GUID tests to use t.Run (#256)

Switched to subtests using `t.Run()` for GUID testing, rather than using
log statements to demarcate different tests.

Added `.String` to GUID `Variant` and `Version` using
`golang.org/x/tools/cmd/stringer`.

Added `tools.go` to version `stringer` in go.mod and allow
`go generate ./...` to be run without needing a `go get` call.
Based off of [go wiki](https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module)
recommendation.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

pkg/guid/guid.go

@@ -14,17 +14,19 @@ import (
 	"strconv"
 )
 
+//go:generate go run golang.org/x/tools/cmd/stringer -type=Variant -trimprefix=Variant -linecomment
+
 // Variant specifies which GUID variant (or "type") of the GUID. It determines
 // how the entirety of the rest of the GUID is interpreted.
 type Variant uint8
 
-// The variants specified by RFC 4122.
+// The variants specified by RFC 4122 section 4.1.1.
 const (
 	// VariantUnknown specifies a GUID variant which does not conform to one of
 	// the variant encodings specified in RFC 4122.
 	VariantUnknown Variant = iota
 	VariantNCS
-	VariantRFC4122
+	VariantRFC4122 // RFC 4122
 	VariantMicrosoft
 	VariantFuture
 )
@@ -34,6 +36,10 @@ const (
 // hash of an input string.
 type Version uint8
 
+func (v Version) String() string {
+	return strconv.FormatUint(uint64(v), 10)
+}
+
 var _ = (encoding.TextMarshaler)(GUID{})
 var _ = (encoding.TextUnmarshaler)(&GUID{})
 

pkg/guid/guid_test.go

@@ -46,27 +46,29 @@ func Test_Variant(t *testing.T) {
 		{mustFromString(t, "f5cbc1a9-4cba-45a0-ffdd-b6761fc7dcc0"), VariantFuture},
 	}
 	for _, tc := range testCases {
-		actualVariant := tc.g.Variant()
-		if actualVariant != tc.v {
-			t.Fatalf("Variant is not correct.\nExpected: %d\nActual: %d\nGUID: %s", tc.v, actualVariant, tc.g)
-		}
+		t.Run(tc.v.String()+"/"+tc.g.String(), func(t *testing.T) {
+			actualVariant := tc.g.Variant()
+			if actualVariant != tc.v {
+				t.Fatalf("Variant is not correct.\nExpected: %d\nActual: %d\nGUID: %s", tc.v, actualVariant, tc.g)
+			}
+		})
 	}
 }
 
 func Test_SetVariant(t *testing.T) {
-	testCases := []Variant{
-		VariantNCS,
-		VariantRFC4122,
-		VariantMicrosoft,
-		VariantFuture,
-	}
 	g := mustFromString(t, "f5cbc1a9-4cba-45a0-bfdd-b6761fc7dcc0")
-	for _, tc := range testCases {
-		t.Logf("Test case: %d", tc)
-		g.setVariant(tc)
-		if g.Variant() != tc {
-			t.Fatalf("Variant is incorrect.\nExpected: %d\nActual: %d", tc, g.Variant())
+	for i := 0; i < len(_Variant_index)-1; i++ {
+		v := Variant(i)
+		if v == VariantUnknown {
+			// Unknown is not a valid variant
+			continue
 		}
+		t.Run(v.String(), func(t *testing.T) {
+			g.setVariant(v)
+			if g.Variant() != v {
+				t.Fatalf("Variant is incorrect.\nExpected: %d\nActual: %d", v, g.Variant())
+			}
+		})
 	}
 }
 
@@ -83,22 +85,25 @@ func Test_Version(t *testing.T) {
 		{mustFromString(t, "f5cbc1a9-4cba-55a0-0fdd-b6761fc7dcc0"), 5},
 	}
 	for _, tc := range testCases {
-		actualVersion := tc.g.Version()
-		if actualVersion != tc.v {
-			t.Fatalf("Version is not correct.\nExpected: %d\nActual: %d\nGUID: %s", tc.v, actualVersion, tc.g)
-		}
+		t.Run(tc.v.String()+"-"+tc.g.String(), func(t *testing.T) {
+			actualVersion := tc.g.Version()
+			if actualVersion != tc.v {
+				t.Fatalf("Version is not correct.\nExpected: %d\nActual: %d\nGUID: %s", tc.v, actualVersion, tc.g)
+			}
+		})
 	}
 }
 
 func Test_SetVersion(t *testing.T) {
 	g := mustFromString(t, "f5cbc1a9-4cba-45a0-bfdd-b6761fc7dcc0")
 	for tc := 0; tc < 16; tc++ {
-		t.Logf("Test case: %d", tc)
 		v := Version(tc)
-		g.setVersion(v)
-		if g.Version() != v {
-			t.Fatalf("Version is incorrect.\nExpected: %d\nActual: %d", v, g.Version())
-		}
+		t.Run(v.String(), func(t *testing.T) {
+			g.setVersion(v)
+			if g.Version() != v {
+				t.Fatalf("Version is incorrect.\nExpected: %d\nActual: %d", v, g.Version())
+			}
+		})
 	}
 }
 
@@ -160,10 +165,12 @@ func Test_V5KnownValues(t *testing.T) {
 		},
 	}
 	for _, tc := range testCases {
-		g := mustNewV5(t, tc.ns, []byte(tc.name))
-		if g != tc.g {
-			t.Fatalf("GUIDs are not equal.\nExpected: %s\nActual: %s", tc.g, g)
-		}
+		t.Run(tc.name, func(t *testing.T) {
+			g := mustNewV5(t, tc.ns, []byte(tc.name))
+			if g != tc.g {
+				t.Fatalf("GUIDs are not equal.\nExpected: %s\nActual: %s", tc.g, g)
+			}
+		})
 	}
 }
 

pkg/guid/variant_string.go

@@ -0,0 +1,27 @@
+// Code generated by "stringer -type=Variant -trimprefix=Variant -linecomment"; DO NOT EDIT.
+
+package guid
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[VariantUnknown-0]
+	_ = x[VariantNCS-1]
+	_ = x[VariantRFC4122-2]
+	_ = x[VariantMicrosoft-3]
+	_ = x[VariantFuture-4]
+}
+
+const _Variant_name = "UnknownNCSRFC 4122MicrosoftFuture"
+
+var _Variant_index = [...]uint8{0, 7, 10, 18, 27, 33}
+
+func (i Variant) String() string {
+	if i >= Variant(len(_Variant_index)-1) {
+		return "Variant(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _Variant_name[_Variant_index[i]:_Variant_index[i+1]]
+}