Connect analyzer's AnalysisError object to front_end's CompilationError.

pkg/analyzer/test/generated/error_test.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/string_source.dart';
+import 'package:front_end/src/scanner/errors.dart';
+import 'package:source_span/src/span.dart';
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(AnalysisErrorTest);
+  });
+}
+
+@reflectiveTest
+class AnalysisErrorTest {
+  void test_location() {
+    String text = '''
+line one
+line two
+line three
+line four
+''';
+    String path = '/source.dart';
+    Source source = new StringSource(text, path);
+    int offset = text.indexOf('thr');
+    int length = 3;
+    ErrorCode errorCode = ScannerErrorCode.UNTERMINATED_STRING_LITERAL;
+    AnalysisError error = new AnalysisError(source, offset, length, errorCode);
+    SourceSpan span = error.span;
+    expect(span.start.line, 2);
+    expect(span.start.column, 5);
+    expect(span.start.offset, offset);
+    expect(span.end.line, 2);
+    expect(span.end.column, 8);
+    expect(span.end.offset, offset + length);
+    expect(span.text, 'thr');
+    expect(span.sourceUrl, new Uri.file(path));
+  }
+}