github.com/cncf/xds/go v0.0.0-20250501225837-2ac532fd4443: v3.ContextParams

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/cncf/xds/go/xds/core/v3.ContextParams in pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443
Demonstrate these symbols/APIs:
  - github.com/cncf/xds/go/xds/core/v3.ContextParams

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:8616995ca03160a256845105766838746d28a0862601a60e7c117bcf553cc007","contract":["ContextParams initializes with key-value pairs in Params map","ContextParams getters safely return values and handle nil receivers without panic","ContextParams validation succeeds for valid instances including empty and populated params","ContextParams serializes to and deserializes from binary Protobuf format satisfying proto.Equal","proto.Clone produces an isolated deep copy of ContextParams where mutating fields does not affect the original"],"goal":"verify github.com/cncf/xds/go/xds/core/v3.ContextParams in pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443","kind":"HOW","packages":["pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443"],"schemaVersion":1,"symbols":["github.com/cncf/xds/go/xds/core/v3.ContextParams"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443"],"schemaVersion":1,"subject":"pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443","symbols":["github.com/cncf/xds/go/xds/core/v3.ContextParams"],"verifierAdapter":"golang@1"}

module example.com/contextparams

go 1.23.0

require (
	github.com/cncf/xds/go v0.0.0-20250501225837-2ac532fd4443
	google.golang.org/protobuf v1.33.0
)

require github.com/envoyproxy/protoc-gen-validate v1.0.4 // indirect

github.com/cncf/xds/go v0.0.0-20250501225837-2ac532fd4443 h1:aQ3y1lwWyqYPiWZThqv1aFbZMiM9vblcSArJRf2Irls=
github.com/cncf/xds/go v0.0.0-20250501225837-2ac532fd4443/go.mod h1:W+zGtBO5Y1IgJhy4+A9GOqVhqLpfZi+vwmdNXUehLA8=
github.com/envoyproxy/protoc-gen-validate v1.0.4 h1:gVPz/FMfvh57HdSJQyvBtF00j8JU4zdyUgIUNhlgg0A=
github.com/envoyproxy/protoc-gen-validate v1.0.4/go.mod h1:qys6tmnRsYrQqIhm2bvKZH4Blx/1gTIZ2UKVY1M+Yew=
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/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=

{
  "schemaVersion": 1,
  "goal": "verify github.com/cncf/xds/go/xds/core/v3.ContextParams in pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/cncf/xds/go@v0.0.0-20250501225837-2ac532fd4443"
  ],
  "symbols": [
    "github.com/cncf/xds/go/xds/core/v3.ContextParams"
  ]
}

package main

import (
	"fmt"
	"os"

	corev3 "github.com/cncf/xds/go/xds/core/v3"
	"google.golang.org/protobuf/proto"
)

func assert(condition bool, message string) {
	if !condition {
		fmt.Fprintf(os.Stderr, "assertion failed: %s\n", message)
		os.Exit(1)
	}
}

func main() {
	// Assertion 1: ContextParams initializes with key-value pairs in Params map
	{
		params := &corev3.ContextParams{
			Params: map[string]string{
				"env":     "prod",
				"version": "v1.0",
				"zone":    "us-central1-a",
			},
		}
		assert(params.GetParams() != nil, "expected non-nil Params map")
		assert(len(params.GetParams()) == 3, "expected 3 params entries")
		assert(params.GetParams()["env"] == "prod", "expected env=prod")
		assert(params.GetParams()["version"] == "v1.0", "expected version=v1.0")
		assert(params.GetParams()["zone"] == "us-central1-a", "expected zone=us-central1-a")
	}

	// Assertion 2: ContextParams getters safely return values and handle nil receivers without panic
	{
		var nilParams *corev3.ContextParams
		assert(nilParams.GetParams() == nil, "nil ContextParams GetParams must return nil")
		assert(nilParams.Validate() == nil, "nil ContextParams Validate must return nil")
		assert(nilParams.ValidateAll() == nil, "nil ContextParams ValidateAll must return nil")

		emptyParams := &corev3.ContextParams{}
		assert(emptyParams.GetParams() == nil, "empty ContextParams GetParams must return nil")
		assert(len(emptyParams.GetParams()) == 0, "empty ContextParams GetParams length must be 0")
	}

	// Assertion 3: ContextParams validation succeeds for valid instances including empty and populated params
	{
		emptyParams := &corev3.ContextParams{}
		assert(emptyParams.Validate() == nil, "expected empty ContextParams Validate() to return nil")
		assert(emptyParams.ValidateAll() == nil, "expected empty ContextParams ValidateAll() to return nil")

		populatedParams := &corev3.ContextParams{
			Params: map[string]string{
				"service": "backend",
				"cluster": "cluster-1",
			},
		}
		assert(populatedParams.Validate() == nil, "expected populated ContextParams Validate() to return nil")
		assert(populatedParams.ValidateAll() == nil, "expected populated ContextParams ValidateAll() to return nil")
	}

	// Assertion 4: ContextParams serializes to and deserializes from binary Protobuf format satisfying proto.Equal
	{
		orig := &corev3.ContextParams{
			Params: map[string]string{
				"app":    "web",
				"region": "europe-west1",
			},
		}
		wire, err := proto.Marshal(orig)
		assert(err == nil, "proto.Marshal failed")
		assert(len(wire) > 0, "marshaled wire length is 0")

		unmarshaled := &corev3.ContextParams{}
		err = proto.Unmarshal(wire, unmarshaled)
		assert(err == nil, "proto.Unmarshal failed")
		assert(proto.Equal(orig, unmarshaled), "proto.Equal returned false after unmarshal")
		assert(unmarshaled.GetParams()["app"] == "web", "unmarshaled param app mismatch")
		assert(unmarshaled.GetParams()["region"] == "europe-west1", "unmarshaled param region mismatch")
	}

	// Assertion 5: proto.Clone produces an isolated deep copy of ContextParams where mutating fields does not affect the original
	{
		orig := &corev3.ContextParams{
			Params: map[string]string{
				"stage": "staging",
			},
		}
		cloned := proto.Clone(orig).(*corev3.ContextParams)
		assert(proto.Equal(orig, cloned), "cloned ContextParams must equal original")

		cloned.Params["stage"] = "production"
		cloned.Params["new_key"] = "new_val"

		assert(orig.GetParams()["stage"] == "staging", "original Params map was mutated")
		assert(orig.GetParams()["new_key"] == "", "original Params map received unexpected key")
	}

	fmt.Println("PASS: all github.com/cncf/xds/go/xds/core/v3.ContextParams contract assertions verified")
}