[GR-18163] Fix StringIO#{gets, readline} when it is called with both separator and limit

PullRequest: truffleruby/4542

Author: andrykonchin

CHANGELOG.md

@@ -27,6 +27,7 @@ Compatibility:
 * Fix `Struct#initialize` when mixed positional and keyword arguments (#3855, @andrykonchin).
 * Fix `Integer.sqrt` for large values (#3872, @tompng).
 * Fix `Data#inspect` when data contains a recursive attribute (#3847, @andrykonchin).
+* Fix `StringIO#{gets,readline}` when it is called with both separator and limit to truncate the separator if the limit is exceeded (#3856, @andrykonchin).
 
 Performance:
 

lib/truffle/stringio.rb

@@ -779,7 +779,7 @@ def yaml_initialize(type, val)
         end
       else
         if stop = Primitive.find_string(string, sep, pos)
-          if limit && stop - pos >= limit
+          if limit && stop - pos + sep.bytesize >= limit
             stop = pos + limit
           else
             stop += sep.bytesize

spec/ruby/library/stringio/each_line_spec.rb

@@ -21,3 +21,7 @@
 describe "StringIO#each_line when passed limit" do
   it_behaves_like :stringio_each_limit, :each_line
 end
+
+describe "StringIO#each when passed separator and limit" do
+  it_behaves_like :stringio_each_separator_and_limit, :each_line
+end

spec/ruby/library/stringio/each_spec.rb

@@ -25,3 +25,7 @@
 describe "StringIO#each when passed limit" do
   it_behaves_like :stringio_each_limit, :each
 end
+
+describe "StringIO#each when passed separator and limit" do
+  it_behaves_like :stringio_each_separator_and_limit, :each
+end

spec/ruby/library/stringio/gets_spec.rb

@@ -1,250 +1,61 @@
 require_relative '../../spec_helper'
 require "stringio"
+require_relative "shared/gets"
 
-describe "StringIO#gets when passed [separator]" do
-  before :each do
-    @io = StringIO.new("this>is>an>example")
-  end
-
-  it "returns the data read till the next occurrence of the passed separator" do
-    @io.gets(">").should == "this>"
-    @io.gets(">").should == "is>"
-    @io.gets(">").should == "an>"
-    @io.gets(">").should == "example"
-  end
-
-  it "sets $_ to the read content" do
-    @io.gets(">")
-    $_.should == "this>"
-    @io.gets(">")
-    $_.should == "is>"
-    @io.gets(">")
-    $_.should == "an>"
-    @io.gets(">")
-    $_.should == "example"
-    @io.gets(">")
-    $_.should be_nil
-  end
-
-  it "accepts string as separator" do
-    @io.gets("is>")
-    $_.should == "this>"
-    @io.gets("an>")
-    $_.should == "is>an>"
-    @io.gets("example")
-    $_.should == "example"
-    @io.gets("ple")
-    $_.should be_nil
-  end
-
-  it "updates self's lineno by one" do
-    @io.gets(">")
-    @io.lineno.should eql(1)
-
-    @io.gets(">")
-    @io.lineno.should eql(2)
-
-    @io.gets(">")
-    @io.lineno.should eql(3)
-  end
-
-  it "returns the next paragraph when the passed separator is an empty String" do
-    io = StringIO.new("this is\n\nan example")
-    io.gets("").should == "this is\n\n"
-    io.gets("").should == "an example"
-  end
-
-  it "returns the remaining content starting at the current position when passed nil" do
-    io = StringIO.new("this is\n\nan example")
-    io.pos = 5
-    io.gets(nil).should == "is\n\nan example"
-  end
+describe "StringIO#gets" do
+  describe "when passed [separator]" do
+    it_behaves_like :stringio_gets_separator, :gets
 
-  it "tries to convert the passed separator to a String using #to_str" do
-    obj = mock('to_str')
-    obj.should_receive(:to_str).and_return(">")
-    @io.gets(obj).should == "this>"
-  end
-end
-
-describe "StringIO#gets when passed no argument" do
-  before :each do
-    @io = StringIO.new("this is\nan example\nfor StringIO#gets")
-  end
+    it "returns nil if self is at the end" do
+      @io = StringIO.new("this>is>an>example")
 
-  it "returns the data read till the next occurrence of $/ or till eof" do
-    @io.gets.should == "this is\n"
-
-    begin
-      old_sep = $/
-      suppress_warning {$/ = " "}
-      @io.gets.should == "an "
-      @io.gets.should == "example\nfor "
-      @io.gets.should == "StringIO#gets"
-    ensure
-      suppress_warning {$/ = old_sep}
+      @io.pos = 36
+      @io.gets(">").should be_nil
+      @io.gets(">").should be_nil
     end
   end
 
