Function normalizeTemplateFilePath

src/engine/TemplateEngine.ts:529–574

(
		folderPath: string,
		fileName: string,
		templatePath: string
	)

	}

	protected normalizeTemplateFilePath(
		folderPath: string,
		fileName: string,
		templatePath: string
	): string {
		const safeFolderPath = this.stripLeadingSlash(folderPath);
		const actualFolderPath: string = safeFolderPath ? `${safeFolderPath}/` : "";
		const extension = this.getTemplateExtension(templatePath);
		const normalizedFileName = normalizeGeneratedFilePath(
			this.stripLeadingSlash(fileName),
			"File name",
		);
		const formattedFileName: string = normalizeGeneratedFilePath(
			normalizedFileName
				.replace(MARKDOWN_FILE_EXTENSION_REGEX, "")
				.replace(CANVAS_FILE_EXTENSION_REGEX, "")
				.replace(BASE_FILE_EXTENSION_REGEX, ""),
			"File name",
		);
		// Validate the final path segment, not just the whole string — a
		// trailing-slash name like "Projects/" (optional leaf token left
		// empty) would otherwise still produce "Projects/.md".
		const baseName = formattedFileName.slice(
			formattedFileName.lastIndexOf("/") + 1
		);
		if (!baseName.trim()) {
			throw new Error(
				"File name is empty after formatting. Make sure the tokens in the file name format produce a value (an optional token left empty can cause this)."
			);
		}
		const assembledPath = `${actualFolderPath}${formattedFileName}${extension}`;
		// Contain the assembled target at this shared chokepoint. The file NAME is run
		// through normalizeGeneratedFilePath above, but the FOLDER portion is only
		// stripLeadingSlash'd — so a folder like "../../../evil" (from an untrusted,
		// synced Template choice resolved via formatFolderPath) would assemble an
		// out-of-vault path. Both callers act on it without a sink guard: the relocation
		// flow (computeChoiceTargetPath -> createFolder + fileManager.renameFile) would
		// otherwise move the active note OUTSIDE the vault. Reject any escape here so
		// every caller of this assembler is contained.
		if (escapesVaultBoundary(assembledPath)) {
			throw new Error(
				`Refusing to build a file path outside the vault: "${assembledPath}".`,
			);
		}
		return assembledPath;
	}

	protected async createFileWithTemplate(
		filePath: string,