From 5f2dba72774c444538ed10aa5f2096104cb0b4bb Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Thu, 3 Mar 2022 15:58:06 +0800
Subject: [PATCH] feat: new `hasChanged` method (#202)

---
 README.md           |  4 ++++
 index.d.ts          |  5 +++++
 src/MagicString.js  |  4 ++++
 test/MagicString.js | 20 ++++++++++++++++++++
 4 files changed, 33 insertions(+)

diff --git a/README.md b/README.md
index e7e1eef..1f12867 100644
--- a/README.md
+++ b/README.md
@@ -117,6 +117,10 @@ The returned sourcemap has two (non-enumerable) methods attached for convenience
 code += '\n//# sourceMappingURL=' + map.toUrl();
 ```
 
+### s.hasChanged()
+
+Indicates if the string has been changed.
+
 ### s.indent( prefix[, options] )
 
 Prefixes each line of the string with `prefix`. If `prefix` is not supplied, the indentation will be guessed from the original content, falling back to a single tab character. Returns `this`.
diff --git a/index.d.ts b/index.d.ts
index fd62cd8..0dca468 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -217,6 +217,11 @@ export default class MagicString {
   isEmpty(): boolean;
   length(): number;
 
+  /**
+   * Indicates if the string has been changed.
+   */
+  hasChanged(): boolean;
+
   original: string;
   /**
    * Returns the generated string.
diff --git a/src/MagicString.js b/src/MagicString.js
index 6632043..b67bf18 100644
--- a/src/MagicString.js
+++ b/src/MagicString.js
@@ -713,6 +713,10 @@ export default class MagicString {
 		return this;
 	}
 
+	hasChanged() {
+		return this.original !== this.toString();
+	}
+
 	replace(searchValue, replacement) {
 		function getReplacement(match) {
 			if (typeof replacement === 'string') {
diff --git a/test/MagicString.js b/test/MagicString.js
index a97f157..25472ff 100644
--- a/test/MagicString.js
+++ b/test/MagicString.js
@@ -1278,6 +1278,26 @@ describe('MagicString', () => {
 		});
 	});
 
+	describe('hasChanged', () => {
+		it('should works', () => {
+			const s = new MagicString(' abcde   fghijkl ');
+
+			assert.ok(!s.hasChanged());
+		
+			assert.ok(s.clone().prepend('  ').hasChanged());
+			assert.ok(s.clone().overwrite(1, 2, 'b').hasChanged());
+			assert.ok(s.clone().remove(1, 6).hasChanged());
+
+			s.trim();
+
+			assert.ok(s.hasChanged());
+
+			const clone = s.clone();
+
+			assert.ok(clone.hasChanged());
+		});
+	});
+  
 	describe('replace', () => {
 		it('works with string replace', () => {
 			const code = '1 2 1 2';