feat: improve deep copy pattern (#133)

Makefile

@@ -18,7 +18,7 @@ TMPDIR ?= /tmp
 # Setup default go-make installation flags.
 INSTALL_FLAGS ?= -mod=readonly -buildvcs=auto
 # Setup go-make version to use desired build and config scripts.
-GOMAKE_DEP ?= github.com/tkrop/go-make@v0.0.159
+GOMAKE_DEP ?= github.com/tkrop/go-make@v0.0.164
 # Request targets from go-make show-targets target.
 TARGETS := $(shell command -v $(GOBIN)/go-make >/dev/null || \
 	$(GO) install $(INSTALL_FLAGS) $(GOMAKE_DEP) >&2 && \

VERSION

@@ -1 +1 @@
-0.0.45
+0.0.46

go.mod

@@ -1,6 +1,6 @@
 module github.com/tkrop/go-testing
 
-go 1.25.4
+go 1.25.5
 
 require (
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc
@@ -10,13 +10,13 @@ require (
 	github.com/stretchr/testify v1.11.1
 	go.uber.org/mock v0.6.0
 	golang.org/x/text v0.30.0
-	golang.org/x/tools v0.38.0
+	golang.org/x/tools v0.40.0
 )
 
 require (
 	github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 // indirect
-	golang.org/x/mod v0.30.0 // indirect
-	golang.org/x/sync v0.18.0 // indirect
+	golang.org/x/mod v0.31.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -28,14 +28,14 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 go.uber.org/mock v0.6.0 h1:hyF9dfmbgIX5EfOdasqLsWD6xqpNZlXblLB/Dbnwv3Y=
 go.uber.org/mock v0.6.0/go.mod h1:KiVJ4BqZJaMj4svdfmHM0AUx4NJYO8ZNpPnZn1Z+BBU=
-golang.org/x/mod v0.30.0 h1:fDEXFVZ/fmCKProc/yAXXUijritrDzahmwwefnjoPFk=
-golang.org/x/mod v0.30.0/go.mod h1:lAsf5O2EvJeSFMiBxXDki7sCgAxEUcZHXoXMKT4GJKc=
-golang.org/x/sync v0.18.0 h1:kr88TuHDroi+UVf+0hZnirlk8o8T+4MrK6mr60WkH/I=
-golang.org/x/sync v0.18.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
+golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
+golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
 golang.org/x/text v0.30.0/go.mod h1:yDdHFIX9t+tORqspjENWgzaCVXgk0yYnYuSZ8UzzBVM=
-golang.org/x/tools v0.38.0 h1:Hx2Xv8hISq8Lm16jvBZ2VQf+RLmbd7wVUsALibYI/IQ=
-golang.org/x/tools v0.38.0/go.mod h1:yEsQ/d/YK8cjh0L6rZlY8tgtlKiBNTL14pGDJPJpYQs=
+golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
+golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

test/pattern.go

@@ -182,7 +182,7 @@ type DeepCopyParams struct {
 
 // typeToTestName converts a reflect.Type into a human readable test case name.
 // The name is derived from the base (non-pointer) type's CamelCase identifier
-// converted to a space separated lower-case string. For unnamed types the
+// converted to a hyphen-separated lower-case string. For unnamed types the
 // string representation of the type is used as a fallback.
 func typeToTestName(typ reflect.Type) string {
 	raw := typ.Name()
@@ -191,14 +191,20 @@ func typeToTestName(typ reflect.Type) string {
 	}
 	runes := []rune(raw)
 
+	last := byte('-')
 	var b strings.Builder
 	for i, r := range runes {
 		if i > 0 && unicode.IsUpper(r) && (unicode.IsLower(runes[i-1]) ||
-			(i+1 < len(runes) && unicode.IsLower(runes[i+1]))) {
-			b.WriteByte(' ')
+			(i+1 < len(runes) && unicode.IsLower(runes[i+1]))) &&
+			(unicode.IsLetter(runes[i-1]) || unicode.IsDigit(runes[i-1])) {
+			b.WriteByte('-')
 		}
 		b.WriteRune(unicode.ToLower(r))
+		if r == ' ' {
+			last = byte(' ')
+		}
 	}
+	b.WriteByte(last)
 	return b.String()
 }
 
@@ -226,10 +232,10 @@ func DeepCopyTestCases(
 		ptrType := reflect.PointerTo(base)
 		nilPtr := reflect.Zero(ptrType).Interface()
 
