✨ add first implementation

_example/repo.go

@@ -0,0 +1,28 @@
+package _example
+
+import (
+	"context"
+	"time"
+)
+
+type User struct {
+	Name, Address string
+	CreateAt      time.Time
+}
+
+type UserRepo interface {
+	Save(context.Context, *User) error
+}
+
+type UserUsecase struct {
+	Repo UserRepo
+}
+
+func (uu *UserUsecase) Register(ctx context.Context, name, address string) error {
+	u := &User{
+		Name:     name,
+		Address:  address,
+		CreateAt: time.Now(),
+	}
+	return uu.Repo.Save(ctx, u)
+}

_example/repo_test.go

@@ -0,0 +1,34 @@
+package _example_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/budougumi0617/cmpmock"
+	"github.com/budougumi0617/cmpmock/_example"
+	"github.com/budougumi0617/cmpmock/_example/mock_example"
+	"github.com/golang/mock/gomock"
+)
+
+func TestUserUsecase_Save(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	t.Cleanup(ctrl.Finish)
+	ctx := context.Background()
+	name := "John Due"
+	address := "Tokyo"
+	wantUser := &_example.User{
+		Name:     name,
+		Address:  address,
+		CreateAt: time.Now(),
+	}
+
+	mrepo := mock_example.NewMockUserRepo(ctrl)
+	mrepo.EXPECT().Save(ctx, cmpmock.DiffEq(wantUser)).Return(nil)
+
+	sut := _example.UserUsecase{Repo: mrepo}
+
+	if err := sut.Register(ctx, name, address); err != nil {
+		t.Fatal(err)
+	}
+}

diffmatcher.go

@@ -0,0 +1,35 @@
+package cmpmock
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/golang/mock/gomock"
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+)
+
+func DiffEq(v interface{}, opts ...cmp.Option) gomock.Matcher {
+	var lopts cmp.Options
+	if len(opts) == 0 {
+		lopts = append(lopts, cmpopts.EquateApproxTime(1*time.Second))
+	} else {
+		lopts = append(lopts, opts...)
+	}
+	return &diffMatcher{want: v, opts: lopts}
+}
+
+type diffMatcher struct {
+	want interface{}
+	diff string
+	opts cmp.Options
+}
+
+func (d *diffMatcher) Matches(x interface{}) bool {
+	d.diff = cmp.Diff(x, d.want, d.opts...)
+	return len(d.diff) == 0
+}
+
+func (d *diffMatcher) String() string {
+	return fmt.Sprintf("diff(-got +want) is %s", d.diff)
+}

diffmatcher_test.go

@@ -0,0 +1,50 @@
+package cmpmock
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func Test_DiffEq(t *testing.T) {
+	type Foo struct{ CreateAt time.Time }
+	t1 := time.Now()
+	t2 := t1.Add(100 * time.Millisecond)
+	defaultString := "diff(-got +want) is %s"
+	type args struct {
+		want interface{}
+		opts cmp.Options
+	}
+	tests := []struct {
+		name      string
+		args      args
+		x         Foo
+		wantMatch bool
+		wantDiff  string
+	}{
+		{
+			name: "diff less than a second with default option",
+			args: args{
+				want: Foo{CreateAt: t1},
+				opts: nil,
+			},
+			x:         Foo{CreateAt: t2},
+			wantMatch: true,
+			wantDiff:  "",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sut := DiffEq(tt.args.want, tt.args.opts...)
+			x := Foo{CreateAt: t2}
+			if got := sut.Matches(x); got != tt.wantMatch {
+				t.Errorf("Matches() = %v, want %v", got, tt.wantMatch)
+			}
+			if got := sut.String(); got != fmt.Sprintf(defaultString, tt.wantDiff) {
+				t.Errorf("String() = %q, want %q", got, tt.wantDiff)
+			}
+		})
+	}
+}

go.mod

@@ -1,3 +1,8 @@
 module github.com/budougumi0617/cmpmock
 
 go 1.16
+
+require (
+	github.com/golang/mock v1.5.0
+	github.com/google/go-cmp v0.5.5
+)

go.sum

@@ -0,0 +1,18 @@
+github.com/golang/mock v1.5.0 h1:jlYHihg//f7RRwuPfptm04yp4s7O6Kw8EZiVYIGcH0g=
+github.com/golang/mock v1.5.0/go.mod h1:CWnOUgYIOo4TcNZ0wHX3YZCqsaM1I1Jvs6v3mP3KVu8=
+github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=