Add support for cache: false to Custom compileOptions. Also informs dynamic import of JavaScript files. Fixes #3737

Author: zachleat

src/Engines/Custom.js

@@ -17,7 +17,7 @@ export default class CustomEngine extends TemplateEngine {
 		this._defaultEngine = undefined;
 
 		// Enable cacheability for this template
-		if (this.entry?.compileOptions?.cache) {
+		if (this.entry?.compileOptions?.cache !== undefined) {
 			this.cacheable = this.entry.compileOptions.cache;
 		} else if (this.needsToReadFileContents()) {
 			this.cacheable = true;

src/Engines/JavaScript.js

@@ -92,8 +92,9 @@ export default class JavaScript extends TemplateEngine {
 			mod = this.eleventyConfig.userConfig.virtualTemplates[relativeInputPath].content;
 		} else {
 			let isEsm = this.eleventyConfig.getIsProjectUsingEsm();
+			let cacheBust = !this.cacheable || !this.config.useTemplateCache;
 			mod = await EleventyImport(inputPath, isEsm ? "esm" : "cjs", {
-				cacheBust: !this.config.useTemplateCache,
+				cacheBust,
 			});
 		}