Merge pull request #2616 from herwinw/string_to_f

Import specs of String#to_f

spec/core/string/to_f_spec.rb

@@ -0,0 +1,140 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+# 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
+
+   ".5".to_f.should == 0.5
+   ".5e1".to_f.should == 5.0
+   "5.".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
+    NATFIXME 'it treats special float value strings as characters', exception: SpecFailedException do
+      "NaN".to_f.should == 0
+      "Infinity".to_f.should == 0
+      "-Infinity".to_f.should == 0
+    end
+  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
+    NATFIXME 'it allows for underscores, even in the decimal side', exception: SpecFailedException do
+      "1_234_567.890_1".to_f.should == 1_234_567.890_1
+    end
+  end
+
+  it "returns 0 for strings with leading underscores" do
+    "_9".to_f.should == 0
+  end
+
+  it "stops if the underscore is not followed or preceded by a number" do
+    "1__2".to_f.should == 1.0
+    "1_.2".to_f.should == 1.0
+    "1._2".to_f.should == 1.0
+    "1.2_e2".to_f.should == 1.2
+    "1.2e_2".to_f.should == 1.2
+    "1_x2".to_f.should == 1.0
+    "1x_2".to_f.should == 1.0
+    "+_1".to_f.should == 0.0
+    "-_1".to_f.should == 0.0
+  end
+
+  it "does not allow prefixes to autodetect the base" do
+    "0b10".to_f.should == 0
+    "010".to_f.should == 10
+    "0o10".to_f.should == 0
+    "0d10".to_f.should == 0
+    NATFIXME 'it does not allow prefixes to autodetect the base', exception: SpecFailedException do
+      "0x10".to_f.should == 0
+    end
+  end
+
+  it "treats any non-numeric character other than '.', 'e' and '_' as terminals" do
+    "blah".to_f.should == 0
+    "1b5".to_f.should == 1
+    "1d5".to_f.should == 1
+    "1o5".to_f.should == 1
+    "1xx5".to_f.should == 1
+    "x5".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
+    NATFIXME 'it takes an optional sign', exception: SpecFailedException do
+      "-5_5e-5_0".to_f.should == -55e-50
+    end
+    "-".to_f.should == 0.0
+    (1.0 / "-0".to_f).to_s.should == "-Infinity"
+  end
+
+  it "treats a second 'e' as terminal" do
+    "1.234e1e2".to_f.should == 1.234e1
+  end
+
+  it "treats a second '.' as terminal" do
+    "1.2.3".to_f.should == 1.2
+  end
+
+  it "treats a '.' after an 'e' as terminal" do
+    "1.234e1.9".to_f.should == 1.234e1
+  end
+
+  it "returns 0.0 if the conversion fails" do
+    "bad".to_f.should == 0.0
+    "thx1138".to_f.should == 0.0
+  end
+
+  it "ignores leading and trailing whitespace" do
+    "  1.2".to_f.should == 1.2
+    "1.2  ".to_f.should == 1.2
+    " 1.2 ".to_f.should == 1.2
+    "\t1.2".to_f.should == 1.2
+    "\n1.2".to_f.should == 1.2
+    "\v1.2".to_f.should == 1.2
+    "\f1.2".to_f.should == 1.2
+    "\r1.2".to_f.should == 1.2
+  end
+
+  it "treats non-printable ASCII characters as terminals" do
+    "\0001.2".to_f.should == 0
+    "\0011.2".to_f.should == 0
+    "\0371.2".to_f.should == 0
+    "\1771.2".to_f.should == 0
+    "\2001.2".b.to_f.should == 0
+    "\3771.2".b.to_f.should == 0
+  end
+
+  ruby_version_is "3.2" do
+    it "raises Encoding::CompatibilityError if String is in not ASCII-compatible encoding" do
+      NATFIXME 'Add encoder to to UTF-16', exception: SpecFailedException, message: /code converter not found \(UTF-8 to UTF-16\)/ do
+        -> {
+          '1.2'.encode("UTF-16").to_f
+        }.should raise_error(Encoding::CompatibilityError, "ASCII incompatible encoding: UTF-16")
+      end
+    end
+  end
+end