Add range API to serialize addon

Fixes #4876
Fixes #4871

addons/addon-serialize/src/SerializeAddon.test.ts

@@ -9,7 +9,6 @@ import { SerializeAddon } from './SerializeAddon';
 import { Terminal } from 'browser/public/Terminal';
 import { SelectionModel } from 'browser/selection/SelectionModel';
 import { IBufferService } from 'common/services/Services';
-import { OptionsService } from 'common/services/OptionsService';
 import { ThemeService } from 'browser/services/ThemeService';
 
 function sgr(...seq: string[]): string {
@@ -83,6 +82,36 @@ describe('SerializeAddon', () => {
       await writeP(terminal, sgr('32') + '> ' + sgr('0'));
       assert.equal(serializeAddon.serialize(), '\u001b[32m> \u001b[0m');
     });
+
+    describe('ISerializeOptions.range', () => {
+      it('should serialize the top line', async () => {
+        await writeP(terminal, 'hello\r\nworld');
+        assert.equal(serializeAddon.serialize({
+          range: {
+            start: 0,
+            end: 0
+          }
+        }), 'hello');
+      });
+      it('should serialize multiple lines from the top', async () => {
+        await writeP(terminal, 'hello\r\nworld');
+        assert.equal(serializeAddon.serialize({
+          range: {
+            start: 0,
+            end: 1
+          }
+        }), 'hello\r\nworld');
+      });
+      it('should serialize lines in the middle', async () => {
+        await writeP(terminal, 'hello\r\nworld');
+        assert.equal(serializeAddon.serialize({
+          range: {
+            start: 1,
+            end: 1
+          }
+        }), 'world');
+      });
+    });
   });
 
   describe('html', () => {