1 files changed, 69 insertions, 0 deletions
diff --git a/spec/ruby/core/string/to_f_spec.rb b/spec/ruby/core/string/to_f_spec.rb
new file mode 100644
index 0000000000..8454651ab2
--- /dev/null
+++ b/spec/ruby/core/string/to_f_spec.rb
@@ -0,0 +1,69 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes.rb', __FILE__)
+
+# src.scan(/[+-]?[\d_]+\.[\d_]+(e[+-]?[\d_]+)?\b|[+-]?[\d_]+e[+-]?[\d_]+\b/i)
+
+describe "String#to_f" do
+  it "treats leading characters of self as a floating point number" do
+   "123.45e1".to_f.should == 1234.5
+   "45.67 degrees".to_f.should == 45.67
+   "0".to_f.should == 0.0
+   "123.45e1".to_f.should == 1234.5
+
+   ".5".to_f.should == 0.5
+   ".5e1".to_f.should == 5.0
+   "5e".to_f.should == 5.0
+   "5E".to_f.should == 5.0
+  end
+
+  it "treats special float value strings as characters" do
+    "NaN".to_f.should == 0
+    "Infinity".to_f.should == 0
+    "-Infinity".to_f.should == 0
+  end
+
+  it "allows for varying case" do
+    "123.45e1".to_f.should == 1234.5
+    "123.45E1".to_f.should == 1234.5
+  end
+
+  it "allows for varying signs" do
+    "+123.45e1".to_f.should == +123.45e1
+    "-123.45e1".to_f.should == -123.45e1
+    "123.45e+1".to_f.should == 123.45e+1
+    "123.45e-1".to_f.should == 123.45e-1
+    "+123.45e+1".to_f.should == +123.45e+1
+    "+123.45e-1".to_f.should == +123.45e-1
+    "-123.45e+1".to_f.should == -123.45e+1
+    "-123.45e-1".to_f.should == -123.45e-1
+  end
+
+  it "allows for underscores, even in the decimal side" do
+    "1_234_567.890_1".to_f.should == 1_234_567.890_1
+  end
+
+  it "returns 0 for strings with any non-digit in them" do
+    "blah".to_f.should == 0
+    "0b5".to_f.should == 0
+    "0d5".to_f.should == 0
+    "0o5".to_f.should == 0
+    "0xx5".to_f.should == 0
+  end
+
+  it "returns 0 for strings with leading underscores" do
+    "_9".to_f.should == 0
+  end
+
+  it "takes an optional sign" do
+    "-45.67 degrees".to_f.should == -45.67
+    "+45.67 degrees".to_f.should == 45.67
+    "-5_5e-5_0".to_f.should == -55e-50
+    "-".to_f.should == 0.0
+    (1.0 / "-0".to_f).to_s.should == "-Infinity"
+  end
+
+  it "returns 0.0 if the conversion fails" do
+    "bad".to_f.should == 0.0
+    "thx1138".to_f.should == 0.0
+  end
+end