Formatter line continuation awareness hooks.

pkg/analyzer/test/services/formatter_test.dart

Index: pkg/analyzer/test/services/formatter_test.dart
===================================================================
--- pkg/analyzer/test/services/formatter_test.dart	(revision 31147)
+++ pkg/analyzer/test/services/formatter_test.dart	(working copy)
@@ -914,6 +914,101 @@
                           transforms: false);
     });
 
+    test('line continuations - 1', () {
+      expectStmtFormatsTo(
+          'if (x &&\n'
+          '    y) {\n'
+          '  print("yes!");\n'
+          '}',
+          'if (x &&\n'
+          '    y) {\n'
+          '  print("yes!");\n'
+          '}'
+      );
+      expectStmtFormatsTo(
+          'var x =\n'
+          '    1234567890;',
+          'var x =\n'
+          '    1234567890;'
+      );
+      expectStmtFormatsTo(
+          'foo() {\n'
+          '  var x = 0;\n'
+          '  x =\n'
+          '      1234567890;\n'
+          '}',
+          'foo() {\n'
+          '  var x = 0;\n'
+          '  x =\n'
+          '      1234567890;\n'
+          '}'
+      );
+      expectStmtFormatsTo(
+          'foo() {\n'
+          '  while (true &&\n'
+          '      true) {\n'
+          '    print("!");\n'
+          '  }\n'
+          '}',
+          'foo() {\n'
+          '  while (true &&\n'
+          '      true) {\n'
+          '    print("!");\n'
+          '  }\n'
+          '}'
+      );
+      expectStmtFormatsTo(
+          'foo() {\n'
+          '  do {\n'
+          '    print("!");\n'
+          '  } while (true &&\n'
+          '      true);\n'
+          '}',
+          'foo() {\n'
+          '  do {\n'
+          '    print("!");\n'
+          '  } while (true &&\n'
+          '      true);\n'
+          '}'
+      );
+      expectStmtFormatsTo(
+          'int foo() {\n'
+          '  return\n'
+          '      foo();\n'
+          '}',
+          'int foo() {\n'
+          '  return\n'
+          '      foo();\n'
+          '}'
+      );
+      expectStmtFormatsTo(
+          'true ? foo() :\n'
+          '    bar();',
+          'true ? foo() :\n'
+          '    bar();'
+      );
+      expectCUFormatsTo(
+          'import "dart:core" as\n'
+          '    core;\n',
+          'import "dart:core" as\n'
+          '    core;\n'
+      );
+      expectCUFormatsTo(
+          'export "package:foo/foo.dart" show\n'
+          '    Foo;\n',
+          'export "package:foo/foo.dart" show\n'
+          '    Foo;\n'
+      );
+      expectCUFormatsTo(
+          'class Foo extends Bar implements\n'
+          '    Baz {\n'
+          '}\n',
+          'class Foo extends Bar implements\n'
+          '    Baz {\n'
+          '}\n'
+      );
+    });
+
     test('initialIndent', () {
       var formatter = new CodeFormatter(
           new FormatterOptions(initialIndentationLevel: 2));