1 files changed, 68 insertions, 0 deletions
diff --git a/spec/ruby/core/exception/backtrace_spec.rb b/spec/ruby/core/exception/backtrace_spec.rb
new file mode 100644
index 0000000000..2d115e9b2f
--- /dev/null
+++ b/spec/ruby/core/exception/backtrace_spec.rb
@@ -0,0 +1,68 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/common', __FILE__)
+
+describe "Exception#backtrace" do
+  before :each do
+    @backtrace = ExceptionSpecs::Backtrace.backtrace
+  end
+
+  it "returns nil if no backtrace was set" do
+    Exception.new.backtrace.should be_nil
+  end
+
+  it "returns an Array" do
+    @backtrace.should be_an_instance_of(Array)
+  end
+
+  it "sets each element to a String" do
+    @backtrace.each {|l| l.should be_an_instance_of(String)}
+  end
+
+  it "includes the filename of the location where self raised in the first element" do
+    @backtrace.first.should =~ /common\.rb/
+  end
+
+  it "includes the line number of the location where self raised in the first element" do
+    @backtrace.first.should =~ /:7:in /
+  end
+
+  it "includes the name of the method from where self raised in the first element" do
+    @backtrace.first.should =~ /in `backtrace'/
+  end
+
+  it "includes the filename of the location immediately prior to where self raised in the second element" do
+    @backtrace[1].should =~ /backtrace_spec\.rb/
+  end
+
+  it "includes the line number of the location immediately prior to where self raised in the second element" do
+    @backtrace[1].should =~ /:6(:in )?/
+  end
+
+  it "contains lines of the same format for each prior position in the stack" do
+    @backtrace[2..-1].each do |line|
+      # This regexp is deliberately imprecise to account for the need to abstract out
+      # the paths of the included mspec files and the desire to avoid specifying in any
+      # detail what the in `...' portion looks like.
+      line.should =~ /^[^ ]+\:\d+(:in `[^`]+')?$/
+    end
+  end
+
+  it "produces a backtrace for an exception captured using $!" do
+    exception = begin
+      raise
+    rescue RuntimeError
+      $!
+    end
+
+    exception.backtrace.first.should =~ /backtrace_spec/
+  end
+
+  it "returns an Array that can be updated" do
+    begin
+      raise
+    rescue RuntimeError => e
+      e.backtrace.unshift "backtrace first"
+      e.backtrace[0].should == "backtrace first"
+    end
+  end
+end