Add specs for all of IO::Buffer constructors

core/io/buffer/external_spec.rb

@@ -6,103 +6,18 @@
     @buffer = nil
   end
 
-  context "with a buffer created with .new" do
-    it "is false for an internal buffer" do
-      @buffer = IO::Buffer.new(4)
-      @buffer.external?.should be_false
-    end
-
-    it "is false for a mapped buffer" do
-      @buffer = IO::Buffer.new(4, IO::Buffer::MAPPED)
-      @buffer.external?.should be_false
-    end
-  end
-
-  context "with a file-backed buffer created with .map" do
-    it "is true for a regular mapping" do
-      File.open(__FILE__, "r") do |file|
-        @buffer = IO::Buffer.map(file, nil, 0, IO::Buffer::READONLY)
-        @buffer.external?.should be_true
-      end
-    end
-
-    ruby_version_is "3.3" do
-      it "is false for a private mapping" do
-        File.open(__FILE__, "r") do |file|
-          @buffer = IO::Buffer.map(file, nil, 0, IO::Buffer::READONLY | IO::Buffer::PRIVATE)
-          @buffer.external?.should be_false
-        end
-      end
-    end
-  end
-
-  context "with a String-backed buffer created with .for" do
-    it "is true for a buffer created without a block" do
-      @buffer = IO::Buffer.for("test")
-      @buffer.external?.should be_true
-    end
-
-    it "is true for a buffer created with a block" do
-      IO::Buffer.for(+"test") do |buffer|
-        buffer.external?.should be_true
-      end
-    end
+  it "is true for a buffer with externally-managed memory" do
+    @buffer = IO::Buffer.for("string")
+    @buffer.external?.should be_true
   end
 
-  ruby_version_is "3.3" do
-    context "with a String-backed buffer created with .string" do
-      it "is true" do
-        IO::Buffer.string(4) do |buffer|
-          buffer.external?.should be_true
-        end
-      end
-    end
+  it "is false for a buffer with self-managed memory" do
+    @buffer = IO::Buffer.new(12, IO::Buffer::MAPPED)
+    @buffer.external?.should be_false
   end
 
-  # Always false for slices
-  context "with a slice of a buffer" do
-    context "created with .new" do
-      it "is false when slicing an internal buffer" do
-        @buffer = IO::Buffer.new(4)
-        @buffer.slice.external?.should be_false
-      end
-
-      it "is false when slicing a mapped buffer" do
-        @buffer = IO::Buffer.new(4, IO::Buffer::MAPPED)
-        @buffer.slice.external?.should be_false
-      end
-    end
-
-    context "created with .map" do
-      it "is false" do
-        File.open(__FILE__, "r") do |file|
-          @buffer = IO::Buffer.map(file, nil, 0, IO::Buffer::READONLY)
-          @buffer.slice.external?.should be_false
-        end
-      end
-    end
-
-    context "created with .for" do
-      it "is false when slicing a buffer created without a block" do
-        @buffer = IO::Buffer.for("test")
-        @buffer.slice.external?.should be_false
-      end
-
-      it "is false when slicing a buffer created with a block" do
-        IO::Buffer.for(+"test") do |buffer|
-          buffer.slice.external?.should be_false
-        end
-      end
-    end
-
-    ruby_version_is "3.3" do
-      context "created with .string" do
-        it "is false" do
-          IO::Buffer.string(4) do |buffer|
-            buffer.slice.external?.should be_false
-          end
-        end
-      end
-    end
+  it "is false for a null buffer" do
+    @buffer = IO::Buffer.new(0)
+    @buffer.external?.should be_false
   end
 end

core/io/buffer/for_spec.rb

@@ -0,0 +1,115 @@
+require_relative '../../../spec_helper'
+
+describe "IO::Buffer.for" do
+  before :each do
+    @string = +"för striñg"
+  end
+
+  after :each do
+    @buffer&.free
+    @buffer = nil
+  end
+
+  context "without a block" do
+    it "copies string's contents, creating a separate read-only buffer" do
+      @buffer = IO::Buffer.for(@string)
+
+      @buffer.size.should == @string.bytesize
+      @buffer.get_string.should == @string.b
+
+      @string[0] = "d"
+      @buffer.get_string(0, 1).should == "f".b
+
+      -> { @buffer.set_string("d") }.should raise_error(IO::Buffer::AccessError, "Buffer is not writable!")
+    end
+
+    ruby_version_is ""..."3.3" do
+      it "creates an external, read-only buffer" do
+        @buffer = IO::Buffer.for(@string)
+
+        @buffer.should_not.internal?
+        @buffer.should_not.mapped?
+        @buffer.should.external?
+
+        @buffer.should_not.empty?
+        @buffer.should_not.null?
+
+        @buffer.should_not.shared?
+        @buffer.should.readonly?
+
+        @buffer.should_not.locked?
+        @buffer.should.valid?
+      end
+    end
+
+    ruby_version_is "3.3" do
+      it "creates an external, read-only buffer" do
+        @buffer = IO::Buffer.for(@string)
+
+        @buffer.should_not.internal?
+        @buffer.should_not.mapped?
+        @buffer.should.external?
+
+        @buffer.should_not.empty?
+        @buffer.should_not.null?
+
+        @buffer.should_not.shared?
+        @buffer.should_not.private?
+        @buffer.should.readonly?
+
+        @buffer.should_not.locked?
+        @buffer.should.valid?
+      end
+    end
+  end
+
+  context "with a block" do
+    it "returns the last value in the block" do
+      value =
+        IO::Buffer.for(@string) do |buffer|
+          buffer.size * 3
+        end
+      value.should == @string.bytesize * 3
+    end
+
+    it "frees the buffer at the end of the block" do
+      IO::Buffer.for(@string) do |buffer|
+        @buffer = buffer
+        @buffer.should_not.null?
+      end
+      @buffer.should.null?
+    end
+
+    context "if string is not frozen" do
+      it "creates a modifiable string-backed buffer" do
+        IO::Buffer.for(@string) do |buffer|
+          buffer.size.should == @string.bytesize
+          buffer.get_string.should == @string.b
+
+          buffer.should_not.readonly?
+
+          buffer.set_string("ghost shell")
+          @string.should == "ghost shellg"
+        end
+      end
+
+      it "locks the original string to prevent modification" do
+        IO::Buffer.for(@string) do |_buffer|
+          -> { @string[0] = "t" }.should raise_error(RuntimeError, "can't modify string; temporarily locked")
+        end
+        @string[1] = "u"
+        @string.should == "fur striñg"
+      end
+    end
+
+    context "if string is frozen" do
+      it "creates a read-only string-backed buffer" do
+        IO::Buffer.for(@string.freeze) do |buffer|
+          buffer.should.readonly?
+
+          -> { buffer.set_string("ghost shell") }.should raise_error(IO::Buffer::AccessError, "Buffer is not writable!")
+        end
+      end
+    end
+  end
+end

