diff --git a/news/3 Code Health/1953.md b/news/3 Code Health/1953.md
new file mode 100644
index 000000000000..4749e1048d14
--- /dev/null
+++ b/news/3 Code Health/1953.md	
@@ -0,0 +1 @@
+Fix rename refactoring unit tests.
diff --git a/src/client/common/extensions.ts b/src/client/common/extensions.ts
index 96e329532df9..ea4ec4d1bf3a 100644
--- a/src/client/common/extensions.ts
+++ b/src/client/common/extensions.ts
@@ -15,7 +15,7 @@ declare interface String {
      * By default lines are trimmed and empty lines are removed.
      * @param {SplitLinesOptions=} splitOptions - Options used for splitting the string.
      */
-    splitLines(splitOptions?: { trim: boolean, removeEmptyEntries?: boolean }): string[];
+    splitLines(splitOptions?: { trim: boolean; removeEmptyEntries?: boolean }): string[];
     /**
      * Appropriately formats a string so it can be used as an argument for a command in a shell.
      * E.g. if an argument contains a space, then it will be enclosed within double quotes.
@@ -33,10 +33,10 @@ declare interface String {
  * By default lines are trimmed and empty lines are removed.
  * @param {SplitLinesOptions=} splitOptions - Options used for splitting the string.
  */
-String.prototype.splitLines = function (this: string, splitOptions: { trim: boolean, removeEmptyEntries: boolean } = { removeEmptyEntries: true, trim: true }): string[] {
+String.prototype.splitLines = function (this: string, splitOptions: { trim: boolean; removeEmptyEntries: boolean } = { removeEmptyEntries: true, trim: true }): string[] {
     let lines = this.split(/\r?\n/g);
     if (splitOptions && splitOptions.trim) {
-        lines = lines.filter(line => line.trim());
+        lines = lines.map(line => line.trim());
     }
     if (splitOptions && splitOptions.removeEmptyEntries) {
         lines = lines.filter(line => line.length > 0);
diff --git a/src/test/refactor/rename.test.ts b/src/test/refactor/rename.test.ts
index cbc4f641ddf7..03bffd245899 100644
--- a/src/test/refactor/rename.test.ts
+++ b/src/test/refactor/rename.test.ts
@@ -9,6 +9,7 @@ import * as path from 'path';
 import * as typeMoq from 'typemoq';
 import { Range, TextEditorCursorStyle, TextEditorLineNumbersStyle, TextEditorOptions, window, workspace } from 'vscode';
 import { EXTENSION_ROOT_DIR } from '../../client/common/constants';
+import '../../client/common/extensions';
 import { BufferDecoder } from '../../client/common/process/decoder';
 import { ProcessService } from '../../client/common/process/proc';
 import { PythonExecutionFactory } from '../../client/common/process/pythonExecutionFactory';
@@ -47,7 +48,8 @@ suite('Refactor Rename', () => {
 
     test('Rename function in source without a trailing empty line', async () => {
         const sourceFile = path.join(EXTENSION_ROOT_DIR, 'src', 'test', 'pythonFiles', 'refactoring', 'source folder', 'without empty line.py');
-        const expectedDiff = `--- a/${path.basename(sourceFile)}${EOL}+++ b/${path.basename(sourceFile)}${EOL}@@ -1,8 +1,8 @@${EOL} import os${EOL} ${EOL}-def one():${EOL}+def three():${EOL}     return True${EOL} ${EOL} def two():${EOL}-    if one():${EOL}-        print(\"A\" + one())${EOL}+    if three():${EOL}+        print(\"A\" + three())${EOL}`;
+        const expectedDiff = `--- a/${path.basename(sourceFile)}${EOL}+++ b/${path.basename(sourceFile)}${EOL}@@ -1,8 +1,8 @@${EOL} import os${EOL} ${EOL}-def one():${EOL}+def three():${EOL}     return True${EOL} ${EOL} def two():${EOL}-    if one():${EOL}-        print(\"A\" + one())${EOL}+    if three():${EOL}+        print(\"A\" + three())${EOL}`
+            .splitLines({ removeEmptyEntries: false, trim: false });
 
         const proxy = new RefactorProxy(EXTENSION_ROOT_DIR, pythonSettings.object, path.dirname(sourceFile), serviceContainer.object);
         const textDocument = await workspace.openTextDocument(sourceFile);
@@ -55,11 +57,12 @@ suite('Refactor Rename', () => {
 
         const response = await proxy.rename<RenameResponse>(textDocument, 'three', sourceFile, new Range(7, 20, 7, 23), options);
         expect(response.results).to.be.lengthOf(1);
-        expect(response.results[0].diff).to.be.equal(expectedDiff);
+        expect(response.results[0].diff.splitLines({ removeEmptyEntries: false, trim: false })).to.be.deep.equal(expectedDiff);
     });
     test('Rename function in source with a trailing empty line', async () => {
         const sourceFile = path.join(EXTENSION_ROOT_DIR, 'src', 'test', 'pythonFiles', 'refactoring', 'source folder', 'with empty line.py');
-        const expectedDiff = `--- a/${path.basename(sourceFile)}${EOL}+++ b/${path.basename(sourceFile)}${EOL}@@ -1,8 +1,8 @@${EOL} import os${EOL} ${EOL}-def one():${EOL}+def three():${EOL}     return True${EOL} ${EOL} def two():${EOL}-    if one():${EOL}-        print(\"A\" + one())${EOL}+    if three():${EOL}+        print(\"A\" + three())${EOL}`;
+        const expectedDiff = `--- a/${path.basename(sourceFile)}${EOL}+++ b/${path.basename(sourceFile)}${EOL}@@ -1,8 +1,8 @@${EOL} import os${EOL} ${EOL}-def one():${EOL}+def three():${EOL}     return True${EOL} ${EOL} def two():${EOL}-    if one():${EOL}-        print(\"A\" + one())${EOL}+    if three():${EOL}+        print(\"A\" + three())${EOL}`
+            .splitLines({ removeEmptyEntries: false, trim: false });
 
         const proxy = new RefactorProxy(EXTENSION_ROOT_DIR, pythonSettings.object, path.dirname(sourceFile), serviceContainer.object);
         const textDocument = await workspace.openTextDocument(sourceFile);
@@ -67,6 +70,6 @@ suite('Refactor Rename', () => {
 
         const response = await proxy.rename<RenameResponse>(textDocument, 'three', sourceFile, new Range(7, 20, 7, 23), options);
         expect(response.results).to.be.lengthOf(1);
-        expect(response.results[0].diff).to.be.equal(expectedDiff);
+        expect(response.results[0].diff.splitLines({ removeEmptyEntries: false, trim: false })).to.be.deep.equal(expectedDiff);
     });
 });