Function replaceVariables

src/spec-node/dockerfileUtils.ts:158–179

(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, globalBuildxPlatformArgs: Record<string, string> = {}, str: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number)

}

function replaceVariables(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, globalBuildxPlatformArgs: Record<string, string> = {}, str: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number) {			
	return [...str.matchAll(argumentExpression)]
		.map(match => {
			const variable = match.groups!.variable;
			const isVarExp = match.groups!.isVarExp ? true : false;
			let value = findValue(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, variable, stage, beforeInstructionIndex) || '';
			if (isVarExp) {
				// Handle replacing variable expressions (${var:+word}) if they exist
				const option = match.groups!.option;
				const word = match.groups!.word;
				const isSet = value !== '';
				value = getExpressionValue(option, isSet, word, value);
			}

			return {
				begin: match.index!,
				end: match.index! + match[0].length,
				value,
			};
		}).reverse()
		.reduce((str, { begin, end, value }) => str.substring(0, begin) + value + str.substring(end), str);
}

function findValue(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, globalBuildxPlatformArgs: Record<string, string> = {}, variable: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number): string | undefined {
	let considerArg = true;