Revamp (#83)

* See CHANGELOG for v3.0.0

* removed get-stream

* enabled linter just for test.js & from.js

* Any blob part is acceptable (jsdoc)
since the default fallback is to cast unknown items into strings

* async stat version

* import from fs/promise instead

* Updated the Readme and code examples

* known differences, buffer.Blob support, private stream, more test

* require node 14

* use fetch v3

from.js

@@ -1,56 +1,69 @@
-const {statSync, createReadStream} = require('fs');
-const Blob = require('./index.js');
-const DOMException = require('domexception');
+import {statSync, createReadStream} from 'fs';
+import {stat} from 'fs/promises';
+import DOMException from 'domexception';
+import Blob from './index.js';
 
 /**
  * @param {string} path filepath on the disk
  * @returns {Blob}
  */
-function blobFrom(path) {
-	const {size, mtime} = statSync(path);
-	const blob = new BlobDataItem({path, size, mtime});
+ const blobFromSync = path => from(statSync(path), path);
 
-	return new Blob([blob]);
-}
+/**
+ * @param {string} path filepath on the disk
+ * @returns {Promise<Blob>}
+ */
+ const blobFrom = path => stat(path).then(stat => from(stat, path));
+
+const from = (stat, path) => new Blob([new BlobDataItem({
+	path,
+	size: stat.size,
+	lastModified: stat.mtimeMs,
+	start: 0
+})]);
 
 /**
  * This is a blob backed up by a file on the disk
- * with minium requirement
+ * with minium requirement. Its wrapped around a Blob as a blobPart
+ * so you have no direct access to this.
  *
  * @private
  */
 class BlobDataItem {
+	#path;
+	#start;
+
 	constructor(options) {
+		this.#path = options.path;
+		this.#start = options.start;
 		this.size = options.size;
-		this.path = options.path;
-		this.start = options.start || 0;
-		this.mtime = options.mtime;
+		this.lastModified = options.lastModified
 	}
 
-	// Slicing arguments is first validated and formated
-	// to not be out of range by Blob.prototype.slice
+	/**
+	 * Slicing arguments is first validated and formatted
+	 * to not be out of range by Blob.prototype.slice
+	 */
 	slice(start, end) {
 		return new BlobDataItem({
-			path: this.path,
-			start,
-			mtime: this.mtime,
-			size: end - start
+			path: this.#path,
+			lastModified: this.lastModified,
+			size: end - start,
+			start
 		});
 	}
 
-	stream() {
-		if (statSync(this.path).mtime > this.mtime) {
+	async * stream() {
+		const {mtimeMs} = await stat(this.#path)
+		if (mtimeMs > this.lastModified) {
 			throw new DOMException('The requested file could not be read, typically due to permission problems that have occurred after a reference to a file was acquired.', 'NotReadableError');
 		}
-
-		if (!this.size) {
-			return new Blob().stream();
+		if (this.size) {
+			yield * createReadStream(this.#path, {
+				start: this.#start,
+				end: this.#start + this.size - 1
+			});
 		}
-
-		return createReadStream(this.path, {
-			start: this.start,
-			end: this.start + this.size - 1
-		});
 	}
 
 	get [Symbol.toStringTag]() {
@@ -58,4 +71,5 @@ class BlobDataItem {
 	}
 }
 
-module.exports = blobFrom;
+export default blobFromSync;
+export {Blob, blobFrom, blobFromSync};