Table Driven Tests - best practice

TableDrivenTests -github.com/golang/go/wiki/TableDrivenTests

1. VSCode Golang plugin Go: Generate Unit Tests for Function
2. Goland plugin

hello.go

exmaple

func hello(ctx context.Context, name string) (string, error) {
	return fmt.Sprintf("hello %s", name), nil
}

hello_test.go

generate by VSCode

func Test_hello(t *testing.T) {
	type args struct {
		ctx  context.Context
		name string
	}
	tests := []struct {
		name    string
		args    args
		want    string
		wantErr bool
	}{
		// TODO: Add test cases.
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := hello(tt.args.ctx, tt.args.name)
			if (err != nil) != tt.wantErr {
				t.Errorf("hello() error = %v, wantErr %v", err, tt.wantErr)
				return
			}
			if got != tt.want {
				t.Errorf("hello() = %v, want %v", got, tt.want)
			}
		})
	}
}

hello_test.go

Manually update version1

func Test_hello(t *testing.T) {
	// one of the external client calling
	var auditLogMock *mocks.ILogClient

	type args struct {
		ctx  context.Context
		name string
	}
	tests := []struct {
		name        string
		args        args
		want        string
		wantErr     bool
		origin      []interface{}
		setupMocks  func()
		verifyMocks func()
	}{
		{
			name: "happy path",
			args: args{
				ctx:  context.Background(),
				name: "wdxxl",
			},
			want:    "hello wdxxl",
			wantErr: false,
			origin:  []interface{}{external.AuditLogClient},
			setupMocks: func() {
				// mock interface
				auditLogMock = &mocks.ILogClient{}
				auditLogMock.On("AsyncSendAuditLog", mock.Anything, mock.Anything)
				external.AuditLogClient = auditLogMock
			},
			verifyMocks: func() {
				// verify the interface been called or not
				auditLogMock.AssertNumberOfCalls(t, "AsyncSendAuditLog", 1)
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// golang unit test setup & restore individual
			defer testtools.Restore(testtools.Pairs(tt.origin...)...)
			tt.setupMocks()
			defer tt.verifyMocks()

			got, err := hello(tt.args.ctx, tt.args.name)
			if (err != nil) != tt.wantErr {
				t.Errorf("hello() error = %v, wantErr %v", err, tt.wantErr)
				return
			}
			if got != tt.want {
				t.Errorf("hello() = %v, want %v", got, tt.want)
			}
		})
	}
}

hello_test.go

Manually update version2

func Test_hello(t *testing.T) {
	// one of the external client calling
	var auditLogMock *mocks.ILogClient

	type args struct {
		ctx  context.Context
		name string
	}
	tests := []struct {
		name        string
		args        args
		want        string
		wantErr     bool
		origin      []interface{}
		setupMocks  []func()
		verifyMocks func()
	}{
		{
			name: "happy path",
			args: args{
				ctx:  context.Background(),
				name: "wdxxl",
			},
			want:    "hello wdxxl",
			wantErr: false,
			origin:  []interface{}{external.AuditLogClient},
			setupMocks: []func() {
				func ()  { // move out as a common Function
					// mock interface
					auditLogMock = &mocks.ILogClient{}
					auditLogMock.On("AsyncSendAuditLog", mock.Anything, mock.Anything)
					external.AuditLogClient = auditLogMock
				},
			},
			verifyMocks: func() {
				// verify the interface been called or not
				auditLogMock.AssertNumberOfCalls(t, "AsyncSendAuditLog", 1)
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// golang unit test setup & restore individual
			defer testtools.Restore(testtools.Pairs(tt.origin...)...)
			for _, mocks := range tt.setupMocks() {
				mocks()
			}
			defer tt.verifyMocks()

			got, err := hello(tt.args.ctx, tt.args.name)
			if (err != nil) != tt.wantErr {
				t.Errorf("hello() error = %v, wantErr %v", err, tt.wantErr)
				return
			}
			if got != tt.want {
				t.Errorf("hello() = %v, want %v", got, tt.want)
			}
		})
	}
}