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Flecha

4. Projeto: qualifique o Workspace Guard

O Workspace Guard cria snapshots de um diretório, verifica-os, compara manifestos e pode executar um processo filho somente após a verificação. O código separa comandos, manifesto canônico, modelo e varredura recursiva.

Qualificar importa mais que apenas compilar. Verifique e teste o projeto, crie duas vezes o snapshot de uma árvore fixa e compare os bytes. Altere um arquivo e confirme falha com o status documentado. Execute a partir de um path com espaço. Por fim, examine a limpeza em retornos antecipados e confirme a ordenação da iteração antes da serialização.

O projeto combina strings e coleções próprias, views emprestadas, erros de alocação, imports, filesystem, SHA-256, ambiente e processos sem concentrar todas as responsabilidades em um módulo.

Exemplo testado

Qualifique Workspace Guard como pacote: uso explícito, seleção da raiz, códigos de saída e ajuda determinística.

Trecho em foco

curriculum/main-evidence/projects/workspace_guard/src/main.fl:73–116

curriculum/main-evidence/projects/workspace_guard/src/main.fl (excerpt)
error snapshot_or_verify([]const string values, bool createSnapshot) {
    string root = none;
    stringv manifestPath = "";
    if values.len() == 4 {
        error copyError;
        root, copyError = model::copy_text(values[2].view());
        if copyError != none {
            return copyError;
        }
        manifestPath = values[3].view();
    } else if values.len() == 3 {
        bool present;
        error environmentError;
        root, present, environmentError = environment::get(ROOT_ENVIRONMENT);
        if environmentError != none {
            return environmentError;
        }
        if !present or root.len() == 0 {
            fmt::eprint("workspace_guard: set ");
            fmt::eprintln(ROOT_ENVIRONMENT);
            return model::GuardError.Usage;
        }
        manifestPath = values[2].view();
    } else {
        return model::GuardError.Usage;
    }


    if createSnapshot {
        return commands::snapshot(root.view(), manifestPath);
    }
    return commands::verify(root.view(), manifestPath);
}


void print_usage() {
    fmt::println("workspace_guard - deterministic workspace snapshots");
    fmt::println("");
    fmt::println("usage:");
    fmt::println("  workspace_guard snapshot <root> <manifest>");
    fmt::println("  workspace_guard snapshot <manifest>  # root from FLECHA_GUARD_ROOT");
    fmt::println("  workspace_guard verify <root> <manifest>");
    fmt::println("  workspace_guard verify <manifest>    # root from FLECHA_GUARD_ROOT");
    fmt::println("  workspace_guard diff <old-manifest> <new-manifest>");
    fmt::println("  workspace_guard run <root> <manifest> -- <program> [arguments...]");
}

Este trecho depende dos outros arquivos do pacote. O código completo compilado está disponível abaixo.

Código completo do pacote (7 arquivos)

longbow.toml

longbow.toml
[package]
name = "workspace_guard"
version = "0.1.0"
kind = "program"


[dependencies]

longbow.lock

longbow.lock
{
  "schema": 1,
  "root": "root",
  "packages": [
    {
      "id": "root",
      "identity": "local/workspace_guard",
      "source": {
        "kind": "workspace",
        "path": "."
      },
      "version": "0.1.0",
      "dependencies": {
        "std": "toolchain-std"
      }
    },
    {
      "id": "toolchain-std",
      "identity": "flecha/std",
      "source": {
        "kind": "toolchain"
      },
      "dependencies": {}
    }
  ]
}

src/commands.fl

src/commands.fl
module commands;


