Do not throw if a progress is less than last value (#9)

index.d.ts

@@ -762,7 +762,8 @@ declare class PProgress<ValueType> extends Promise<ValueType> {
 		/**
 		@param progress - Call this with progress updates. It expects a number between 0 and 1.
 
-		Multiple calls with the same number will result in only one `onProgress()` event.
+		Multiple calls with the same number will result in only one `onProgress()`
+		event. Calling with a number lower than previously will be ignored.
 
 		Progress percentage `1` is reported for you when the promise resolves. If you set it yourself, it will simply be ignored.
 		*/

index.js

@@ -75,14 +75,13 @@ class PProgress extends Promise {
 				// We wait for the next microtask tick so `super` is called before we use `this`
 				await Promise.resolve();
 
-				if (progress === this._progress) {
+				// Note: we don't really have guarantees over
+				// the order in which async operations are evaluated,
+				// so if we get an out-of-order progress, we'll just discard it.
+				if (progress <= this._progress) {
 					return;
 				}
 
-				if (progress < this._progress) {
-					throw new Error('The progress percentage can\'t be lower than the last progress event');
-				}
-
 				this._progress = progress;
 
 				for (const listener of this._listeners) {

readme.md

@@ -57,7 +57,8 @@ Type: `Function`
 
 Call this with progress updates. It expects a number between 0 and 1.
 
-Multiple calls with the same number will result in only one `onProgress()` event.
+Multiple calls with the same number will result in only one `onProgress()`
+event. Calling with a number lower than previously will be ignored.
 
 Progress percentage `1` is reported for you when the promise resolves. If you set it yourself, it will simply be ignored.