Purge CEL Conformance gRPC server (#401)

* Remove conformance gRPC server implementation
* Update bazel build to skip tests since there are none

cloudbuild.yaml

@@ -1,8 +1,8 @@
 steps:
 - name: 'gcr.io/cloud-builders/bazel:6.4.0'
   entrypoint: bazel
-  args: ['test', '--test_output=errors', '...']
-  id: bazel-test
+  args: ['build', '...']
+  id: bazel-build
   waitFor: ['-']
 timeout: 15m
 options:

go.mod

@@ -5,15 +5,9 @@ go 1.21.1
 toolchain go1.23.0
 
 require (
-	github.com/bazelbuild/rules_go v0.49.0
 	google.golang.org/genproto/googleapis/api v0.0.0-20240826202546-f6391c0de4c7
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240826202546-f6391c0de4c7
-	google.golang.org/grpc v1.65.0
 	google.golang.org/protobuf v1.34.2
 )
 
-require (
-	golang.org/x/net v0.26.0 // indirect
-	golang.org/x/sys v0.21.0 // indirect
-	golang.org/x/text v0.16.0 // indirect
-)
+require github.com/google/go-cmp v0.6.0 // indirect

go.sum

@@ -1,18 +1,8 @@
-github.com/bazelbuild/rules_go v0.49.0 h1:5vCbuvy8Q11g41lseGJDc5vxhDjJtfxr6nM/IC4VmqM=
-github.com/bazelbuild/rules_go v0.49.0/go.mod h1:Dhcz716Kqg1RHNWos+N6MlXNkjNP2EwZQ0LukRKJfMs=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
-golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
-golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
-golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
-golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
 google.golang.org/genproto/googleapis/api v0.0.0-20240826202546-f6391c0de4c7 h1:YcyjlL1PRr2Q17/I0dPk2JmYS5CDXfcdb2Z3YRioEbw=
 google.golang.org/genproto/googleapis/api v0.0.0-20240826202546-f6391c0de4c7/go.mod h1:OCdP9MfskevB/rbYvHTsXTtKC+3bHWajPdoKgjcYkfo=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20240826202546-f6391c0de4c7 h1:2035KHhUv+EpyB+hWgJnaWKJOdX1E95w2S8Rr4uWKTs=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20240826202546-f6391c0de4c7/go.mod h1:UqMtugtsSgubUsoxbuAoiCXvqvErP7Gf0so0mK9tHxU=
-google.golang.org/grpc v1.65.0 h1:bs/cUb4lp1G5iImFFd3u5ixQzweKizoZJAwBNLR42lc=
-google.golang.org/grpc v1.65.0/go.mod h1:WgYC2ypjlB0EiQi6wdKixMqukr6lBc0Vo+oOgjrM5ZQ=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=

tests/BUILD.bazel

@@ -4,8 +4,4 @@ package(
 
 licenses(["notice"])  # Apache 2.0
 
-exports_files([
-    "LICENSE",
-    "conftest.sh",
-    "conftest-nofail.sh",
-])
+exports_files(["LICENSE"])

tests/README.md

@@ -1,58 +1,18 @@
 # CEL Conformance Tests
 
 The CEL conformance test suites provide a complementary specification
-of the CEL language in the form of executable software.  All CEL
+of the CEL language in the form of executable software. All CEL
 implementations which pass the conformance tests should give valid CEL
 expressions the same meaning.
 
-A language-independent gRPC protocol allows the tests to run against CEL
-components in any language which implement a server for the protocol.
+As much as possible, the tests are driven by data files. Implementations
+are expected to read the `tests/simple/testdata` files as inputs to the
+parse, check, and evaluation behaviors of a given implementation. Reference
+implementations may be found in the following locations:
 
-As much as possible, the tests are driven by data files.  Implementations
-which do not provide a ConformanceService server are welcome to write
-their own drivers which read the same `testdata` files.
-
-## Test Suites
-
-We currently have the following test suites:
-- *[simple](simple)* The _simple_ tests check the end-to-end
-  parse-(check)-eval pipeline for fully-specified expressions,
-  inputs, and output without parse or check failures.
-- *[envcheck](envcheck)* The _envcheck_ suite confirms that the checker and
-  runtime support a set of functions and overloads (though we don't check
-  the behavior of these functions in this suite).
-- Test suites more suitable for other kinds of validation may be introduced
-  later.
-
-## Integrating with the Tests
-
-Implementations should write a gRPC server for the
-[`ConformanceService`
-API](https://github.com/googleapis/googleapis/blob/master/google/api/expr/v1alpha1/conformance_service.proto)
-See [the cel-go server](https://github.com/google/cel-go/tree/master/server)
-as an example.
-
-The server should be available as an executable file.  When invoked without
-without arguments, the server should listen on an arbitrary available TCP
-port on the local loopback address (`127.0.0.1` or `::1`), then write its
-address on `stdout` in the format
-
-> `Listening on `_address_`:`_port_
-
-See the [celrpc
-library](https://github.com/google/cel-spec/tree/master/tools/celrpc) for an
-example of implementing this protocol.
-
-An implementation with only a subset of the execution phases (particularly
-runtime-only implementations without a parser or checker) is free to
-support only the corresponding API methods.  The test suite driver can be
-instructed to use a different implementation for the unsupported methods.
-
-Each conformance test suite will contain specific integration instructions.
-
-Implementations which use the [bazel](https://bazel.build) build system
-should copy the relevant entries out of the `WORKSPACE` file at the root
-of this repository.
+* (cel-go conformance)[https://github.com/google/cel-go/tree/master/conformance]
+* (cel-cpp conformance)[https://github.com/google/cel-cpp/tree/master/conformance]
+* (cel-java conformance)[https://github.com/google/cel-java/tree/main/conformance/src/test/java/dev/cel/conformance]
 
 Each CEL implementation should also have its own unit tests and benchmarks
 for testing subcomponents, its API, and other implementation-dependent