Add String.replaceFirstMapped.

tests/corelib/string_replace_test.dart

 // Copyright (c) 2011, 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:expect/expect.dart";
 
-class StringReplaceTest {
-  static testMain() {
-    Expect.equals(
-        "AtoBtoCDtoE", "AfromBtoCDtoE".replaceFirst("from", "to"));
-
-    // Test with the replaced string at the begining.
-    Expect.equals(
-        "toABtoCDtoE", "fromABtoCDtoE".replaceFirst("from", "to"));
-
-    // Test with the replaced string at the end.
-    Expect.equals(
-        "toABtoCDtoEto", "fromABtoCDtoEto".replaceFirst("from", "to"));
-
-    // Test when there are no occurence of the string to replace.
-    Expect.equals("ABC", "ABC".replaceFirst("from", "to"));
-
-    // Test when the string to change is the empty string.
-    Expect.equals("", "".replaceFirst("from", "to"));
-
-    // Test when the string to change is a substring of the string to
-    // replace.
-    Expect.equals("fro", "fro".replaceFirst("from", "to"));
-
-    // Test when the string to change is the replaced string.
-    Expect.equals("to", "from".replaceFirst("from", "to"));
-
-    // Test when the string to change is the replacement string.
-    Expect.equals("to", "to".replaceFirst("from", "to"));
-
-    // Test replacing by the empty string.
-    Expect.equals("", "from".replaceFirst("from", ""));
-    Expect.equals("AB", "AfromB".replaceFirst("from", ""));
-
-    // Test changing the empty string.
-    Expect.equals("to", "".replaceFirst("", "to"));
-
-    // Test replacing the empty string.
-    Expect.equals("toAtoBtoCto", "AtoBtoCto".replaceFirst("", "to"));
-
-    // Test startIndex.
-    Expect.equals(
-        "foo-AAA-foo-bar", "foo-bar-foo-bar".replaceFirst("bar", "AAA", 4));
-
-    // Test startIndex skipping one case at the begining.
-    Expect.equals(
-        "foo-bar-AAA-bar", "foo-bar-foo-bar".replaceFirst("foo", "AAA", 1));
-
-    // Test startIndex skipping one case at the begining.
-    Expect.equals(
-        "foo-bar-foo-AAA", "foo-bar-foo-bar".replaceFirst("bar", "AAA", 5));
-
-    // Test startIndex replacing with the empty string.
-    Expect.equals(
-        "foo-bar--bar", "foo-bar-foo-bar".replaceFirst("foo", "", 1));
-
-    // Test startIndex with a RegExp with carat
-    Expect.equals(
-        "foo-bar-foo-bar",
-        "foo-bar-foo-bar".replaceFirst(new RegExp(r"^foo"), "", 8));
-
-    // Test startIndex with a RegExp
-    Expect.equals(
-        "aaa{3}X{3}", "aaa{3}aaa{3}".replaceFirst(new RegExp(r"a{3}"), "X", 1));
-
-    // Test startIndex with regexp-looking String
-    Expect.equals(
-        "aaa{3}aaX", "aaa{3}aaa{3}".replaceFirst("a{3}", "X", 3));
-
-    // Test negative startIndex
-    Expect.throws(
-        () => "hello".replaceFirst("h", "X", -1), (e) => e is RangeError);
-
-    // Test startIndex too large
-    Expect.throws(
-        () => "hello".replaceFirst("h", "X", 6), (e) => e is RangeError);
-
-    // Test null startIndex
-    Expect.throws(
-        () => "hello".replaceFirst("h", "X", null), (e) => e is ArgumentError);
-
-    // Test object startIndex
-    Expect.throws(
-        () => "hello".replaceFirst("h", "X", new Object()));
-  }
+main() {
+  // Test replaceFirst.
+  Expect.equals(
+      "AtoBtoCDtoE", "AfromBtoCDtoE".replaceFirst("from", "to"));
+
+  // Test with the replaced string at the begining.
+  Expect.equals(
+      "toABtoCDtoE", "fromABtoCDtoE".replaceFirst("from", "to"));
+
+  // Test with the replaced string at the end.
+  Expect.equals(
+      "toABtoCDtoEto", "fromABtoCDtoEto".replaceFirst("from", "to"));
+
+  // Test when there are no occurence of the string to replace.
