TL;DR: the rest of the PR prevents the code from ever trying to load snow, so we don't need to copy an empty file anymore.

Dear reviewer: does the addition of --snow=false seem appropriate here?

Dear reviewer: does the addition of --snow=false seem appropriate here?

@zone-live

Note to reviewers:

I did not add --snow=false to the build:test:dev:mv3 script because I don't understand that script. It sets the task/buildTarget to testDev and sets --apply-lavamoat=false, but the MV3 build system running with the TEST_DEV buildTarget forces lavamoat anyway (but in "stats mode").

see (where buildTarget === testDev):

0. metamask-extension/development/build/constants.js

   Line 12 in f2be12c

   TEST_DEV: 'testDev',

1. metamask-extension/development/build/utils.js

   Lines 28 to 38 in f2be12c

   	/**
   	* Returns whether the current build is an e2e test build or not.
   	*
   	* @param {BUILD_TARGETS} buildTarget - The current build target.
   	* @returns Whether the current build is an e2e test build.
   	*/
   	function isTestBuild(buildTarget) {
   	return (
   	buildTarget === BUILD_TARGETS.TEST || buildTarget === BUILD_TARGETS.TEST_DEV
   	);
   	}

2. metamask-extension/development/build/scripts.js

   Lines 1175 to 1178 in f2be12c

   	const testing = isTestBuild(buildTarget);
   	variables.set({
   	IN_TEST: testing,

3. metamask-extension/app/scripts/app-init.js

   Line 8 in f2be12c

   const testMode = process.env.IN_TEST;

4. metamask-extension/app/scripts/app-init.js

   Lines 71 to 76 in f2be12c

   	// Always apply LavaMoat in e2e test builds, so that we can capture initialization stats
   	if (testMode || applyLavaMoat) {
   	loadFile('./runtime-lavamoat.js');
   	loadFile('./lockdown-more.js');
   	loadFile('./policy-load.js');
   	} else {

5. metamask-extension/development/build/scripts.js

   Lines 541 to 547 in f2be12c

   	// Code below is used to set statsMode to true when testing in MV3
   	// This is used to capture module initialisation stats using lavamoat.
   	if (isTestBuild(buildTarget)) {
   	const content = readFileSync('./dist/chrome/runtime-lavamoat.js', 'utf8');
   	const fileOutput = content.replace('statsMode = false', 'statsMode = true');
   	writeFileSync('./dist/chrome/runtime-lavamoat.js', fileOutput);
   	}

It actually more like a start: script than a build: script, so that makes it even more confusing.

Since this isn't used in CI I stopped investigating why it is the way it is and am writing this comment instead.