From d5546bf8743388caaf82770e837b5ffec5003910 Mon Sep 17 00:00:00 2001
From: Filip Hracek <filip.hracek@gmail.com>
Date: Tue, 28 Feb 2017 17:58:55 -0800
Subject: [PATCH] Allow quotes and newlines in string literal
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Allows creating string literals like “hello ‘world’” and “””hello\nworld”””.
---
 lib/src/builders/expression.dart   | 12 +++++++++++-
 test/builders/expression_test.dart | 26 ++++++++++++++++++++++++--
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/lib/src/builders/expression.dart b/lib/src/builders/expression.dart
index 4565cb4..24d0f62 100644
--- a/lib/src/builders/expression.dart
+++ b/lib/src/builders/expression.dart
@@ -84,7 +84,7 @@ Literal _literal(value) {
   } else if (value is bool) {
     return value ? _true : _false;
   } else if (value is String) {
-    return astFactory.simpleStringLiteral(stringToken("'$value'"), value);
+    return astFactory.simpleStringLiteral(stringToken(_quote(value)), value);
   } else if (value is int) {
     return astFactory.integerLiteral(stringToken('$value'), value);
   } else if (value is double) {
@@ -93,6 +93,16 @@ Literal _literal(value) {
   throw new ArgumentError.value(value, 'Unsupported');
 }
 
+/// Quotes the string literal. It is assumed that the [value] is meant to be
+/// the raw string, so all `\` are escaped.
+String _quote(String value) {
+  value = value.replaceAll(r'\', r'\\').replaceAll(r"'", r"\'");
+  if (value.contains('\n')) {
+    return "'''$value'''";
+  }
+  return "'$value'";
+}
+
 /// Implements much of [ExpressionBuilder].
 abstract class AbstractExpressionMixin implements ExpressionBuilder {
   @override
diff --git a/test/builders/expression_test.dart b/test/builders/expression_test.dart
index 21a4876..6467d4b 100644
--- a/test/builders/expression_test.dart
+++ b/test/builders/expression_test.dart
@@ -29,8 +29,30 @@ void main() {
       expect(literal(5.5), equalsSource(r'5.5'));
     });
 
-    test('should emit a string', () {
-      expect(literal('Hello'), equalsSource(r"'Hello'"));
+    group('should emit a string', () {
+      test('simple', () {
+        expect(literal('Hello'), equalsSource(r"'Hello'"));
+      });
+
+      test("with a '", () {
+        expect(literal("Hello'"), equalsSource(r"'Hello\''"));
+      });
+
+      test(r"with a \'", () {
+        expect(literal(r"Hello\'"), equalsSource(r"'Hello\\\''"));
+      });
+
+      test(r"with a \\'", () {
+        expect(literal(r"Hello\\'"), equalsSource(r"'Hello\\\\\''"));
+      });
+
+      test(r"with a newline", () {
+        expect(literal("Hello\nworld"), equalsSource("'''Hello\nworld'''"));
+      });
+
+      test(r"with a newline and ending with a '", () {
+        expect(literal("Hello\nworld'"), equalsSource("'''Hello\nworld\\''''"));
+      });
     });
 
     test('should emit a list', () {