Add Property Based Tests

Author: kennyp

demo_05/fib_test.go

@@ -7,33 +7,39 @@ import (
 
 func TestFibRecursive(t *testing.T) {
 	tests := map[int]int{
-		0: 0,
-		1: 1,
-		2: 1,
-		3: 2,
-		4: 3,
-		5: 5,
+		0:  0,
+		1:  1,
+		2:  1,
+		3:  2,
+		4:  3,
+		5:  5,
+		10: 55,
 	}
 	for i, v := range tests {
-		if f := FibRecursive(i); f != v {
-			t.Fatalf("FibRecursive(%v) == %v : expected %v", i, f, v)
-		}
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			if f := FibRecursive(i); f != v {
+				t.Fatalf("FibRecursive(%v) == %v : expected %v", i, f, v)
+			}
+		})
 	}
 }
 
 func TestFibCache(t *testing.T) {
 	tests := map[int]int{
-		0: 0,
-		1: 1,
-		2: 1,
-		3: 2,
-		4: 3,
-		5: 5,
+		0:  0,
+		1:  1,
+		2:  1,
+		3:  2,
+		4:  3,
+		5:  5,
+		10: 55,
 	}
 	for i, v := range tests {
-		if f := FibCache(i); f != v {
-			t.Fatalf("FibCache(%v) == %v : expected %v", i, f, v)
-		}
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			if f := FibCache(i); f != v {
+				t.Fatalf("FibCache(%v) == %v : expected %v", i, f, v)
+			}
+		})
 	}
 }
 

demo_06/mystrings.go

@@ -0,0 +1,32 @@
+package mystrings
+
+const (
+	LowerCaseA = 97
+	UpperCaseZ = 90
+)
+
+func Lower(s string) string {
+	input := []rune(s)
+	out := make([]rune, len(input))
+	for i, r := range input {
+		if r <= UpperCaseZ {
+			out[i] = r + 32
+		} else {
+			out[i] = r
+		}
+	}
+	return string(out)
+}
+
+func Upper(s string) string {
+	input := []rune(s)
+	out := make([]rune, len(input))
+	for i, r := range input {
+		if r >= LowerCaseA {
+			out[i] = r - 32
+		} else {
+			out[i] = r
+		}
+	}
+	return string(out)
+}

demo_06/mystrings_test.go

@@ -0,0 +1,87 @@
+package mystrings
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/leanovate/gopter"
+	"github.com/leanovate/gopter/gen"
+	"github.com/leanovate/gopter/prop"
+)
+
+func TestLower(t *testing.T) {
+	ts := map[string]string{
+		"HELLO":   "hello",
+		"WORLD[]": "world[]",
+		"":        "",
+	}
+
+	for s, v := range ts {
+		t.Run(s, func(t *testing.T) {
+			if r := Lower(s); r != v {
+				t.Fatalf("%v != %v", r, v)
+			}
+		})
+	}
+}
+
+func TestUpper(t *testing.T) {
+	ts := map[string]string{
+		"hello":      "HELLO",
+		"first-name": "FIRST-NAME",
+		"":           "",
+	}
+
+	for s, v := range ts {
+		t.Run(s, func(t *testing.T) {
+			if r := Upper(s); r != v {
+				t.Fatalf("%v != %v", r, v)
+			}
+		})
+	}
+}
+
+func TestLowerMatchesStrings(t *testing.T) {
+	properties := gopter.NewProperties(nil)
+	properties.Property("my implimentation matches strings.Lower", prop.ForAll(
+		func(s string) bool {
+			if r := Lower(s); r != strings.ToLower(s) {
+				t.Logf("Lower(%+v) == %+v", s, r)
+				return false
+			}
+
+			return true
+		},
+		genStringRange('A', 'z'),
+	))
+	properties.TestingRun(t)
+}
+
+func TestUppoerMatchesStrings(t *testing.T) {
+	properties := gopter.NewProperties(nil)
+	properties.Property("my implimentation matches strings.Upper", prop.ForAll(
+		func(s string) bool {
+			if r := Upper(s); r != strings.ToUpper(s) {
+				t.Logf("Upper(%+v) == %+v", s, r)
+				return false
+			}
+
+			return true
+		},
+		genStringRange('A', 'z'),
+		//genStringRange(' ', '~'),
+	))
+	properties.TestingRun(t)
+}
+
+func genStringRange(min, max rune) gopter.Gen {
+	return gopter.DeriveGen(
+		func(rs []rune) string {
+			return string(rs)
+		},
+		func(s string) []rune {
+			return []rune(s)
+		},
+		gen.SliceOf(gen.RuneRange(min, max)),
+	)
+}

go.mod

@@ -1,3 +1,5 @@
 module github.com/gsinghkular/go_test_demo
 
 go 1.17
+
+require github.com/leanovate/gopter v0.2.9

go.sum

@@ -0,0 +1,2 @@
+github.com/leanovate/gopter v0.2.9 h1:fQjYxZaynp97ozCzfOyOuAGOU4aU/z37zf/tOujFk7c=
+github.com/leanovate/gopter v0.2.9/go.mod h1:U2L/78B+KVFIx2VmW6onHJQzXtFb+p5y3y2Sh+Jxxv8=