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

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.ResourceLocator_Directive 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.ResourceLocator_Directive

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:sha256:40c578cba642105c1eb05738f9d52dd112f9f42cb4168e13acbbf8984236a77e","contract":["ResourceLocator_Directive initializes with Entry variant and getters safely return values","ResourceLocator_Directive initializes with Alt variant pointing to fallback ResourceLocator","ResourceLocator_Directive getters handle nil receivers, unpopulated instances, and mismatched oneof variants without panic","ResourceLocator_Directive validation succeeds for valid Entry matching pattern and valid Alt locator","ResourceLocator_Directive validation fails when directive oneof is unset, Entry format is invalid, or Alt locator fails validation","ResourceLocator_Directive serializes to and deserializes from binary Protobuf wire format satisfying proto.Equal","proto.Clone produces an isolated deep copy of ResourceLocator_Directive where mutating nested fields does not affect the original"],"goal":"verify github.com/cncf/xds/go/xds/core/v3.ResourceLocator_Directive 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.ResourceLocator_Directive"]},"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.ResourceLocator_Directive"],"verifierAdapter":"golang@1"}

module example.com/resourcelocatordirective

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.ResourceLocator_Directive 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.ResourceLocator_Directive"
  ]
}

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: ResourceLocator_Directive initializes with Entry variant and getters safely return values
	{
		entryDirective := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Entry{
				Entry: "primary-cluster",
			},
		}
		assert(entryDirective.GetEntry() == "primary-cluster", "expected entry value 'primary-cluster'")
		assert(entryDirective.GetAlt() == nil, "expected nil Alt on Entry directive")
		assert(entryDirective.GetDirective() != nil, "expected non-nil directive")

		switch d := entryDirective.GetDirective().(type) {
		case *corev3.ResourceLocator_Directive_Entry:
			assert(d.Entry == "primary-cluster", "expected entry field match in type switch")
		default:
			assert(false, "expected *corev3.ResourceLocator_Directive_Entry type")
		}
	}

	// Assertion 2: ResourceLocator_Directive initializes with Alt variant pointing to fallback ResourceLocator
	{
		altLocator := &corev3.ResourceLocator{
			Scheme:       corev3.ResourceLocator_XDSTP,
			ResourceType: "envoy.config.cluster.v3.Cluster",
			Id:           "fallback-cluster",
			Authority:    "example.com",
		}
		altDirective := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Alt{
				Alt: altLocator,
			},
		}
		assert(altDirective.GetAlt() != nil, "expected non-nil Alt locator")
		assert(altDirective.GetAlt().GetId() == "fallback-cluster", "expected Alt id 'fallback-cluster'")
		assert(altDirective.GetAlt().GetScheme() == corev3.ResourceLocator_XDSTP, "expected Alt scheme XDSTP")
		assert(altDirective.GetEntry() == "", "expected empty Entry string on Alt directive")

		switch d := altDirective.GetDirective().(type) {
		case *corev3.ResourceLocator_Directive_Alt:
			assert(d.Alt.GetResourceType() == "envoy.config.cluster.v3.Cluster", "expected Alt resource type match")
		default:
			assert(false, "expected *corev3.ResourceLocator_Directive_Alt type")
		}
	}

	// Assertion 3: ResourceLocator_Directive getters handle nil receivers, unpopulated instances, and mismatched oneof variants without panic
	{
		var nilDirective *corev3.ResourceLocator_Directive
		assert(nilDirective.GetDirective() == nil, "nil directive GetDirective must return nil")
		assert(nilDirective.GetAlt() == nil, "nil directive GetAlt must return nil")
		assert(nilDirective.GetEntry() == "", "nil directive GetEntry must return empty string")
		assert(nilDirective.Validate() == nil, "nil directive Validate must return nil")
		assert(nilDirective.ValidateAll() == nil, "nil directive ValidateAll must return nil")

		emptyDirective := &corev3.ResourceLocator_Directive{}
		assert(emptyDirective.GetDirective() == nil, "empty directive GetDirective must return nil")
		assert(emptyDirective.GetAlt() == nil, "empty directive GetAlt must return nil")
		assert(emptyDirective.GetEntry() == "", "empty directive GetEntry must return empty string")
	}