core/io/buffer/initialize_spec.rb

@@ -12,42 +12,62 @@
     @buffer.each(:U8).should.all? { |_offset, value| value.eql?(0) }
   end
 
-  it "creates a buffer with default state" do
-    @buffer = IO::Buffer.new
-    @buffer.should_not.shared?
-    @buffer.should_not.readonly?
+  ruby_version_is ""..."3.3" do
+    it "creates a buffer with default state" do
+      @buffer = IO::Buffer.new
+
+      @buffer.should_not.shared?
+      @buffer.should_not.readonly?
+
+      @buffer.should_not.empty?
+      @buffer.should_not.null?
+
+      @buffer.should_not.locked?
+      @buffer.should.valid?
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "creates a buffer with default state" do
+      @buffer = IO::Buffer.new
 
-    @buffer.should_not.empty?
-    @buffer.should_not.null?
+      @buffer.should_not.external?
 
-    # This is run-time state, set by #locked.
-    @buffer.should_not.locked?
+      @buffer.should_not.shared?
+      @buffer.should_not.private?
+      @buffer.should_not.readonly?
+
+      @buffer.should_not.empty?
+      @buffer.should_not.null?
+
+      @buffer.should_not.locked?
+      @buffer.should.valid?
+    end
   end
 
   context "with size argument" do
     it "creates a new internal buffer if size is less than IO::Buffer::PAGE_SIZE" do
       size = IO::Buffer::PAGE_SIZE - 1
       @buffer = IO::Buffer.new(size)
       @buffer.size.should == size
+      @buffer.should_not.empty?
+
       @buffer.should.internal?
       @buffer.should_not.mapped?
-      @buffer.should_not.empty?
     end
 
     it "creates a new mapped buffer if size is greater than or equal to IO::Buffer::PAGE_SIZE" do
       size = IO::Buffer::PAGE_SIZE
       @buffer = IO::Buffer.new(size)
       @buffer.size.should == size
+      @buffer.should_not.empty?
+
       @buffer.should_not.internal?
       @buffer.should.mapped?
-      @buffer.should_not.empty?
     end
 
     it "creates a null buffer if size is 0" do
       @buffer = IO::Buffer.new(0)
-      @buffer.size.should.zero?
-      @buffer.should_not.internal?
-      @buffer.should_not.mapped?
       @buffer.should.null?
       @buffer.should.empty?
     end
@@ -77,6 +97,29 @@
       @buffer.should_not.empty?
     end
 
+    it "allows extra flags" do
+      @buffer = IO::Buffer.new(10, IO::Buffer::INTERNAL | IO::Buffer::SHARED | IO::Buffer::READONLY)
+      @buffer.should.internal?
+      @buffer.should.shared?
+      @buffer.should.readonly?
+    end
+
+    it "ignores flags if size is 0" do
+      @buffer = IO::Buffer.new(0, 0xffff)
+      @buffer.should.null?
+      @buffer.should.empty?
+
+      @buffer.should_not.internal?
+      @buffer.should_not.mapped?
+      @buffer.should_not.external?
+
+      @buffer.should_not.shared?
+      @buffer.should_not.readonly?
+
+      @buffer.should_not.locked?
+      @buffer.should.valid?
+    end
+
     it "raises IO::Buffer::AllocationError if neither IO::Buffer::MAPPED nor IO::Buffer::INTERNAL is given" do
       -> { IO::Buffer.new(10, IO::Buffer::READONLY) }.should raise_error(IO::Buffer::AllocationError, "Could not allocate buffer!")
       -> { IO::Buffer.new(10, 0) }.should raise_error(IO::Buffer::AllocationError, "Could not allocate buffer!")