Autopkgtest failure attempting to test deprecated/removed api

[Bryce Harrington]

golang-github-grpc-ecosystem-grpc-gateway started failing its autopkgtests when tested with golang-goprotobuf/1.4.2-0ubuntu1.

See https://autopkgtest.ubuntu.com/packages/g/golang-github-grpc-ecosystem-grpc-gateway/groovy/amd64

The specific failing test case output is:

--- FAIL: TestParseRequest (0.00s)
    --- FAIL: TestParseRequest/Empty_input_should_produce_empty_output (0.00s)
    --- PASS: TestParseRequest/Invalid_reader_should_produce_error (0.00s)
    --- PASS: TestParseRequest/Invalid_proto_message_should_produce_error (0.00s)
FAIL
FAIL github.com/grpc-ecosystem/grpc-gateway/codegenerator 0.034s
? github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway [no test files]
WARNING: Package "github.com/golang/protobuf/protoc-gen-go/generator" is deprecated.
        A future release of golang/protobuf will delete this package,
        which has long been excluded from the compatibility promise.
--- PASS: TestAnnotateContext_SupportsCustomAnnotators (0.00s)
=== RUN TestDefaultHTTPError
--- FAIL: TestDefaultHTTPError (0.00s)
panic: mismatching field: got github_com.grpc_ecosystem.grpc_gateway.runtime.errorBody.error, want github_com.grpc_ecosystem.grpc_gateway.runtime.errorBody.message [recovered]
        panic: mismatching field: got github_com.grpc_ecosystem.grpc_gateway.runtime.errorBody.error, want github_com.grpc_ecosystem.grpc_gateway.runtime.errorBody.message
...
FAIL github.com/grpc-ecosystem/grpc-gateway/runtime 0.032s
? github.com/grpc-ecosystem/grpc-gateway/runtime/internal [no test files]

In decyphering what all that means, it's essentially just failing this one test case:

    import (
        ...
        "github.com/golang/protobuf/proto"
        plugin "github.com/golang/protobuf/protoc-gen-go/plugin"
        "github.com/grpc-ecosystem/grpc-gateway/codegenerator"
    )

    var parseReqTests = []struct {
            name string
            in io.Reader
            out *plugin.CodeGeneratorRequest
            err error
    }{
            {
                    "Empty input should produce empty output",
                    mustGetReader(&plugin.CodeGeneratorRequest{}),
                    &plugin.CodeGeneratorRequest{},
                    nil,
            },

Which is just a "" == "" sanity check test case.

The warning up above is triggered by the init of protoc-gen-go/generator by this test case, and it suggests that protoc-gen-go/generator's API does not have a stability guarantee and is deprecated for removal. My guess is that our change from golang-goprotobuf 1.3.x (currently in groovy) to golang-goprotobuf 1.4.x (currently in groovy-proposed) involves (at least) a behavioral change in this particular API that is triggering this test failure.

Our golang-github-grpc-ecosystem-grpc-gateway 1.6.4 is far behind upstream. They dropped their use of protoc-gen-go/generator with their v1.14.5 release (See https://github.com/grpc-ecosystem/grpc-gateway/issues/1209, https://github.com/grpc-ecosystem/grpc-gateway/pull/1260, and https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.14.5) although I notice they did not update this particular test case.

My guess is we can simply disable the test for now, so as to at least unblock golang-goprotobuf.

[Bryce Harrington (bryce)]

The "panic: mismatching field" error for TestDefaultHTTPError appears to be a second, unrelated error, raised with Debian:

https://<email address hidden>/msg08294.html

like the other issue, it is likely resolved with a newer version of golang-github-grpc-ecosystem-grpc-gateway

[Bryce Harrington (bryce)]

This patch disables the test case broken by golang-goprotobuf 1.4's API change. Testing it locally shows it resolves the test failure.

[Bryce Harrington (bryce)]

The second error, regarding the panic about message/error mixup, is this upstream issue:

https://github.com/grpc-ecosystem/grpc-gateway/pull/1016

The patch didn't apply cleanly to the 1.6.4 tree but it's trivial to backport manually.

Unfortunately, while it did eliminate the panic, it unfortunately then unblocked a bunch more test cases to be able to run, several of which had their own failures:

    marshal_jsonpb_test.go:114: case 4: got = single_nested:<> uuid:"6EC2446F-7E89-4127-B3E6-5C05E6BECBA7" nested:<name:"foo" amount:12345 > uint64_value:18446744073709551615 enum_value:ONE oneof_string:"bar" map_value:<key:"a" value:ONE > map_value:<key:"b" value:ZERO > timestamp_value:<> ; want single_nested:<> uuid:"6EC2446F-7E89-4127-B3E6-5C05E6BECBA7" nested:<name:"foo" amount:12345 > uint64_value:18446744073709551615 enum_value:ONE oneof_string:"bar" map_value:<key:"a" value:ONE > map_value:<key:"b" value:ZERO > timestamp_value:<> ; spec={false false true 0x97b170}
--- FAIL: TestJSONPbMarshal (0.00s)

    marshal_jsonpb_test.go:232: dest = &wrapperspb.UInt64Value{state:impl.MessageState{NoUnkeyedLiterals:pragma.NoUnkeyedLiterals{}, DoNotCompare:pragma.DoNotCompare{}, DoNotCopy:pragma.DoNotCopy{}, atomicMessageInfo:(*impl.MessageInfo)(0xc0001a03a8)}, sizeCache:0, unknownFields:[]uint8(nil), Value:0x7b}; want &wrapperspb.UInt64Value{state:impl.MessageState{NoUnkeyedLiterals:pragma.NoUnkeyedLiterals{}, DoNotCompare:pragma.DoNotCompare{}, DoNotCopy:pragma.DoNotCopy{}, atomicMessageInfo:(*impl.MessageInfo)(nil)}, sizeCache:0, unknownFields:[]uint8(nil), Value:0x7b}; input = "123"
--- FAIL: TestJSONPbUnmarshalFields (0.00s)

=== RUN TestPopulateParameters
--- FAIL: TestPopulateParameters (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=0xb0 pc=0x7bdda7]

I'm guessing there are also upstream fixes for those, but am becoming convinced that Balint is right and efforts would be better targeted to merge a newer version of the package.