@imports
    :: root::manifest
    :: root::model
    :: root::scanner
    :: lib::std::containers::collections
    :: lib::std::fmt
    :: lib::std::process::command;


export error snapshot(stringv rootPath, stringv manifestPath) {
    entries, scanError := scanner::scan(rootPath);
    if scanError != none {
        return scanError;
    }
    writeError := manifest::write(manifestPath, &entries);
    if writeError != none {
        return writeError;
    }
    fmt::print("snapshot: ");
    fmt::print(entries.len());
    fmt::println(" files");
    return none;
}


export error verify(stringv rootPath, stringv manifestPath, bool quiet = false) {
    expected, manifestError := manifest::read(manifestPath);
    if manifestError != none {
        return manifestError;
    }
    actual, scanError := scanner::scan(rootPath);
    if scanError != none {
        return scanError;
    }


    usize differences = compare(&expected, &actual, false);
    if differences != 0 {
        fmt::eprint("workspace_guard: ");
        fmt::eprint(differences);
        fmt::eprintln(" workspace differences");
        return model::GuardError.Mismatch;
    }
    if !quiet {
        fmt::print("verified: ");
        fmt::print(actual.len());
        fmt::println(" files");
    }
    return none;
}


export error diff(stringv oldManifest, stringv newManifest) {
    oldEntries, oldError := manifest::read(oldManifest);
    if oldError != none {
        return oldError;
    }
    newEntries, newError := manifest::read(newManifest);
    if newError != none {
        return newError;
    }


    usize differences = compare(&oldEntries, &newEntries, true);
    fmt::print("diff: ");
    fmt::print(differences);
    fmt::println(" differences");
    return none;
}


usize compare(
    &const collections::Array<model::Entry> expected,
    &const collections::Array<model::Entry> actual,
    bool standardOutput
) {
    expectedValues := expected->view();
    actualValues := actual->view();
    usize expectedIndex = 0;
    usize actualIndex = 0;
    usize differences = 0;


    while expectedIndex < expectedValues.len() or
        actualIndex < actualValues.len() {
        if expectedIndex == expectedValues.len() {
            report("added", actualValues[actualIndex].path(), standardOutput);
            actualIndex++;
            differences++;
            proceed;
        }
        if actualIndex == actualValues.len() {
            report("removed", expectedValues[expectedIndex].path(), standardOutput);
            expectedIndex++;
            differences++;
            proceed;
        }


        expectedPath := expectedValues[expectedIndex].path();
        actualPath := actualValues[actualIndex].path();
        if model::text_less(expectedPath, actualPath) {
            report("removed", expectedPath, standardOutput);
            expectedIndex++;
            differences++;
            proceed;
        }
        if model::text_less(actualPath, expectedPath) {
            report("added", actualPath, standardOutput);
            actualIndex++;
            differences++;
            proceed;
        }


        if !model::same_content(
            &expectedValues[expectedIndex],
            &actualValues[actualIndex]
        ) {
            report("modified", expectedPath, standardOutput);
            differences++;
        }
        expectedIndex++;
        actualIndex++;
    }


    return differences;
}


void report(stringv kind, stringv path, bool standardOutput) {
    if standardOutput {
        fmt::print(kind);
        fmt::print(" ");
        fmt::println(path);
    } else {
        fmt::eprint(kind);
        fmt::eprint(" ");
        fmt::eprintln(path);
    }
}


export (u32, error) run(
    stringv rootPath,
    stringv manifestPath,
    []const string arguments
) {
    verifyError := verify(rootPath, manifestPath, true);
    if verifyError != none {
        return (none, verifyError);
    }
    if arguments.len() == 0 {
        return (none, model::GuardError.Usage);
    }


    executable, copyError := model::copy_text(arguments[0].view());
    if copyError != none {
        return (none, copyError);
    }
    childCommand := command::Command::init(executable);
    loop usize index = 1; index < arguments.len(); index++ {
        argument, argumentError := model::copy_text(arguments[index].view());
        if argumentError != none {
            return (none, argumentError);
        }
        if childCommand.arg(argument) != none {
            return (none, AllocationError.OutOfMemory);
        }
    }


    child, spawnError := childCommand.spawn();
    if spawnError != none {
        return (none, spawnError);
    }
    status, waitError := child.wait();
    if waitError != none {
        return (none, waitError);
    }
    if !status.exited() {
        return (none, model::GuardError.ProcessFailure);
    }
    return (status.detail(), none);
}

src/main.fl

src/main.fl
module main;


