1 files changed, 8 insertions, 66 deletions
diff --git a/spec/ruby/core/string/start_with_spec.rb b/spec/ruby/core/string/start_with_spec.rb
index 4e12c1a445..8b0ba6b5a7 100644
--- a/spec/ruby/core/string/start_with_spec.rb
+++ b/spec/ruby/core/string/start_with_spec.rb
@@ -1,76 +1,18 @@
 # -*- encoding: utf-8 -*-
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
+require_relative '../../shared/string/start_with'
 
 describe "String#start_with?" do
-  it "returns true only if beginning match" do
-    s = "hello"
-    s.start_with?('h').should be_true
-    s.start_with?('hel').should be_true
-    s.start_with?('el').should be_false
-  end
-
-  it "returns true only if any beginning match" do
-    "hello".start_with?('x', 'y', 'he', 'z').should be_true
-  end
-
-  it "returns true if the search string is empty" do
-    "hello".start_with?("").should be_true
-    "".start_with?("").should be_true
-  end
-
-  it "converts its argument using :to_str" do
-    s = "hello"
-    find = mock('h')
-    find.should_receive(:to_str).and_return("h")
-    s.start_with?(find).should be_true
-  end
+  it_behaves_like :start_with, :to_s
 
-  it "ignores arguments not convertible to string" do
-    "hello".start_with?().should be_false
-    lambda { "hello".start_with?(1) }.should raise_error(TypeError)
-    lambda { "hello".start_with?(["h"]) }.should raise_error(TypeError)
-    lambda { "hello".start_with?(1, nil, "h") }.should raise_error(TypeError)
+  # Here and not in the shared examples because this is invalid as a Symbol
+  it "matches part of a character with the same part" do
+    "\xA9".should.start_with?("\xA9") # A9 is not a character head for UTF-8
   end
 
-  it "uses only the needed arguments" do
-    find = mock('h')
-    find.should_not_receive(:to_str)
-    "hello".start_with?("h",find).should be_true
-  end
-
-  it "works for multibyte strings" do
-    "céréale".start_with?("cér").should be_true
-  end
-
-  ruby_version_is "2.5" do
-    it "supports regexps" do
-      regexp = /[h1]/
-      "hello".start_with?(regexp).should be_true
-      "1337".start_with?(regexp).should be_true
-      "foxes are 1337".start_with?(regexp).should be_false
-      "chunky\n12bacon".start_with?(/12/).should be_false
-    end
-
-    it "supports regexps with ^ and $ modifiers" do
-      regexp1 = /^\d{2}/
-      regexp2 = /\d{2}$/
-      "12test".start_with?(regexp1).should be_true
-      "test12".start_with?(regexp1).should be_false
-      "12test".start_with?(regexp2).should be_false
-      "test12".start_with?(regexp2).should be_false
-    end
-
-    it "sets Regexp.last_match if it returns true" do
-      regexp = /test-(\d+)/
-      "test-1337".start_with?(regexp).should be_true
-      Regexp.last_match.should_not be_nil
-      Regexp.last_match[1].should == "1337"
-      $1.should == "1337"
-
-      "test-asdf".start_with?(regexp).should be_false
-      Regexp.last_match.should be_nil
-      $1.should be_nil
-    end
+  it "checks we are matching only part of a character" do
+    "\xe3\x81\x82".size.should == 1
+    "\xe3\x81\x82".should_not.start_with?("\xe3")
   end
 end