-		cases[name+" nil"] = DeepCopyParams{
+		cases[name+"nil"] = DeepCopyParams{
 			Value: nilPtr,
 		}
-		cases[name+" value"] = DeepCopyParams{
+		cases[name+"value"] = DeepCopyParams{
 			Value: random.Random(nilPtr),
 		}
 	}
@@ -273,8 +279,12 @@ func DeepCopy(t Test, p DeepCopyParams) {
 	}
 
 	// Then
-	if !reflect.ValueOf(value).IsNil() {
-		assert.NotSame(t, value, result)
+	rv := reflect.ValueOf(value)
+	if !rv.IsNil() {
+		// Only check NotSame for pointer types
+		if rv.Kind() == reflect.Ptr {
+			assert.NotSame(t, value, result)
+		}
 		assert.Equal(t, value, result)
 	} else {
 		assert.Nil(t, result)

test/pattern_test.go

@@ -518,30 +518,66 @@ func TestMainUnexpected(t *testing.T) {
 	test.Param(t, test.MainParams{}).RunSeq(test.Main(main))
 }
 
-type deepCopy struct {
+type (
+	noCopySlice   []int
+	deepCopySlice []int
+)
+
+func (d deepCopySlice) DeepCopy() deepCopySlice {
+	if d == nil {
+		return nil
+	}
+
+	copied := make(deepCopySlice, len(d))
+	copy(copied, d)
+
+	return copied
+}
+
+type (
+	noCopyMap   map[string]int
+	deepCopyMap map[string]int
+)
+
+func (d deepCopyMap) DeepCopy() deepCopyMap {
+	if d == nil {
+		return nil
+	}
+
+	copied := make(deepCopyMap)
+	for k, v := range d {
+		copied[k] = v
+	}
+
+	return copied
+}
+
+type noCopyStruct struct {
+	Value int
+}
+
+type deepCopyStruct struct {
 	Value int
 }
 
-func (d *deepCopy) DeepCopy() *deepCopy {
-	if d != nil {
-		return &deepCopy{Value: d.Value}
+func (d *deepCopyStruct) DeepCopy() *deepCopyStruct {
+	if d == nil {
+		return nil
 	}
-	return nil
+
+	return &deepCopyStruct{Value: d.Value}
 }
 
 type deepCopyObject struct {
 	Value int
 }
 
 func (d *deepCopyObject) DeepCopyObject() *deepCopyObject {
-	if d != nil {
-		return &deepCopyObject{Value: d.Value}
+	if d == nil {
+		return nil
 	}
-	return nil
-}
 
-type noCopyMethod struct {
-	Value int
+	return &deepCopyObject{Value: d.Value}
 }
 
 // DeepCopyCasesParams defines parameters for testing DeepCopyTestCases.
@@ -552,35 +588,71 @@ type DeepCopyCasesParams struct {
 
