async function mergeRootLGFile()

in experimental/generation/generator/packages/library/src/mergeAssets.ts [219:285]
59 lines of code
18 McCabe index (conditional complexity)

async function mergeRootLGFile(schemaName: string, oldPath: string, oldFileList: string[], newPath: string, newFileList: string[], mergedPath: string, locale: string, oldPropertySet: Set<string>, newPropertySet: Set<string>, feedback: Feedback): Promise<void> {
    const outDir = assetDirectory('.lg')
    const oldText = await fs.readFile(ppath.join(oldPath, outDir, locale, `${schemaName}.${locale}${'.lg'}`), 'utf8')
    const oldRefs = oldText.split(os.EOL)
    const newText = await fs.readFile(ppath.join(newPath, outDir, locale, `${schemaName}.${locale}${'.lg'}`), 'utf8')
    const newRefs = newText.split(os.EOL)

    const resultRefs: string[] = []
    const oldRefSet = new Set<string>()

    for (const ref of oldRefs) {
        if (ref.match('> Generator:')) {
            if (resultRefs.length !== 0 && resultRefs[resultRefs.length - 1] === '') {
                resultRefs.pop()
            }
            break
        }
        if (!ref.startsWith('[')) {
            resultRefs.push(ref)
            continue
        }
        oldRefSet.add(ref)
        const file = refFilename(ref, feedback)
        const extractedProperty = extractProperty(file, oldPropertySet, schemaName)
        if (extractedProperty !== undefined) {
            if (newPropertySet.has(extractedProperty)) {
                resultRefs.push(ref)
                if (file.match(`${extractedProperty}Value`)) {
                    await changeEntityEnumLG(oldPath, oldFileList, newPath, newFileList, mergedPath, file, feedback)
                } else {
                    if (await !isOldUnchanged(oldFileList, file) && await getHashCodeFromFile(oldFileList, file) !== await getHashCodeFromFile(newFileList, file)) {
                        cannotMergeMessage(file, oldFileList, newFileList, feedback)
                    } else {
                        await copySingleFile(oldPath, mergedPath, file, oldFileList, feedback)
                    }
                }
            }
        } else {
            resultRefs.push(ref)
            if (newText.match(file) && !await isOldUnchanged(oldFileList, file) && await getHashCodeFromFile(oldFileList, file) !== await getHashCodeFromFile(newFileList, file)) {
                cannotMergeMessage(file, oldFileList, newFileList, feedback)
            } else {
                await copySingleFile(oldPath, mergedPath, file, oldFileList, feedback)
            }
        }
    }

    for (const ref of newRefs) {
        if (!ref.startsWith('[')) {
            continue
        }
        if (!oldRefSet.has(ref)) {
            resultRefs.push(ref)
            const file = refFilename(ref, feedback)
            await copySingleFile(newPath, mergedPath, file, newFileList, feedback)
        }
    }

    let val = resultRefs.join(os.EOL)

    const patternIndex = oldText.search(GeneratorPattern)
    if (patternIndex !== -1) {
        val = val + os.EOL + oldText.substring(patternIndex)
    }

    await writeToFile(oldPath, mergedPath, `${schemaName}.${locale}.lg`, oldFileList, val, feedback)
}