github.com/lyft/protoc-gen-star/v2 v2.0.3: InitMockDebugger

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/lyft/protoc-gen-star/v2.InitMockDebugger in pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3
Demonstrate these symbols/APIs:
  - github.com/lyft/protoc-gen-star/v2.InitMockDebugger

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:d8ff28bdadaf4aa852685ff2aee8c2e3dd36c50c89784b8537aa1608e67d3281","contract":["InitMockDebugger returns an initialized MockDebugger with clean initial state","MockDebugger records Log messages to Output reader without setting Failed or Exited","MockDebugger Fail records failure and simulated exit without terminating the process","MockDebugger CheckErr captures error and marks Exited when error is non-nil","MockDebugger Push propagates child failure back to root MockDebugger with prefix"],"goal":"verify github.com/lyft/protoc-gen-star/v2.InitMockDebugger in pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3","kind":"HOW","packages":["pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3"],"schemaVersion":1,"symbols":["github.com/lyft/protoc-gen-star/v2.InitMockDebugger"]},"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/lyft/protoc-gen-star/v2@v2.0.3"],"schemaVersion":1,"subject":"pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3","symbols":["github.com/lyft/protoc-gen-star/v2.InitMockDebugger"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/lyft/protoc-gen-star/v2 v2.0.3

require (
	github.com/spf13/afero v1.3.3 // indirect
	golang.org/x/text v0.3.7 // indirect
	google.golang.org/protobuf v1.23.0 // indirect
)

github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=
github.com/golang/protobuf v1.4.0-rc.4.0.20200313231945-b860323f09d0/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w=
github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvqG2KuDX0=
github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
github.com/lyft/protoc-gen-star/v2 v2.0.3 h1:/3+/2sWyXeMLzKd1bX+ixWKgEMsULrIivpDsuaF441o=
github.com/lyft/protoc-gen-star/v2 v2.0.3/go.mod h1:amey7yeodaJhXSbf/TlLvWiqQfLOSpEk//mLlc+axEk=
github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
github.com/pkg/sftp v1.10.1/go.mod h1:lYOWFsE0bwd1+KfKJaKeuokY15vzFx25BLbzYYoAxZI=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/spf13/afero v1.3.3 h1:p5gZEKLYoL7wh8VrJesMaYeNxdEd1v3cb4irOk9zB54=
github.com/spf13/afero v1.3.3/go.mod h1:5KUK8ByomD5Ti5Artl0RtHeI5pTF7MIDuXL3yY520V4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
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 v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE=
google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
google.golang.org/protobuf v1.23.0 h1:4MY060fB1DLGMB/7MBTLnwQUY6+F09GEiz6SsrNqyzM=
google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

import (
	"errors"
	"io"
	"strings"

	pgs "github.com/lyft/protoc-gen-star/v2"
)

// ErrSampleOperation indicates an intentional test error.
var ErrSampleOperation = errors.New("sample operation failed")

// NewMockDebugger creates a new MockDebugger for unit testing protoc-gen-star modules.
func NewMockDebugger() pgs.MockDebugger {
	return pgs.InitMockDebugger()
}

// CaptureLog writes messages to the mock debugger and returns the accumulated output as a string.
func CaptureLog(d pgs.MockDebugger, messages ...string) (string, error) {
	for _, msg := range messages {
		d.Log(msg)
	}
	out, err := io.ReadAll(d.Output())
	if err != nil {
		return "", err
	}
	return strings.TrimSpace(string(out)), nil
}

// FailWithContext logs a failure on a nested child debugger with the given prefix.
func FailWithContext(d pgs.MockDebugger, prefix, message string) {
	child := d.Push(prefix)
	child.Fail(message)
}

// CheckOperation checks if err is non-nil and passes it to CheckErr.
func CheckOperation(d pgs.MockDebugger, err error, message string) {
	d.CheckErr(err, message)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/lyft/protoc-gen-star/v2.InitMockDebugger in pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/lyft/protoc-gen-star/v2@v2.0.3"
  ],
  "symbols": [
    "github.com/lyft/protoc-gen-star/v2.InitMockDebugger"
  ]
}

package main

import (
	"fmt"
	"io"
	"os"
	"strings"

	pgs "github.com/lyft/protoc-gen-star/v2"
	"sample"
)

func main() {
	fmt.Println("Running contract tests for github.com/lyft/protoc-gen-star/v2.InitMockDebugger...")