-  it "sets $_ to the read content" do
-    @io.gets
-    $_.should == "this is\n"
-    @io.gets
-    $_.should == "an example\n"
-    @io.gets
-    $_.should == "for StringIO#gets"
-    @io.gets
-    $_.should be_nil
-  end
-
-  it "updates self's position" do
-    @io.gets
-    @io.pos.should eql(8)
-
-    @io.gets
-    @io.pos.should eql(19)
-
-    @io.gets
-    @io.pos.should eql(36)
-  end
-
-  it "updates self's lineno" do
-    @io.gets
-    @io.lineno.should eql(1)
-
-    @io.gets
-    @io.lineno.should eql(2)
-
-    @io.gets
-    @io.lineno.should eql(3)
-  end
-
-  it "returns nil if self is at the end" do
-    @io.pos = 36
-    @io.gets.should be_nil
-    @io.gets.should be_nil
-  end
-end
-
-describe "StringIO#gets when passed [limit]" do
-  before :each do
-    @io = StringIO.new("this>is>an>example")
-  end
-
-  it "returns the data read until the limit is met" do
-    @io.gets(4).should == "this"
-    @io.gets(3).should == ">is"
-    @io.gets(5).should == ">an>e"
-    @io.gets(6).should == "xample"
-  end
-
-  it "sets $_ to the read content" do
-    @io.gets(4)
-    $_.should == "this"
-    @io.gets(3)
-    $_.should == ">is"
-    @io.gets(5)
-    $_.should == ">an>e"
-    @io.gets(6)
-    $_.should == "xample"
-    @io.gets(3)
-    $_.should be_nil
-  end
-
-  it "updates self's lineno by one" do
-    @io.gets(3)
-    @io.lineno.should eql(1)
-
-    @io.gets(3)
-    @io.lineno.should eql(2)
-
-    @io.gets(3)
-    @io.lineno.should eql(3)
-  end
-
-  it "tries to convert the passed limit to an Integer using #to_int" do
-    obj = mock('to_int')
-    obj.should_receive(:to_int).and_return(4)
-    @io.gets(obj).should == "this"
-  end
-
-  it "returns a blank string when passed a limit of 0" do
-    @io.gets(0).should == ""
-  end
-
-  it "ignores it when passed a negative limit" do
-    @io.gets(-4).should == "this>is>an>example"
-  end
-end
+  describe "when passed [limit]" do
+    it_behaves_like :stringio_gets_limit, :gets
 
-describe "StringIO#gets when passed [separator] and [limit]" do
-  before :each do
-    @io = StringIO.new("this>is>an>example")
-  end
-
-  it "returns the data read until the limit is consumed or the separator is met" do
-    @io.gets('>', 8).should == "this>"
-    @io.gets('>', 2).should == "is"
-    @io.gets('>', 10).should == ">"
-    @io.gets('>', 6).should == "an>"
-    @io.gets('>', 5).should == "examp"
-  end
+    it "returns nil if self is at the end" do
+      @io = StringIO.new("this>is>an>example")
 
-  it "sets $_ to the read content" do
-    @io.gets('>', 8)
-    $_.should == "this>"
-    @io.gets('>', 2)
-    $_.should == "is"
-    @io.gets('>', 10)
-    $_.should == ">"
-    @io.gets('>', 6)
-    $_.should == "an>"
-    @io.gets('>', 5)
-    $_.should == "examp"
+      @io.pos = 36
+      @io.gets(3).should be_nil
+      @io.gets(3).should be_nil
+    end
   end
 
-  it "updates self's lineno by one" do
-    @io.gets('>', 3)
-    @io.lineno.should eql(1)
+  describe "when passed [separator] and [limit]" do
+    it_behaves_like :stringio_gets_separator_and_limit, :gets
 
-    @io.gets('>', 3)
-    @io.lineno.should eql(2)
+    it "returns nil if self is at the end" do
+      @io = StringIO.new("this>is>an>example")
 
-    @io.gets('>', 3)
-    @io.lineno.should eql(3)
+      @io.pos = 36
+      @io.gets(">", 3).should be_nil
+      @io.gets(">", 3).should be_nil
+    end
   end
 
-  it "tries to convert the passed separator to a String using #to_str" do
-    obj = mock('to_str')
-    obj.should_receive(:to_str).and_return('>')
-    @io.gets(obj, 5).should == "this>"
-  end
+  describe "when passed no argument" do
+    it_behaves_like :stringio_gets_no_argument, :gets
 
-  it "does not raise TypeError if passed separator is nil" do
-    @io.gets(nil, 5).should == "this>"
-  end
+    it "returns nil if self is at the end" do
+      @io = StringIO.new("this>is>an>example")
 
-  it "tries to convert the passed limit to an Integer using #to_int" do
-    obj = mock('to_int')
-    obj.should_receive(:to_int).and_return(5)
-    @io.gets('>', obj).should == "this>"
+      @io.pos = 36
+      @io.gets.should be_nil
+      @io.gets.should be_nil
+    end
   end
-end
-
-describe "StringIO#gets when in write-only mode" do
-  it "raises an IOError" do
-    io = StringIO.new(+"xyz", "w")
-    -> { io.gets }.should raise_error(IOError)
 
-    io = StringIO.new("xyz")
-    io.close_read
-    -> { io.gets }.should raise_error(IOError)
+  describe "when passed [chomp]" do
+    it_behaves_like :stringio_gets_chomp, :gets
   end
-end
 
-describe "StringIO#gets when passed [chomp]" do
-  it "returns the data read without a trailing newline character" do
-    io = StringIO.new("this>is>an>example\n")
-    io.gets(chomp: true).should == "this>is>an>example"
+  describe "when in write-only mode" do
+    it_behaves_like :stringio_gets_write_only, :gets
   end
 end