spec/lib/function_spec.rb in dydx-0.1.3 vs spec/lib/function_spec.rb in dydx-0.1.4

@@ -1,39 +1,65 @@
 require 'spec_helper'
 
-describe Dydx:Function do
-  # TODO: refactor
-  it{ expect(f(x, y)).to eq(f(x, y)) }
-  it{ expect(f(x, y)).to eq($f) }
-  it{ expect(f(x, y).algebra).to be_nil }
-  it{ expect(f(x, y).vars).to eq([:x, :y]) }
-  it{ expect{f(x, y, z)}.to raise_error(ArgumentError) }
-  it{ expect{f(x)}.to raise_error(ArgumentError) }
-  it{ expect(f(x, y) <= x * y ).to eq(f(x, y)) }
-  it{ expect(f(x, y)).to eq(f(x, y)) }
-  it{ expect(f(x, y)).to eq($f) }
-  it{ expect(f(x, y).algebra).to eq(x * y) }
-  it{ expect(f(x, y)).to eq(x * y) }
-  it{ expect(eval(f(x, y).to_s)).to eq(f(x, y)) }
-  it{ expect(f(x, y)).to eq(eval(f(x, y).to_s)) }
-  it{ expect(f(a, b)).to eq(a * b) }
-  it{ expect(f(2, 3)).to eq(6) }
-  it{ expect(f(a + b, c)).to eq((a + b) * c) }
-  it{ expect(d/dx(f(x, y))).to eq(y) }
-  it{ expect(d/dy(f(x, y))).to eq(x) }
-  it{ expect(d/dz(f(x, y))).to eq(0) }
+describe Dydx::Function do
+  before { reset }
 
-  it{ expect(g(a, b) <= f(a + b, b)).to eq(g(a, b)) }
-  it{ expect(g(a, b)).to eq($g) }
-  it{ expect(g(2, 3)).to eq(15) }
+  it 'ex1' do
+    expect(f(x, y)).to eq(f(x, y))
+    expect(f(x, y)).to eq($f)
+    expect(f(x, y).algebra).to be_nil
+    expect(f(x, y).vars).to eq([:x, :y])
+    expect { f(x, y, z) }.to raise_error(ArgumentError)
+    expect { f(x) }.to raise_error(ArgumentError)
+  end
 
-  it{ expect(h(a, b, c) <= d/db(g(a, b))).to eq(h(a, b, c)) }
-  it{ expect(h(a, b, c) <= d/db(g(a, b))).to eq($h) }
-  it{ expect(h(a, b, c)).to eq(( a + ( 2 * b ) )) }
-  it{ expect(h(a, b, c).algebra).to eq(( a + ( 2 * b ) )) }
+  it 'ex2' do
+    expect(f(x, y) <= x * y ).to eq(f(x, y))
+    expect(f(x, y)).to eq(f(x, y))
+    expect(f(x, y)).to eq($f)
+    expect(f(x, y).algebra).to eq(x * y)
+    expect(f(x, y)).to eq(x * y)
+    expect(f(x, y)).to eq(eval(f(x, y).to_s))
+    expect(f(a, b)).to eq(a * b)
+    expect(f(2, x)).to eq(2 * x)
+    expect(f(2, 3)).to eq(6)
+    expect(f(a + b, c)).to eq((a + b) * c)
+    expect(d/dx(f(x, y))).to eq(y)
+    expect(d/dy(f(x, y))).to eq(x)
+    expect(d/dz(f(x, y))).to eq(0)
+  end
 
-  it 'ex.4' do
-    $f = nil
+  it 'ex3' do
+    f(x, y) <= x * y
+    g(a, b) <= f(a + b, b)
+    expect(g(a, b)).to eq((a + b) * b)
+    expect(g(a, 3)).to eq(9 + 3 * a)
+    expect(g(2, 3)).to eq(15)
+  end
+
+  it 'ex4' do
+    f(a, b) <= (a + b) * b
+    h(a, b, c) <= d/db(f(a, b))
+    expect(h(a, b, c)).to eq(( a + ( 2 * b ) ))
+    expect(h(a, b, c).algebra).to eq(( a + ( 2 * b ) ))
+  end
+
+  it 'ex5' do
     f(x) <= log(x)
-    expect(f(a)).to eq(log(a))
+    expect(f(e)).to eq(1)
+    expect(f(0)).to eq(-oo)
+    expect(f(y)).to eq(log(y))
+
+    g(x) <= d/dx(f(x))
+    expect(g(1)).to eq(1)
+  end
+
+  it 'ex6' do
+    f(x) <= sin(x)
+    expect(f(pi)).to eq(0)
+    expect(f(pi / 2)).to eq(1)
+    expect(f(y)).to eq(sin(y))
+
+    g(x) <= d/dx(f(x))
+    expect(g(pi)).to eq(-1)
   end
 end