 var deepCopyTestCasesTestCases = map[string]DeepCopyCasesParams{
 	"struct types": {
-		args: []any{&deepCopy{}, &deepCopyObject{}, &noCopyMethod{}},
+		args: []any{
+			&noCopySlice{},
+			&deepCopySlice{},
+			&noCopyMap{},
+			&deepCopyMap{},
+			&noCopyStruct{},
+			&deepCopyStruct{},
+			&deepCopyObject{},
+		},
 		expect: map[string]test.DeepCopyParams{
-			"deep copy nil": {
-				Value: (*deepCopy)(nil),
+			"no-copy-slice-nil": {
+				Value: (*noCopySlice)(nil),
 			},
-			"deep copy value": {
-				Value: &deepCopy{Value: 6},
+			"no-copy-slice-value": {
+				Value: &noCopySlice{8, 9, 1},
 			},
-			"deep copy object nil": {
-				Value: (*deepCopyObject)(nil),
+			"deep-copy-slice-nil": {
+				Value: (*deepCopySlice)(nil),
 			},
-			"deep copy object value": {
-				Value: &deepCopyObject{Value: 8},
+			"deep-copy-slice-value": {
+				Value: &deepCopySlice{6, 8},
+			},
+			"no-copy-map-nil": {
+				Value: (*noCopyMap)(nil),
+			},
+			"no-copy-map-value": {
+				Value: &noCopyMap{
+					"6jif9":    5,
+					"g21qrot5": 10,
+					"hbl":      6,
+				},
+			},
+			"deep-copy-map-nil": {
+				Value: (*deepCopyMap)(nil),
+			},
+			"deep-copy-map-value": {
+				Value: &deepCopyMap{"5srwst": 3},
 			},
-			"no copy method nil": {
-				Value: (*noCopyMethod)(nil),
+			"no-copy-struct-nil": {
+				Value: (*noCopyStruct)(nil),
 			},
-			"no copy method value": {
-				Value: &noCopyMethod{Value: 9},
+			"no-copy-struct-value": {
+				Value: &noCopyStruct{Value: 8},
+			},
+			"deep-copy-struct-nil": {
+				Value: (*deepCopyStruct)(nil),
+			},
+			"deep-copy-struct-value": {
+				Value: &deepCopyStruct{Value: 6},
+			},
+			"deep-copy-object-nil": {
+				Value: (*deepCopyObject)(nil),
+			},
+			"deep-copy-object-value": {
+				Value: &deepCopyObject{Value: 8},
 			},
 		},
 	},
 	"anonymous struct type": {
 		args: []any{&struct{ Value int }{}},
 		expect: map[string]test.DeepCopyParams{
-			"struct {  value int } nil": {
+			"struct { value int } nil": {
 				Value: (*struct{ Value int })(nil),
 			},
-			"struct {  value int } value": {
+			"struct { value int } value": {
 				Value: &struct{ Value int }{Value: 6},
 			},
 		},
@@ -604,47 +676,67 @@ type DeepCopyParams struct {
 }
 
 var deepCopyTestCases = map[string]DeepCopyParams{
-	"deep copy nil": {
+	"deep-copy-nil": {
 		DeepCopyParams: test.DeepCopyParams{
-			Value: (*deepCopy)(nil),
+			Value: (*deepCopyStruct)(nil),
 		},
 	},
-	"deep-copy value": {
+	"deep-copy-value": {
 		DeepCopyParams: test.DeepCopyParams{
-			Value: &deepCopy{Value: 2},
+			Value: &deepCopyStruct{Value: 2},
 		},
 	},
-	"deep copy object nil": {
+	"deep-copy-object-nil": {
 		DeepCopyParams: test.DeepCopyParams{
 			Value: (*deepCopyObject)(nil),
 		},
 	},
-	"deep copy object value": {
+	"deep-copy-object-value": {
 		DeepCopyParams: test.DeepCopyParams{
 			Value: &deepCopyObject{Value: 4},
 		},
 	},
-	"no copy method nil": {
+	"deep-copy-slice-nil": {
+		DeepCopyParams: test.DeepCopyParams{
+			Value: deepCopySlice(nil),
+		},
+	},
+	"deep-copy-slice-value": {
+		DeepCopyParams: test.DeepCopyParams{
+			Value: deepCopySlice{1, 2, 3},
+		},
+	},
+	"deep-copy-map-nil": {
+		DeepCopyParams: test.DeepCopyParams{
+			Value: deepCopyMap(nil),
+		},
+	},
+	"deep-copy-map-value": {
+		DeepCopyParams: test.DeepCopyParams{
+			Value: deepCopyMap{"key": 42},
+		},
+	},
+	"no-copy-method-nil": {
 		DeepCopyParams: test.DeepCopyParams{
 			Value: nil,
 		},
 		setup: test.Fatalf("no deep copy method [%T]", nil),
 	},
-	"no copy method value": {
+	"no-copy-method-value": {
 		DeepCopyParams: test.DeepCopyParams{
-			Value: &noCopyMethod{Value: 6},
+			Value: &noCopyStruct{Value: 6},
 		},
 		setup: test.Fatalf("no deep copy method [%T]",
-			&noCopyMethod{Value: 6}),
+			&noCopyStruct{Value: 6}),
 	},
-	"anonymous struct nil": {
+	"anonymous-struct-nil": {
 		DeepCopyParams: test.DeepCopyParams{
 			Value: (*struct{ Value int })(nil),
 		},
 		setup: test.Fatalf("no deep copy method [%T]",
 			(*struct{ Value int })(nil)),
 	},
-	"anonymous struct value": {
+	"anonymous-struct-value": {
 		DeepCopyParams: test.DeepCopyParams{
 			Value: &struct{ Value int }{Value: 8},
 		},