	// Assertion 1: InitMockDebugger returns an initialized MockDebugger with clean initial state
	{
		d := sample.NewMockDebugger()
		if d == nil {
			fmt.Fprintf(os.Stderr, "Assertion 1 failed: InitMockDebugger returned nil\n")
			os.Exit(1)
		}
		if d.Failed() {
			fmt.Fprintf(os.Stderr, "Assertion 1 failed: initial Failed() should be false\n")
			os.Exit(1)
		}
		if d.Exited() {
			fmt.Fprintf(os.Stderr, "Assertion 1 failed: initial Exited() should be false\n")
			os.Exit(1)
		}
		if d.Err() != nil {
			fmt.Fprintf(os.Stderr, "Assertion 1 failed: initial Err() should be nil\n")
			os.Exit(1)
		}
		fmt.Println("  ✓ Assertion 1 passed: InitMockDebugger returns an initialized MockDebugger with clean initial state")
	}

	// Assertion 2: MockDebugger records Log messages to Output reader without setting Failed or Exited
	{
		d := pgs.InitMockDebugger()
		d.Log("starting plugin execution")
		d.Logf("processing message %s", "DescriptorProto")

		out, err := io.ReadAll(d.Output())
		if err != nil {
			fmt.Fprintf(os.Stderr, "Assertion 2 failed reading output: %v\n", err)
			os.Exit(1)
		}
		logText := string(out)
		if !strings.Contains(logText, "starting plugin execution") {
			fmt.Fprintf(os.Stderr, "Assertion 2 failed: missing expected log text: %s\n", logText)
			os.Exit(1)
		}
		if !strings.Contains(logText, "processing message DescriptorProto") {
			fmt.Fprintf(os.Stderr, "Assertion 2 failed: missing expected formatted log text: %s\n", logText)
			os.Exit(1)
		}
		if d.Failed() {
			fmt.Fprintf(os.Stderr, "Assertion 2 failed: Failed() should be false after logging\n")
			os.Exit(1)
		}
		if d.Exited() {
			fmt.Fprintf(os.Stderr, "Assertion 2 failed: Exited() should be false after logging\n")
			os.Exit(1)
		}
		fmt.Println("  ✓ Assertion 2 passed: MockDebugger records Log messages to Output reader without setting Failed or Exited")
	}

	// Assertion 3: MockDebugger Fail records failure and simulated exit without terminating the process
	{
		d := pgs.InitMockDebugger()
		d.Fail("unrecoverable generation error")

		if !d.Failed() {
			fmt.Fprintf(os.Stderr, "Assertion 3 failed: expected Failed() to be true\n")
			os.Exit(1)
		}
		if !d.Exited() {
			fmt.Fprintf(os.Stderr, "Assertion 3 failed: expected Exited() to be true\n")
			os.Exit(1)
		}
		if d.ExitCode() != 1 {
			fmt.Fprintf(os.Stderr, "Assertion 3 failed: expected ExitCode() == 1, got %d\n", d.ExitCode())
			os.Exit(1)
		}
		out, _ := io.ReadAll(d.Output())
		if !strings.Contains(string(out), "unrecoverable generation error") {
			fmt.Fprintf(os.Stderr, "Assertion 3 failed: missing expected fail message in output: %s\n", string(out))
			os.Exit(1)
		}
		fmt.Println("  ✓ Assertion 3 passed: MockDebugger Fail records failure and simulated exit without terminating the process")
	}

	// Assertion 4: MockDebugger CheckErr captures error and marks Exited when error is non-nil
	{
		d := pgs.InitMockDebugger()
		sample.CheckOperation(d, sample.ErrSampleOperation, "validating proto AST")

		if d.Err() != sample.ErrSampleOperation {
			fmt.Fprintf(os.Stderr, "Assertion 4 failed: expected Err() == ErrSampleOperation, got %v\n", d.Err())
			os.Exit(1)
		}
		if !d.Exited() {
			fmt.Fprintf(os.Stderr, "Assertion 4 failed: expected Exited() to be true after CheckErr\n")
			os.Exit(1)
		}
		if d.ExitCode() != 1 {
			fmt.Fprintf(os.Stderr, "Assertion 4 failed: expected ExitCode() == 1, got %d\n", d.ExitCode())
			os.Exit(1)
		}
		out, _ := io.ReadAll(d.Output())
		if !strings.Contains(string(out), "[error] validating proto AST: sample operation failed") {
			fmt.Fprintf(os.Stderr, "Assertion 4 failed: unexpected error message in output: %s\n", string(out))
			os.Exit(1)
		}
		fmt.Println("  ✓ Assertion 4 passed: MockDebugger CheckErr captures error and marks Exited when error is non-nil")
	}

	// Assertion 5: MockDebugger Push propagates child failure back to root MockDebugger with prefix
	{
		d := pgs.InitMockDebugger()
		sample.FailWithContext(d, "generator", "syntax violation")

		if !d.Failed() {
			fmt.Fprintf(os.Stderr, "Assertion 5 failed: expected root MockDebugger to be marked Failed() via child\n")
			os.Exit(1)
		}
		if !d.Exited() {
			fmt.Fprintf(os.Stderr, "Assertion 5 failed: expected root MockDebugger to be marked Exited() via child\n")
			os.Exit(1)
		}
		out, _ := io.ReadAll(d.Output())
		if !strings.Contains(string(out), "[generator]syntax violation") {
			fmt.Fprintf(os.Stderr, "Assertion 5 failed: expected prefixed message in output, got: %s\n", string(out))
			os.Exit(1)
		}
		fmt.Println("  ✓ Assertion 5 passed: MockDebugger Push propagates child failure back to root MockDebugger with prefix")
	}

	fmt.Println("All contract assertions passed successfully.")
}