fix: trim replaced content with space (#257)

Co-authored-by: poyoho <panyoho@gamil.com>

src/Chunk.js

@@ -99,6 +99,13 @@ export default class Chunk {
 		this.end = index;
 
 		if (this.edited) {
+			// after split we should save the edit content record into the correct chunk
+			// to make sure sourcemap correct
+			// For example:
+			// '  test'.trim()
+			//     split   -> '  ' + 'test'
+			//   ✔️ edit    -> '' + 'test'
+			//   ✖️ edit    -> 'test' + '' 
 			// TODO is this block necessary?...
 			newChunk.edit('', false);
 			this.content = '';
@@ -127,6 +134,10 @@ export default class Chunk {
 		if (trimmed.length) {
 			if (trimmed !== this.content) {
 				this.split(this.start + trimmed.length).edit('', undefined, true);
+				if (this.edited) {
+					// save the change, if it has been edited
+					this.edit(trimmed, this.storeName, true);
+				}
 			}
 			return true;
 		} else {
@@ -145,7 +156,11 @@ export default class Chunk {
 
 		if (trimmed.length) {
 			if (trimmed !== this.content) {
-				this.split(this.end - trimmed.length);
+				const newChunk = this.split(this.end - trimmed.length);
+				if (this.edited) {
+					// save the change, if it has been edited
+					newChunk.edit(trimmed, this.storeName, true);
+				}
 				this.edit('', undefined, true);
 			}
 			return true;

test/MagicString.js

@@ -1338,6 +1338,27 @@ describe('MagicString', () => {
 			assert.equal(s.toString(), 'defghi');
 		});
 
+		it('should trim replaced content with end space', () => {
+			const s = new MagicString('  test  ');
+			s.overwrite(2, 6, 'abcd  ');
+			s.trimEnd();
+			assert.equal(s.toString(), '  abcd');
+		});
+
+		it('should trim replaced content with start space', () => {
+			const s = new MagicString('  test  ');
+			s.overwrite(0, 6, '  abcd');
+			s.trimStart();
+			assert.equal(s.toString(), 'abcd  ');
+		});
+
+		it('should trim replaced content with start space', () => {
+			const s = new MagicString('  test  ');
+			s.overwrite(0, 8, '  abcd  ');
+			s.trim();
+			assert.equal(s.toString(), 'abcd');
+		});
+
 		it('should trim original content before replaced content', () => {
 			const s = new MagicString('abc   def');