[v3] treeshake unexpectedly assumed "a" in b==b.a != null

[liuxingbaoyu]

Rollup Version

3.2.2

Operating System (or Browser)

all

Node Version (if applicable)

14-18

Link To Reproduction

repl

Expected Behaviour

/* TREE-SHAKING */
import * as virtualTypes from "./virtual-types";

function isVirtualType(type) {
  return type in virtualTypes;
}

function explode(type) {
  if(!(type in virtualTypes))return;

  const types = virtualTypes[type]

  if(virtualTypes[type] != null){
    // here ↑
    for (const type of types) {
      if (visitor[type]) {
        mergePair(visitor[type], fns);
      }
    }
  }
}

var visitors = /*#__PURE__*/Object.freeze({
  __proto__: null,
  explode: explode,
  verify: verify,
  merge: merge
});

Actual Behaviour

'use strict';

const a=[];

var virtualTypes = /*#__PURE__*/Object.freeze({
  __proto__: null,
  a: a
});

/* TREE-SHAKING */

function explode(type) {
  if(!(type in virtualTypes))return;

  const types = virtualTypes[type];

  {
    // here ↑
    for (const type of types) {
      if (visitor[type]) {
        mergePair(visitor[type], fns);
      }
    }
  }
}

/*#__PURE__*/Object.freeze({
  __proto__: null,
  explode: explode,
  verify: verify,
  merge: merge
});

[lukastaegert]

Thanks! Simplified example: https://rollupjs.org/repl/?version=3.2.2&shareable=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

[lukastaegert]

Fix at #4684

https://rollupjs.org/repl/?pr=4684&shareable=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

[liuxingbaoyu]

Thanks!

[rollup-bot]

This issue has been resolved via #4684 as part of rollup@3.2.3. You can test it via npm install rollup.