Use the basedir option to resolve the template path

src/pug.coffee

@@ -1,14 +1,20 @@
+import {extname, isAbsolute, join} from "node:path"
 import {compile, compileFile, render, renderFile} from "pug"
 import {htmlToPdf} from "./puppeteer.js"
 
 # Attaches a view renderer to the context of the specified application.
 export pug = (application, rendererOptions = {}) ->
 	renderer = Object.freeze {compile, compileFile, render, renderFile}
 
+	# Resolves the path of the specified view.
+	resolvePath = (view) ->
+		view += ".pug" unless extname view
+		if isAbsolute(view) or not rendererOptions.basedir? then view else join rendererOptions.basedir, view
+
 	# Renders the specified view.
 	_render = (view, locals = {}, renderingOptions = {}) ->
 		data = {rendererOptions..., @state..., locals...}
-		html = await Promise.resolve renderer.renderFile view, data
+		html = await Promise.resolve renderer.renderFile resolvePath(view), data
 		if renderingOptions.writeResponse ? yes
 			@body = html
 			@type = "html"
@@ -17,7 +23,7 @@ export pug = (application, rendererOptions = {}) ->
 	# Renders the specified view as a PDF document.
 	_renderPdf = (view, locals = {}, renderingOptions = {}) ->
 		data = {rendererOptions..., @state..., locals...}
-		html = await Promise.resolve renderer.renderFile view, data
+		html = await Promise.resolve renderer.renderFile resolvePath(view), data
 		pdf = await htmlToPdf html, browser: rendererOptions.browser, pdf: renderingOptions
 		if renderingOptions.writeResponse ? yes
 			@body = pdf