compile.sh

#!/bin/bash
# safety settings
set -u
set -e
set -o pipefail

function run {
	version="$1"
	if [ "$version" == "" ]; then
		version_spec=""
		version_human="the newest version"
	else
		version_spec="@$version"
		version_human="$version"
	fi

	echo "Running for $version_human"
	npx google-closure-compiler$version_spec \
		-O ADVANCED \
		--language_in=ES_NEXT \
		--module_resolution=NODE \
		--dependency_mode=PRUNE \
		main.js some-module.js \
		--entry_point main.js \
		> opt$version_spec.js
	echo "DONE: opt$version_spec.js  ($version_human)"
}

if [ $# == 0 ]; then
	# Run in the newest version + version currently used in Scala.js
	for version_spec in "" v20220202; do
		run "$version_spec"
	done
else
	# Run in the specified versions
	for version_spec in "$@"; do
		run "$version_spec"
	done
fi

main.js

import * as foo from "./some-module.js";

foo["bar"]();

output.log

4 
~/cloco-imports (1 bg job)% ./compile.sh ""
Running for the newest version
java.lang.NullPointerException: NAME foo 3:0  [length: 3] [source_file: main.js] : Color{id=0, prototypes=[], instanceColors=[], invalidating=true, propertiesKeepOriginalName=false, constructor=false, ownProperties=[], boxId=null, closureAssert=false, unionElements=[]}
	at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:907)
	at com.google.javascript.jscomp.RemoveUnusedCode.getVarForNameNode(RemoveUnusedCode.java:858)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNameNode(RemoveUnusedCode.java:711)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNode(RemoveUnusedCode.java:535)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseChildren(RemoveUnusedCode.java:1262)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNode(RemoveUnusedCode.java:547)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseChildren(RemoveUnusedCode.java:1262)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseCall(RemoveUnusedCode.java:769)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNode(RemoveUnusedCode.java:463)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseChildren(RemoveUnusedCode.java:1262)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNode(RemoveUnusedCode.java:547)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseChildren(RemoveUnusedCode.java:1262)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNode(RemoveUnusedCode.java:547)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseChildren(RemoveUnusedCode.java:1262)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseNode(RemoveUnusedCode.java:547)
	at com.google.javascript.jscomp.RemoveUnusedCode$Continuation.apply(RemoveUnusedCode.java:1776)
	at com.google.javascript.jscomp.RemoveUnusedCode.traverseAndRemoveUnusedReferences(RemoveUnusedCode.java:378)
	at com.google.javascript.jscomp.RemoveUnusedCode.process(RemoveUnusedCode.java:352)
	at com.google.javascript.jscomp.PhaseOptimizer$NamedPass.process(PhaseOptimizer.java:240)
	at com.google.javascript.jscomp.PhaseOptimizer.process(PhaseOptimizer.java:179)
	at com.google.javascript.jscomp.Compiler.performTranspilationAndOptimizations(Compiler.java:2969)
	at com.google.javascript.jscomp.Compiler.lambda$stage2Passes$7(Compiler.java:1031)
	at com.google.javascript.jscomp.CompilerExecutor.lambda$runInCompilerThread$0(CompilerExecutor.java:100)
	at java.base@17.0.7/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base@17.0.7/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base@17.0.7/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base@17.0.7/java.lang.Thread.run(Thread.java:833)
	at org.graalvm.nativeimage.builder/com.oracle.svm.core.thread.PlatformThreads.threadStartRoutine(PlatformThreads.java:775)
	at org.graalvm.nativeimage.builder/com.oracle.svm.core.posix.thread.PosixPlatformThreads.pthreadStartRoutine(PosixPlatformThreads.java:203)

some-module.js

/** @nocompile */
function xxx(){}

/** @type {Object} */
var x;

//export { xxx as bar };
export default x;