1 files changed, 38 insertions, 0 deletions
diff --git a/spec/ruby/library/matrix/shared/determinant.rb b/spec/ruby/library/matrix/shared/determinant.rb
new file mode 100644
index 0000000000..47a58c62a6
--- /dev/null
+++ b/spec/ruby/library/matrix/shared/determinant.rb
@@ -0,0 +1,38 @@
+require 'matrix'
+
+describe :determinant, shared: true do
+  it "returns the determinant of a square Matrix" do
+    m = Matrix[ [7,6], [3,9] ]
+    m.send(@method).should == 45
+
+    m = Matrix[ [9, 8], [6,5] ]
+    m.send(@method).should == -3
+
+    m = Matrix[ [9,8,3], [4,20,5], [1,1,1] ]
+    m.send(@method).should == 95
+  end
+
+  it "returns the determinant of a single-element Matrix" do
+    m = Matrix[ [2] ]
+    m.send(@method).should == 2
+  end
+
+  it "returns 1 for an empty Matrix" do
+    m = Matrix[ ]
+    m.send(@method).should == 1
+  end
+
+  it "returns the determinant even for Matrices containing 0 as first entry" do
+    Matrix[[0,1],[1,0]].send(@method).should == -1
+  end
+
+  it "raises an error for rectangular matrices" do
+    lambda {
+      Matrix[[1], [2], [3]].send(@method)
+    }.should raise_error(Matrix::ErrDimensionMismatch)
+
+    lambda {
+      Matrix.empty(3,0).send(@method)
+    }.should raise_error(Matrix::ErrDimensionMismatch)
+  end
+end