All: Use Lerna to manage monorepo

packages/lib/mime-utils.js

@@ -0,0 +1,50 @@
+const mimeTypes = require('./mime-utils-types');
+
+const mime = {
+	fromFileExtension(ext) {
+		ext = ext.toLowerCase();
+		for (let i = 0; i < mimeTypes.length; i++) {
+			const t = mimeTypes[i];
+			if (t.e.indexOf(ext) >= 0) {
+				return t.t;
+			}
+		}
+		return null;
+	},
+
+	fromFilename(name) {
+		if (!name) return null;
+		const splitted = name.trim().split('.');
+		if (splitted.length <= 1) return null;
+		return mime.fromFileExtension(splitted[splitted.length - 1]);
+	},
+
+	toFileExtension(mimeType) {
+		mimeType = mimeType.toLowerCase();
+		for (let i = 0; i < mimeTypes.length; i++) {
+			const t = mimeTypes[i];
+			if (mimeType == t.t) {
+				// Return the first file extension that is 3 characters long
+				// If none exist return the first one in the list.
+				for (let j = 0; j < t.e.length; j++) {
+					if (t.e[j].length == 3) return t.e[j];
+				}
+				return t.e[0];
+			}
+		}
+		return null;
+	},
+
+	fromDataUrl(dataUrl) {
+		// Example: data:image/jpeg;base64,/9j/4AAQSkZJR.....
+		const defaultMime = 'text/plain';
+		const p = dataUrl.substr(0, dataUrl.indexOf(',')).split(';');
+		let s = p[0];
+		s = s.split(':');
+		if (s.length <= 1) return defaultMime;
+		s = s[1];
+		return s.indexOf('/') >= 0 ? s : defaultMime; // https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs
+	},
+};
+
+module.exports = { mime };