From 003c28f1ef8ef093d2927901af8fafd3b388dc88 Mon Sep 17 00:00:00 2001
From: Mine Starks <mineyalc@microsoft.com>
Date: Tue, 11 Jul 2017 13:32:56 -0700
Subject: [PATCH] Fix caret update logic in fourslash tests

---
 src/harness/fourslash.ts                   | 13 ++++++++-----
 tests/cases/fourslash/formattingOnEnter.ts |  6 +++++-
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index fc8299f57e9..9688c565f57 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -1790,17 +1790,20 @@ namespace FourSlash {
                 this.editScriptAndUpdateMarkers(fileName, offsetStart, offsetEnd, edit.newText);
                 const editDelta = edit.newText.length - edit.span.length;
                 if (offsetStart <= this.currentCaretPosition) {
-                    this.currentCaretPosition += editDelta;
+                    if (offsetEnd <= this.currentCaretPosition) {
+                        // The entirety of the edit span falls before the caret position, shift the caret accordingly
+                        this.currentCaretPosition += editDelta;
+                    }
+                    else {
+                        // The span being replaced includes the caret position, place the caret at the beginning of the span
+                        this.currentCaretPosition = offsetStart;
+                    }
                 }
                 runningOffset += editDelta;
                 // TODO: Consider doing this at least some of the time for higher fidelity. Currently causes a failure (bug 707150)
                 // this.languageService.getScriptLexicalStructure(fileName);
             }
 
-            if (this.currentCaretPosition < 0) {
-                this.currentCaretPosition = 0;
-            }
-
             if (isFormattingEdit) {
                 const newContent = this.getFileContent(fileName);
 
diff --git a/tests/cases/fourslash/formattingOnEnter.ts b/tests/cases/fourslash/formattingOnEnter.ts
index 1c0915e839e..0e7d5af1a6d 100644
--- a/tests/cases/fourslash/formattingOnEnter.ts
+++ b/tests/cases/fourslash/formattingOnEnter.ts
@@ -6,4 +6,8 @@
 
 goTo.marker();
 edit.insertLine("");
-verify.currentLineContentIs('class bar {');
+verify.currentFileContentIs(
+`class foo { }
+class bar {
+}
+// new line here`);