fix(compiler-cli): handle \r\n line-endings correctly in source-mapping (#40187)

Previously `\r\n` was being treated as a single character in source-map
line start positions, which caused segment positions to become offset.

Now the `\r` is ignored when splitting, leaving it at the end of the
previous line, which solves the offsetting problem, and does not affect
source-mappings.

Fixes #40169
Fixes #39654

PR Close #40187

Author: petebacondarwin

packages/compiler-cli/src/ngtsc/sourcemaps/src/source_file.ts

@@ -446,5 +446,5 @@ export function computeStartOfLinePositions(str: string) {
 }
 
 function computeLineLengths(str: string): number[] {
-  return (str.split(/\r?\n/)).map(s => s.length);
+  return (str.split(/\n/)).map(s => s.length);
 }

packages/compiler-cli/src/ngtsc/sourcemaps/test/segment_marker_spec.ts

@@ -79,31 +79,32 @@ describe('SegmentMarker utils', () => {
     it('should return a new marker offset by the given chars', () => {
       const startOfLinePositions =
           computeStartOfLinePositions('012345\n0123456789\r\n012*4567\n0123456');
-      const marker = {line: 2, column: 3, position: 21, next: undefined};
+      const marker = {line: 2, column: 3, position: 22, next: undefined};
+
       expect(offsetSegment(startOfLinePositions, marker, 1))
-          .toEqual({line: 2, column: 4, position: 22, next: undefined});
+          .toEqual({line: 2, column: 4, position: 23, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, 2))
-          .toEqual({line: 2, column: 5, position: 23, next: undefined});
+          .toEqual({line: 2, column: 5, position: 24, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, 4))
-          .toEqual({line: 2, column: 7, position: 25, next: undefined});
+          .toEqual({line: 2, column: 7, position: 26, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, 6))
-          .toEqual({line: 3, column: 0, position: 27, next: undefined});
+          .toEqual({line: 3, column: 0, position: 28, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, 8))
-          .toEqual({line: 3, column: 2, position: 29, next: undefined});
+          .toEqual({line: 3, column: 2, position: 30, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, 20))
-          .toEqual({line: 3, column: 14, position: 41, next: undefined});
+          .toEqual({line: 3, column: 14, position: 42, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, -1))
-          .toEqual({line: 2, column: 2, position: 20, next: undefined});
+          .toEqual({line: 2, column: 2, position: 21, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, -2))
-          .toEqual({line: 2, column: 1, position: 19, next: undefined});
+          .toEqual({line: 2, column: 1, position: 20, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, -3))
-          .toEqual({line: 2, column: 0, position: 18, next: undefined});
+          .toEqual({line: 2, column: 0, position: 19, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, -4))
-          .toEqual({line: 1, column: 10, position: 17, next: undefined});
+          .toEqual({line: 1, column: 11, position: 18, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, -6))
-          .toEqual({line: 1, column: 8, position: 15, next: undefined});
+          .toEqual({line: 1, column: 9, position: 16, next: undefined});
       expect(offsetSegment(startOfLinePositions, marker, -16))
-          .toEqual({line: 0, column: 5, position: 5, next: undefined});
+          .toEqual({line: 0, column: 6, position: 6, next: undefined});
     });
   });
 });

packages/compiler-cli/src/ngtsc/sourcemaps/test/source_file_spec.ts

@@ -677,8 +677,9 @@ runInEachFileSystem(() => {
         expect(computeStartOfLinePositions('abc\n')).toEqual([0, 4]);
         expect(computeStartOfLinePositions('\nabc')).toEqual([0, 1]);
         expect(computeStartOfLinePositions('abc\ndefg')).toEqual([0, 4]);
-        expect(computeStartOfLinePositions('abc\r\n')).toEqual([0, 4]);
-        expect(computeStartOfLinePositions('abc\r\ndefg')).toEqual([0, 4]);
+        expect(computeStartOfLinePositions('abc\r\n')).toEqual([0, 5]);
+        expect(computeStartOfLinePositions('abc\r\ndefg')).toEqual([0, 5]);
+        expect(computeStartOfLinePositions('abc\uD83D\uDE80\ndef🚀\r\n')).toEqual([0, 6, 13]);
       });
     });
   });