Add Number#round specs

spec/std/number_spec.cr

@@ -41,44 +41,67 @@ describe "Number" do
     end
   end
 
-  describe "round" do
-    it "rounds to 0 digits with base 10 from default" do
+  describe "#round" do
+    it "rounds to nearest integer" do
+      5.5.round.should eq(6)
+      0.4.round.should eq(0)
+      -2.8.round.should eq(-3)
+      0.0.round.should eq(0)
+      0.49999999999999994.round.should eq(0)
       -1763.116.round.should eq(-1763)
       753.155.round.should eq(753)
       15.151.round.should eq(15)
     end
 
-    it "10 base" do
+    it "infinity" do
+      Float64::INFINITY.round.infinite?.should eq(1)
+      Float32::INFINITY.round.infinite?.should eq(1)
+      (-Float64::INFINITY).round.infinite?.should eq(-1)
+      (-Float32::INFINITY).round.infinite?.should eq(-1)
+    end
+
+    it "nan" do
+      Float64::NAN.round.nan?.should be_true
+      Float32::NAN.round.nan?.should be_true
+    end
+
+    it "rounds to digits" do
+      5.5.round(0).should eq(6)
+      5.7.round(1).should eq(5.7)
+      1.2345678.round(2).should eq(1.23)
+      123456.78.round(-2).should eq(123500) # rounded up
+      -123456.78.round(-2).should eq(-123500)
+
       -1763.116.round(2).should eq(-1763.12)
       753.155.round(2).should eq(753.16)
       15.151.round(2).should eq(15.15)
-    end
 
-    it "2 base" do
-      -1763.116.round(2, base: 2).should eq(-1763.0)
-      753.155.round(2, base: 2).should eq(753.25)
-      15.159.round(2, base: 2).should eq(15.25)
+      0.8346268.round(-1).should eq(0)
     end
 
-    it "8 base" do
-      -1763.116.round(2, base: 8).should eq(-1763.109375)
-      753.155.round(1, base: 8).should eq(753.125)
-      15.159.round(0, base: 8).should eq(15.0)
+    it { 42.0.round(300).should eq(42.0) }
+
+    pending "edge cases" do
+      42.0.round(308).should eq(42.0)
+      42.0.round(309).should eq(42.0)
+
+      1.0e307.round(2).should eq(1.0e307)
+      0.42.round(2**30).should eq(0.42)
     end
 
     it "preserves type" do
-      123.round(2).should eq(123)
-      123.round(2).should be_a(Int32)
+      1.round.should be_a(Int32)
+      1_u8.round.should be_a(UInt8)
+      1.0_f32.round.should be_a(Float32)
     end
 
-    it "accepts negative precision" do
+    it "negative digits" do
       123.round(-2).should eq(100)
       123.round(-3).should eq(0)
       523.round(-3).should eq(1000)
 
       123.456.round(-2).should eq(100)
       123_456.123456.round(-5).should eq(100_000)
-      753.155.round(-5, base: 2).should eq(768)
     end
 
     it "accepts unsigned precision" do
@@ -92,6 +115,21 @@ describe "Number" do
       1.098765432109876543210987654321.round(21).should eq(1.098765432109876543211)
       6543210987654321.0.round(-15).should eq(7000000000000000.0)
     end
+
+    describe "base" do
+      it "2" do
+        -1763.116.round(2, base: 2).should eq(-1763.0)
+        753.155.round(2, base: 2).should eq(753.25)
+        15.159.round(2, base: 2).should eq(15.25)
+        753.155.round(-5, base: 2).should eq(768)
+      end
+
+      it "8" do
+        -1763.116.round(2, base: 8).should eq(-1763.109375)
+        753.155.round(1, base: 8).should eq(753.125)
+        15.159.round(0, base: 8).should eq(15.0)
+      end
+    end
   end
 
   it "gives the absolute value" do