web/scripts/i18n/syncDefaultMessage/syncIntlFormatMessage.ts

export function syncIntlFormatMessage({
    translations,
    fileContent,
}: {
    translations: Record<string, string>;
    fileContent: string;
}): { updated: boolean; fileContent: string } {
    let updated = false;
    const entries = Object.entries(translations);

    for (const [messageId, messageValue] of entries) {
        const escapedId = messageId.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");

        // Find intl.formatMessage({...}) blocks that contain the specific id
        const outerRegex = new RegExp(
            `intl\\.formatMessage\\(\\s*\\{([^}]*?\\bid\\s*:\\s*['"]${escapedId}['"][^}]*?)\\}\\s*\\)`,
            "gs"
        );

        fileContent = fileContent.replace(
            outerRegex,
            (fullMatch, innerObject) => {
                // Find defaultMessage: '...' or "..."
                const dmRegex =
                    /defaultMessage\s*:\s*(['"])((?:\\.|[\s\S])*?)\1/;
                if (!dmRegex.test(innerObject)) return fullMatch;

                const newInner = innerObject.replace(
                    dmRegex,
                    (_m: unknown, quote: string, _old: unknown) => {
                        // Escape backslashes first, then the surrounding quote, and newlines
                        const escaped = messageValue
                            .replace(/\\/g, "\\\\")
                            .replace(new RegExp(quote, "g"), `\\${quote}`)
                            .replace(/\n/g, "\\n");
                        return `defaultMessage: ${quote}${escaped}${quote}`;
                    }
                );

                updated = true;
                return `intl.formatMessage({${newInner}})`;
            }
        );
    }

    return { updated, fileContent };
}