Merge pull request #1456 from Microsoft/mergeMarkers

Make the compiler resilient to encountering merge conflict markers in a source code file.

tests/baselines/reference/conflictMarkerTrivia1.errors.txt

@@ -0,0 +1,25 @@
+tests/cases/compiler/conflictMarkerTrivia1.ts(2,1): error TS1184: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerTrivia1.ts(4,1): error TS1184: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerTrivia1.ts(6,1): error TS1184: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerTrivia1.ts(3,5): error TS2300: Duplicate identifier 'v'.
+tests/cases/compiler/conflictMarkerTrivia1.ts(5,5): error TS2300: Duplicate identifier 'v'.
+
+
+==== tests/cases/compiler/conflictMarkerTrivia1.ts (5 errors) ====
+    class C {
+    <<<<<<< HEAD
+    
+!!! error TS1184: Merge conflict marker encountered.
+        v = 1;
+        ~
+!!! error TS2300: Duplicate identifier 'v'.
+    =======
+    
+!!! error TS1184: Merge conflict marker encountered.
+        v = 2;
+        ~
+!!! error TS2300: Duplicate identifier 'v'.
+    >>>>>>> Branch-a
+    
+!!! error TS1184: Merge conflict marker encountered.
+    }

tests/cases/compiler/conflictMarkerTrivia1.ts

@@ -0,0 +1,7 @@
+class C {
+<<<<<<< HEAD
+    v = 1;
+=======
+    v = 2;
+>>>>>>> Branch-a
+}

tests/cases/fourslash/formatConflictMarker1.ts

@@ -0,0 +1,18 @@
+/// <reference path='fourslash.ts' />
+
+////class C {
+////<<<<<<< HEAD
+////    v = 1;
+////=======
+////v = 2;
+////>>>>>>> Branch - a
+////}
+
+format.document();
+verify.currentFileContentIs("class C {\r\n\
+<<<<<<< HEAD\r\n\
+    v = 1;\r\n\
+=======\r\n\
+    v = 2;\r\n\
+>>>>>>> Branch - a\r\n\
+}");

tests/cases/unittests/services/colorization.ts

@@ -317,7 +317,9 @@ describe('Colorization', function () {
                 operator("<"),
                 identifier("number"),
                 finalEndOfLineState(ts.EndOfLineState.Start));
+        });
 
+        it("ClassifiesConflictTokens", () => {
             // no longer in something that looks generic.
             test("Foo<Foo> number",
                 ts.EndOfLineState.Start,
@@ -327,6 +329,33 @@ describe('Colorization', function () {
                 operator(">"),
                 keyword("number"),
                 finalEndOfLineState(ts.EndOfLineState.Start));
+
+            // Test conflict markers.
+            test(
+"class C {\r\n\
+<<<<<<< HEAD\r\n\
+    v = 1;\r\n\
+=======\r\n\
+    v = 2;\r\n\
+>>>>>>> Branch - a\r\n\
+}",
+                ts.EndOfLineState.Start,
+                keyword("class"),
+                identifier("C"),
+                punctuation("{"),
+                comment("<<<<<<< HEAD"),
+                identifier("v"),
+                operator("="),
+                numberLiteral("1"),
+                punctuation(";"),
+                comment("======="),
+                identifier("v"),
+                operator("="),
+                numberLiteral("2"),
+                punctuation(";"),
+                comment(">>>>>>> Branch - a"),
+                punctuation("}"),
+                finalEndOfLineState(ts.EndOfLineState.Start));
         });
     });
 });