+  Expect.equals("ABC", "ABC".replaceFirst("from", "to"));
+
+  // Test when the string to change is the empty string.
+  Expect.equals("", "".replaceFirst("from", "to"));
+
+  // Test when the string to change is a substring of the string to
+  // replace.
+  Expect.equals("fro", "fro".replaceFirst("from", "to"));
+
+  // Test when the string to change is the replaced string.
+  Expect.equals("to", "from".replaceFirst("from", "to"));
+
+  // Test when the string to change is the replacement string.
+  Expect.equals("to", "to".replaceFirst("from", "to"));
+
+  // Test replacing by the empty string.
+  Expect.equals("", "from".replaceFirst("from", ""));
+  Expect.equals("AB", "AfromB".replaceFirst("from", ""));
+
+  // Test changing the empty string.
+  Expect.equals("to", "".replaceFirst("", "to"));
+
+  // Test replacing the empty string.
+  Expect.equals("toAtoBtoCto", "AtoBtoCto".replaceFirst("", "to"));
+
+  // Test startIndex.
+  Expect.equals(
+      "foo-AAA-foo-bar", "foo-bar-foo-bar".replaceFirst("bar", "AAA", 4));
+
+  // Test startIndex skipping one case at the begining.
+  Expect.equals(
+      "foo-bar-AAA-bar", "foo-bar-foo-bar".replaceFirst("foo", "AAA", 1));
+
+  // Test startIndex skipping one case at the begining.
+  Expect.equals(
+      "foo-bar-foo-AAA", "foo-bar-foo-bar".replaceFirst("bar", "AAA", 5));
+
+  // Test startIndex replacing with the empty string.
+  Expect.equals(
+      "foo-bar--bar", "foo-bar-foo-bar".replaceFirst("foo", "", 1));
+
+  // Test startIndex with a RegExp with carat
+  Expect.equals(
+      "foo-bar-foo-bar",
+      "foo-bar-foo-bar".replaceFirst(new RegExp(r"^foo"), "", 8));
+
+  // Test startIndex with a RegExp
+  Expect.equals(
+      "aaa{3}X{3}", "aaa{3}aaa{3}".replaceFirst(new RegExp(r"a{3}"), "X", 1));
+
+  // Test startIndex with regexp-looking String
+  Expect.equals(
+      "aaa{3}aaX", "aaa{3}aaa{3}".replaceFirst("a{3}", "X", 3));
+
+  // Test negative startIndex
+  Expect.throws(
+      () => "hello".replaceFirst("h", "X", -1), (e) => e is RangeError);
+
+  // Test startIndex too large
+  Expect.throws(
+      () => "hello".replaceFirst("h", "X", 6), (e) => e is RangeError);
+
+  // Test null startIndex
+  Expect.throws(
+      () => "hello".replaceFirst("h", "X", null), (e) => e is ArgumentError);
+
+  // Test object startIndex
+  Expect.throws(
+      () => "hello".replaceFirst("h", "X", new Object()));
+
+
+  // Test replaceFirstMapped.
+
+  Expect.equals(
+      "AtoBtoCDtoE", "AfromBtoCDtoE".replaceFirstMapped("from", (_) => "to"));
+
+  // Test with the replaced string at the begining.
+  Expect.equals(
+      "toABtoCDtoE", "fromABtoCDtoE".replaceFirstMapped("from", (_) => "to"));
+
+  // Test with the replaced string at the end.
+  Expect.equals(
+      "toABtoCDtoEto",
+      "fromABtoCDtoEto".replaceFirstMapped("from", (_) => "to"));
+
+  // Test when there are no occurence of the string to replace.
+  Expect.equals("ABC", "ABC".replaceFirstMapped("from", (_) => "to"));
+
+  // Test when the string to change is the empty string.
+  Expect.equals("", "".replaceFirstMapped("from", (_) => "to"));
+
+  // Test when the string to change is a substring of the string to
+  // replace.
+  Expect.equals("fro", "fro".replaceFirstMapped("from", (_) => "to"));
+
+  // Test when the string to change is the replaced string.
+  Expect.equals("to", "from".replaceFirstMapped("from", (_) => "to"));
+
+  // Test when the string to change is the replacement string.
