + 1]);
                    }
                    subscriber_queue.length = 0;
                }
            }
        }
    }
    function update(fn) {
        set(fn(value));
    }
    function subscribe(run, invalidate = noop) {
        const subscriber = [run, invalidate];
        subscribers.push(subscriber);
        if (subscribers.length === 1) {
            stop = start(set) || noop;
        }
        run(value);
        return () => {
            const index = subscribers.indexOf(subscriber);
            if (index !== -1) {
                subscribers.splice(index, 1);
            }
            if (subscribers.length === 0) {
                stop();
                stop = null;
            }
        };
    }
    return { set, update, subscribe };
}

There are two functions named subscribe in this code and it appears ssrTransform doesn't realize that and replaces them both

[Lenard-0]

Getting this issue. store.subscribe is not a function

[AlbertMarashi]

Getting issue as well when running a fork of svelte in my project.