	// Assertion 4: ResourceLocator_Directive validation succeeds for valid Entry matching pattern and valid Alt locator
	{
		validEntry := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Entry{
				Entry: "valid_entry-name.123/~path",
			},
		}
		assert(validEntry.Validate() == nil, "expected valid Entry Validate() to return nil")
		assert(validEntry.ValidateAll() == nil, "expected valid Entry ValidateAll() to return nil")

		validAlt := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Alt{
				Alt: &corev3.ResourceLocator{
					Scheme:       corev3.ResourceLocator_XDSTP,
					ResourceType: "envoy.config.listener.v3.Listener",
				},
			},
		}
		assert(validAlt.Validate() == nil, "expected valid Alt Validate() to return nil")
		assert(validAlt.ValidateAll() == nil, "expected valid Alt ValidateAll() to return nil")
	}

	// Assertion 5: ResourceLocator_Directive validation fails when directive oneof is unset, Entry format is invalid, or Alt locator fails validation
	{
		unsetDirective := &corev3.ResourceLocator_Directive{}
		assert(unsetDirective.Validate() != nil, "expected Validate() error for unset directive")
		assert(unsetDirective.ValidateAll() != nil, "expected ValidateAll() error for unset directive")

		emptyEntry := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Entry{
				Entry: "",
			},
		}
		assert(emptyEntry.Validate() != nil, "expected Validate() error for empty entry string")

		invalidCharEntry := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Entry{
				Entry: "invalid char with spaces and @ sign",
			},
		}
		assert(invalidCharEntry.Validate() != nil, "expected Validate() error for invalid entry characters")

		invalidAltLocator := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Alt{
				Alt: &corev3.ResourceLocator{
					Scheme:       corev3.ResourceLocator_XDSTP,
					ResourceType: "", // empty ResourceType violates ResourceLocator constraints
				},
			},
		}
		assert(invalidAltLocator.Validate() != nil, "expected Validate() error when embedded Alt locator fails validation")
		assert(invalidAltLocator.ValidateAll() != nil, "expected ValidateAll() error when embedded Alt locator fails validation")
	}

	// Assertion 6: ResourceLocator_Directive serializes to and deserializes from binary Protobuf wire format satisfying proto.Equal
	{
		orig := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Alt{
				Alt: &corev3.ResourceLocator{
					Scheme:       corev3.ResourceLocator_XDSTP,
					ResourceType: "envoy.config.endpoint.v3.ClusterLoadAssignment",
					Id:           "endpoints-backup",
					Authority:    "example.com",
				},
			},
		}
		wire, err := proto.Marshal(orig)
		assert(err == nil, "proto.Marshal failed")
		assert(len(wire) > 0, "marshaled wire length is 0")

		unmarshaled := &corev3.ResourceLocator_Directive{}
		err = proto.Unmarshal(wire, unmarshaled)
		assert(err == nil, "proto.Unmarshal failed")
		assert(proto.Equal(orig, unmarshaled), "proto.Equal returned false after unmarshal")
		assert(unmarshaled.GetAlt().GetId() == "endpoints-backup", "unmarshaled Alt Id mismatch")
		assert(unmarshaled.GetAlt().GetAuthority() == "example.com", "unmarshaled Alt Authority mismatch")
	}

	// Assertion 7: proto.Clone produces an isolated deep copy of ResourceLocator_Directive where mutating nested fields does not affect the original
	{
		orig := &corev3.ResourceLocator_Directive{
			Directive: &corev3.ResourceLocator_Directive_Alt{
				Alt: &corev3.ResourceLocator{
					Scheme:       corev3.ResourceLocator_XDSTP,
					ResourceType: "envoy.config.listener.v3.Listener",
					Id:           "orig-listener",
				},
			},
		}
		cloned := proto.Clone(orig).(*corev3.ResourceLocator_Directive)
		assert(proto.Equal(orig, cloned), "cloned directive must equal original")

		cloned.GetAlt().Id = "mutated-listener"
		assert(orig.GetAlt().GetId() == "orig-listener", "original Alt locator Id was mutated")
		assert(cloned.GetAlt().GetId() == "mutated-listener", "cloned Alt locator Id was not updated")
	}

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