+  Expect.equals("to", "to".replaceFirstMapped("from", (_) => "to"));
+
+  // Test replacing by the empty string.
+  Expect.equals("", "from".replaceFirstMapped("from", (_) => ""));
+  Expect.equals("AB", "AfromB".replaceFirstMapped("from", (_) => ""));
+
+  // Test changing the empty string.
+  Expect.equals("to", "".replaceFirstMapped("", (_) => "to"));
+
+  // Test replacing the empty string.
+  Expect.equals("toAtoBtoCto", "AtoBtoCto".replaceFirstMapped("", (_) => "to"));
+
+  // Test startIndex.
+  Expect.equals(
+      "foo-AAA-foo-bar",
+      "foo-bar-foo-bar".replaceFirstMapped("bar", (_) => "AAA", 4));
+
+  // Test startIndex skipping one case at the begining.
+  Expect.equals(
+      "foo-bar-AAA-bar",
+      "foo-bar-foo-bar".replaceFirstMapped("foo", (_) => "AAA", 1));
+
+  // Test startIndex skipping one case at the begining.
+  Expect.equals(
+      "foo-bar-foo-AAA",
+      "foo-bar-foo-bar".replaceFirstMapped("bar", (_) => "AAA", 5));
+
+  // Test startIndex replacing with the empty string.
+  Expect.equals(
+      "foo-bar--bar", "foo-bar-foo-bar".replaceFirstMapped("foo", (_) => "", 1));
+
+  // Test startIndex with a RegExp with carat
+  Expect.equals(
+      "foo-bar-foo-bar",
+      "foo-bar-foo-bar".replaceFirstMapped(new RegExp(r"^foo"), (_) => "", 8));
+
+  // Test startIndex with a RegExp
+  Expect.equals(
+      "aaa{3}X{3}",
+      "aaa{3}aaa{3}".replaceFirstMapped(new RegExp(r"a{3}"), (_) => "X", 1));
+
+  // Test startIndex with regexp-looking String
+  Expect.equals(
+      "aaa{3}aaX", "aaa{3}aaa{3}".replaceFirstMapped("a{3}", (_) => "X", 3));
+
+  // Test negative startIndex
+  Expect.throws(
+      () => "hello".replaceFirstMapped("h", (_) => "X", -1),
+      (e) => e is RangeError);
+
+  // Test startIndex too large
+  Expect.throws(
+      () => "hello".replaceFirstMapped("h", (_) => "X", 6),
+      (e) => e is RangeError);
+
+  // Test null startIndex
+  Expect.throws(
+      () => "hello".replaceFirstMapped("h", (_) => "X", null),
+      (e) => e is ArgumentError);
+
+  // Test object startIndex
+  Expect.throws(
+      () => "hello".replaceFirstMapped("h", (_) => "X", new Object()));
+
+  // Test replacement depending on argument.
+  Expect.equals(
+      "foo-BAR-foo-bar",
+      "foo-bar-foo-bar".replaceFirstMapped("bar", (v) => v[0].toUpperCase()));
+
+  Expect.equals(
+      "foo-[bar]-foo-bar",
+      "foo-bar-foo-bar".replaceFirstMapped("bar", (v) => "[${v[0]}]"));
+
+  Expect.equals("foo-foo-bar-foo-bar-foo-bar",
+                "foo-bar-foo-bar".replaceFirstMapped("bar", (v) => v.input));
+
+  // Test replacement throwing.
+  Expect.throws(
+    () => "foo-bar".replaceFirstMapped("bar", (v) => throw 42),
+    (e) => e == 42);
+
+  // Test replacement returning non-String.
+  var o = new Object();
+  Expect.equals("foo-$o", "foo-bar".replaceFirstMapped("bar",
+                                                       (v) { return o; }));
+
+  Expect.equals("foo-42", "foo-bar".replaceFirstMapped("bar",
+                                                       (v) { return 42; }));
+
+  // Test replacement returning object throwing on string-conversion.
+  var n = new Naughty();
+  Expect.throws(
+    () => "foo-bar".replaceFirstMapped("bar", (v) { return n; }));
 }
 
-main() {
-  StringReplaceTest.testMain();
+// Fails to return a String on toString, throws if converted by "$naughty".
+class Naughty {
+  toString() => this;
 }