Function postProcessFrontMatter

src/engine/helpers/frontmatterPostProcessor.ts:188–241

(
	app: App,
	file: TFile,
	templatePropertyVars: Map<string, unknown>,
)

 *   (see coerceYamlValue in utils/yamlValues.ts for implementation details)
 */
export async function postProcessFrontMatter(
	app: App,
	file: TFile,
	templatePropertyVars: Map<string, unknown>,
): Promise<void> {
	// Validate structured variables before processing
	const validation = validateStructuredVariables(templatePropertyVars);

	// Log any validation warnings
	if (validation.warnings.length > 0) {
		for (const warning of validation.warnings) {
			log.logWarning(`Structured variable validation warning: ${warning}`);
		}
	}

	// If validation found errors, log them and skip post-processing
	if (!validation.isValid) {
		const errorSummary = validation.errors.join("; ");
		log.logError(
			`Cannot post-process front matter for file ${file.path} due to validation errors: ${errorSummary}. ` +
			`The file was created successfully, but some structured variables may not be properly formatted. ` +
			`Please check the variable values and ensure they don't contain circular references, ` +
			`exceed nesting depth of ${VALIDATION_LIMITS.MAX_NESTING_DEPTH}, or contain unsupported types (functions, symbols).`
		);
		return;
	}

	try {
		log.logMessage(`Post-processing front matter for ${file.path} with ${templatePropertyVars.size} structured variables`);
		log.logMessage(`Variable types: ${Array.from(templatePropertyVars.entries())
			.map(([k, v]) => `${k}:${typeof v}`).join(', ')}`);

		await app.fileManager.processFrontMatter(file, (frontmatter) => {
			for (const [key, value] of templatePropertyVars) {
				const pathSegments = key.includes(TemplatePropertyCollector.PATH_SEPARATOR)
					? key.split(TemplatePropertyCollector.PATH_SEPARATOR)
					: [key];
				const coerced = coerceYamlValue(value);
				assignFrontmatterValue(frontmatter, pathSegments, coerced);
			}
		});

		log.logMessage(`Successfully post-processed front matter for ${file.path}`);
	} catch (err) {
		// Improved error message with actionable information
		log.logError(
			`Failed to post-process front matter for file ${file.path}: ${err}. ` +
			`The file was created successfully, but structured variables may not be properly formatted. ` +
			`This usually happens when variable values contain unexpected types or when Obsidian's YAML processor encounters an issue. ` +
			`Check the console for more details about which variables caused the problem.`
		);
		// Don't throw - the file was still created successfully
	}
}

/**
 * Key segments that become a prototype-pollution gadget only when a value is