1 files changed, 98 insertions, 0 deletions
diff --git a/spec/ruby/library/stringscanner/scan_byte_spec.rb b/spec/ruby/library/stringscanner/scan_byte_spec.rb
new file mode 100644
index 0000000000..8fd77270e4
--- /dev/null
+++ b/spec/ruby/library/stringscanner/scan_byte_spec.rb
@@ -0,0 +1,98 @@
+require_relative '../../spec_helper'
+require 'strscan'
+
+version_is StringScanner::Version, "3.1.1" do # ruby_version_is "3.4"
+  describe "StringScanner#scan_byte" do
+    it "scans one byte and returns it as on Integer" do
+      s = StringScanner.new('abc') # "abc".bytes => [97, 98, 99]
+      s.scan_byte.should == 97
+      s.scan_byte.should == 98
+      s.scan_byte.should == 99
+    end
+
+    it "is not multi-byte character sensitive" do
+      s = StringScanner.new("あ") # "あ".bytes => [227, 129, 130]
+      s.scan_byte.should == 227
+      s.scan_byte.should == 129
+      s.scan_byte.should == 130
+    end
+
+    it "returns nil at the end of the string" do
+      s = StringScanner.new('a')
+      s.scan_byte # skip one
+      s.scan_byte.should == nil
+      s.pos.should == 1
+    end
+
+    it "changes current position" do
+      s = StringScanner.new('abc')
+      s.pos.should == 0
+      s.scan_byte
+      s.pos.should == 1
+    end
+
+    it "sets the last match result" do
+      s = StringScanner.new('abc')
+      s.pos = 1
+      s.scan_byte
+
+      s.pre_match.should == "a"
+      s.matched.should == "b"
+      s.post_match.should == "c"
+    end
+
+    describe "#[] successive call with a capture group name" do
+      # https://github.com/ruby/strscan/issues/139
+      version_is StringScanner::Version, "3.1.1"..."3.1.3" do # ruby_version_is "3.4.0"..."3.4.3"
+        it "returns nil" do
+          s = StringScanner.new("abc")
+          s.scan_byte
+          s.should.matched?
+          s[:a].should == nil
+        end
+      end
+      version_is StringScanner::Version, "3.1.3" do # ruby_version_is "3.4.3"
+        it "raises IndexError" do
+          s = StringScanner.new("abc")
+          s.scan_byte
+          s.should.matched?
+          -> { s[:a] }.should.raise(IndexError)
+        end
+      end
+
+      it "returns a matching character when given Integer index" do
+        s = StringScanner.new("This is a test")
+        s.scan_byte
+        s[0].should == "T"
+      end
+
+      # https://github.com/ruby/strscan/issues/135
+      version_is StringScanner::Version, "3.1.1"..."3.1.3" do # ruby_version_is "3.4.0"..."3.4.3"
+        it "ignores the previous matching with Regexp" do
+          s = StringScanner.new("abc")
+
+          s.exist?(/(?<a>a)/)
+          s.should.matched?
+          s[:a].should == "a"
+
+          s.scan_byte
+          s.should.matched?
+          s[:a].should == nil
+        end
+      end
+      version_is StringScanner::Version, "3.1.3" do # ruby_version_is "3.4.0"..."3.4.3"
+        it "ignores the previous matching with Regexp" do
+          s = StringScanner.new("abc")
+
+          s.exist?(/(?<a>a)/)
+          s.should.matched?
+          s[:a].should == "a"
+
+          s.scan_byte
+          s.should.matched?
+          -> { s[:a] }.should.raise(IndexError)
+        end
+      end
+    end
+  end
+end