diff --git a/src/index.ts b/src/index.ts
index 7dba246..ab83f80 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,19 +1,26 @@
 import Path from "node:path";
 import { parseArgs } from "node:util";
 import EMDY from "@endeavorance/emdy";
-import defaultStylesheet from "./defaults/default-style.css" with {
+import type { BunFile } from "bun";
+import DEFAULT_STYLESHEET from "./defaults/default-style.css" with {
   type: "text",
 };
-import defaultTemplate from "./defaults/default-template.html" with {
+import DEFAULT_TEMPLATE from "./defaults/default-template.html" with {
   type: "text",
 };
 import { CLIError } from "./error";
-import type { BunFile } from "bun";
 import { parseMarkdown } from "./markdown";
 
 const DEFAULT_TEMPLATE_FILE = "_template.html";
 const DEFAULT_STYLESHEET_FILE = "_style.css";
 
+/**
+ * Given a file path, attempt to read the text of the file
+ * @param filePath - The path to the file to read
+ * @returns The text content of the file
+ *
+ * @throws CLIError if the file does not exist
+ */
 async function readFile(filePath: string): Promise<string> {
   const file = Bun.file(filePath);
   const exists = await file.exists();
@@ -23,7 +30,13 @@ async function readFile(filePath: string): Promise<string> {
   return file.text();
 }
 
-function replacePlaceholders(
+/**
+ * Renders the provided template with the given data.
+ * @param template - The template string containing placeholders like %key%
+ * @param data - An object containing key-value pairs to replace in the template
+ * @returns The rendered string with all placeholders replaced by their corresponding values
+ */
+function renderTemplate(
   template: string,
   data: Record<string, unknown>,
 ): string {
@@ -34,17 +47,39 @@ function replacePlaceholders(
   return output;
 }
 
+/**
+ * A collection of options parsed from the command line arguments.
+ */
 interface CLIOptions {
+  /** A path to the output file */
   outfile: string | null;
+
+  /** A path to the output directory */
   outdir: string | null;
+
+  /** If true, force output to stdout */
   stdout: boolean;
+
+  /** The path to the template file */
   templateFilePath: string | null;
+
+  /** The path to the stylesheet file */
   stylesheetFilePath: string | null;
+
+  /** If true, show help message */
   help: boolean;
+
+  /** If provided, overrides the document title */
   title: string | null;
+
+  /** If provided, overrides the current working directory (default: .) */
   cwd: string;
 }
 
+/**
+ * Parse the command line arguments and return the options and positional arguments.
+ * @returns An object containing the parsed options and positional arguments
+ */
 function parseCLIArgs(): { options: CLIOptions; args: string[] } {
   const { values: flags, positionals } = parseArgs({
     args: Bun.argv.slice(2),
@@ -109,57 +144,69 @@ function parseCLIArgs(): { options: CLIOptions; args: string[] } {
   };
 }
 
+/**
+ * Attempt to load a custom template, falling back to a default
+ * @param options - The CLI options containing the template file path
+ * @returns The template string
+ */
 async function loadTemplate(options: CLIOptions): Promise<string> {
   if (options.templateFilePath) {
     return readFile(options.templateFilePath);
   }
 
-  const defaultTemplateFilePath = Path.join(options.cwd, DEFAULT_TEMPLATE_FILE);
-  const defaultTemplateFile = Bun.file(defaultTemplateFilePath);
+  const checkTemplateFile = Bun.file(
+    Path.join(options.cwd, DEFAULT_TEMPLATE_FILE),
+  );
 
-  if (await defaultTemplateFile.exists()) {
-    return defaultTemplateFile.text();
+  if (await checkTemplateFile.exists()) {
+    return checkTemplateFile.text();
   }
 
-  return defaultTemplate;
+  return DEFAULT_TEMPLATE;
 }
 
+/**
+ * Attempt to load a custom stylesheet, falling back to a default
+ * @param options - The CLI options containing the stylesheet file path
+ * @returns The stylesheet string
+ */
 async function loadStylesheet(options: CLIOptions): Promise<string> {
   if (options.stylesheetFilePath) {
     return readFile(options.stylesheetFilePath);
   }
 
-  const defaultStylesheetFilePath = Path.join(
-    options.cwd,
-    DEFAULT_STYLESHEET_FILE,
+  const checkStylesheetFile = Bun.file(
+    Path.join(options.cwd, DEFAULT_STYLESHEET_FILE),
   );
-  const defaultStylesheetFile = Bun.file(defaultStylesheetFilePath);
 
-  if (await defaultStylesheetFile.exists()) {
-    return defaultStylesheetFile.text();
+  if (await checkStylesheetFile.exists()) {
+    return checkStylesheetFile.text();
   }
 
-  return defaultStylesheet;
+  return DEFAULT_STYLESHEET;
 }
 
+/**
+ * Build and write a file
+ * @param infile - The input file to read from
+ * @param outfile - The output file to write to
+ * @param options - The CLI options containing template and stylesheet paths
+ */
 async function buildFile(
   infile: BunFile,
   outfile: BunFile,
   options: CLIOptions,
-): Promise<string> {
+): Promise<void> {
   const input = await infile.text();
   const template = await loadTemplate(options);
   const stylesheet = await loadStylesheet(options);
-
   const { content, ...props } = EMDY.parse(input) as Record<string, unknown> & {
     content: string;
   };
 
   const html = await parseMarkdown(content);
-
-  const title = [options.title, props.title].find((t) => t) || "Untitled";
-
-  const replacers = {
+  const title = options.title ?? props.title ?? "Untitled";
+  const templateData = {
     content: html,
     title,
     stylesheet: stylesheet,
@@ -168,13 +215,15 @@ async function buildFile(
     ...props,
   };
 
-  const output = replacePlaceholders(template, replacers);
-
-  Bun.write(outfile, output);
-
-  return output;
+  await Bun.write(outfile, renderTemplate(template, templateData));
 }
 
+/**
+ * Get the output path based on the input path and options
+ * @param inputPath - The path of the input file
+ * @param options - The CLI options containing output directory
+ * @returns The resolved output path
+ */
 async function getOutputPath(inputPath: string, options: CLIOptions) {
   const inputDirname = Path.dirname(inputPath);
   const inputBasename = Path.basename(inputPath);
@@ -189,6 +238,12 @@ async function getOutputPath(inputPath: string, options: CLIOptions) {
   return Path.join(inputDirname, outputBasename);
 }
 
+/**
+ * Get the output file based on the input path and options
+ * @param inputPath - The path of the input file
+ * @param options - The CLI options containing output file and directory
+ * @returns The BunFile object representing the output file
+ */
 async function getOutputFile(
   inputPath: string,
   options: CLIOptions,