Add static `trimmedRange` to `TextRange`

src/annotator/anchoring/test/text-range-test.js

@@ -452,5 +452,21 @@ describe('annotator/anchoring/text-range', () => {
         assert.equal(textRange.end.offset, 10);
       });
     });
+
+    describe('trimmedRange', () => {
+      it('adjusts Range start and end positions to remove whitespace', () => {
+        const el = document.createElement('div');
+        el.textContent = ' one two three ';
+
+        const range = new Range();
+        range.selectNodeContents(el);
+
+        const textRange = TextRange.fromRange(range).toRange();
+        const trimmedRange = TextRange.trimmedRange(range);
+
+        assert.equal(trimmedRange.startOffset, textRange.startOffset + 1);
+        assert.equal(trimmedRange.endOffset, textRange.endOffset - 1);
+      });
+    });
   });
 });

src/annotator/anchoring/text-range.ts

+import { trimRange } from './trim-range';
+
 /**
  * Return the combined length of text nodes contained in `node`.
  */
@@ -314,4 +316,12 @@ export class TextRange {
       new TextPosition(root, end)
     );
   }
+
+  /**
+   * Return a new Range representing `range` trimmed of any leading or trailing
+   * whitespace
+   */
+  static trimmedRange(range: Range): Range {
+    return trimRange(TextRange.fromRange(range).toRange());
+  }
 }