panic: runtime error: invalid memory address or nil pointer dereference

[liuzehao]

I follow your tutorial completely, but in the [gRPC #10.1] Implement unary gRPC API - Golang,I encountered the following error：

Running tool: /usr/local/opt/go/libexec/bin/go test -timeout 30s -run ^TestServerCreateLaptop$ gitlab.com/techschool/pcbook/service

--- FAIL: TestServerCreateLaptop (0.00s)
--- FAIL: TestServerCreateLaptop/success_with_id (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x14bfe44]

goroutine 35 [running]:
testing.tRunner.func1.1(0x15663a0, 0x1a9bd50)
/usr/local/opt/go/libexec/src/testing/testing.go:940 +0x2f5
testing.tRunner.func1(0xc0000ba000)
/usr/local/opt/go/libexec/src/testing/testing.go:943 +0x3f9
panic(0x15663a0, 0x1a9bd50)
/usr/local/opt/go/libexec/src/runtime/panic.go:969 +0x166
gitlab.com/techschool/pcbook/service.(*LaptopServer).CreateLaptop(0xc000094f30, 0x16d9a20, 0xc00011e008, 0xc000094f40, 0x160134df, 0xc000046800, 0xc000094f18)
/Users/mac/Documents/golang/pcbook/service/laptop_server.go:47 +0x124
gitlab.com/techschool/pcbook/service_test.TestServerCreateLaptop.func1(0xc0000ba000)
/Users/mac/Documents/golang/pcbook/service/laptop_server_test.go:72 +0xd0
testing.tRunner(0xc0000ba000, 0xc0000a4ac0)
/usr/local/opt/go/libexec/src/testing/testing.go:991 +0xdc
created by testing.(*T).Run
/usr/local/opt/go/libexec/src/testing/testing.go:1042 +0x357
FAIL gitlab.com/techschool/pcbook/service 0.892s
FAIL
I don't know how to solve it. Can you help me？

[yuvan11]

@liuzehao I also encountered the same issue while following [gRPC #10.1] Implement unary gRPC API - Golang,

I solved it by replacing few lines of code,

changing to

Reference files,
laptop_server.go : https://gist.github.com/yuvan11/ab0f4aea31149f0617847c84796c5e96
laptop_server_test.go : https://gist.github.com/yuvan11/5881101dd93810983f9ac1243f8cbd89

After doing that, test file got passed.