@imports
    :: root::commands
    :: root::model
    :: lib::std::fmt
    :: lib::std::os::arguments
    :: lib::std::os::environment;


const stringv ROOT_ENVIRONMENT = "FLECHA_GUARD_ROOT";


i32 main() {
    values, captureError := arguments::capture();
    if captureError != none {
        fmt::eprintln("workspace_guard: cannot capture command-line arguments");
        return 3;
    }
    if values.len() < 2 {
        print_usage();
        return 2;
    }


    command := values[1].view();
    error result = none;
    u32 childStatus = 0;


    if command == "snapshot" or command == "verify" {
        result = snapshot_or_verify(values[:], command == "snapshot");
    } else if command == "diff" and values.len() == 4 {
        result = commands::diff(values[2].view(), values[3].view());
    } else if command == "run" and values.len() >= 6 and values[4] == "--" {
        childStatus, result = commands::run(
            values[2].view(),
            values[3].view(),
            values[5:]
        );
        if result == none {
            return childStatus.cast<i32>;
        }
    } else if command == "help" or command == "--help" or command == "-h" {
        print_usage();
        return 0;
    } else {
        result = model::GuardError.Usage;
    }


    if result == none {
        return 0;
    }
    if result == model::GuardError.Usage {
        print_usage();
        return 2;
    }
    if result == model::GuardError.InvalidManifest {
        fmt::eprintln("workspace_guard: invalid manifest");
        return 4;
    }
    if result == model::GuardError.Mismatch {
        return 5;
    }
    if result == model::GuardError.UnsupportedEntry {
        return 6;
    }
    if result == model::GuardError.ProcessFailure {
        fmt::eprintln("workspace_guard: child process terminated abnormally");
        return 7;
    }


    fmt::eprintln("workspace_guard: operation failed");
    return 3;
}


error snapshot_or_verify([]const string values, bool createSnapshot) {
    string root = none;
    stringv manifestPath = "";
    if values.len() == 4 {
        error copyError;
        root, copyError = model::copy_text(values[2].view());
        if copyError != none {
            return copyError;
        }
        manifestPath = values[3].view();
    } else if values.len() == 3 {
        bool present;
        error environmentError;
        root, present, environmentError = environment::get(ROOT_ENVIRONMENT);
        if environmentError != none {
            return environmentError;
        }
        if !present or root.len() == 0 {
            fmt::eprint("workspace_guard: set ");
            fmt::eprintln(ROOT_ENVIRONMENT);
            return model::GuardError.Usage;
        }
        manifestPath = values[2].view();
    } else {
        return model::GuardError.Usage;
    }


    if createSnapshot {
        return commands::snapshot(root.view(), manifestPath);
    }
    return commands::verify(root.view(), manifestPath);
}


void print_usage() {
    fmt::println("workspace_guard - deterministic workspace snapshots");
    fmt::println("");
    fmt::println("usage:");
    fmt::println("  workspace_guard snapshot <root> <manifest>");
    fmt::println("  workspace_guard snapshot <manifest>  # root from FLECHA_GUARD_ROOT");
    fmt::println("  workspace_guard verify <root> <manifest>");
    fmt::println("  workspace_guard verify <manifest>    # root from FLECHA_GUARD_ROOT");
    fmt::println("  workspace_guard diff <old-manifest> <new-manifest>");
    fmt::println("  workspace_guard run <root> <manifest> -- <program> [arguments...]");
}

src/manifest.fl

src/manifest.fl
module manifest;


@imports
    :: root::model
    :: lib::std::containers::collections
    :: lib::std::encoding::hex
    :: lib::std::io::buffered
    :: lib::std::io::errors as io_errors
    :: lib::std::io::file
    :: lib::std::io::filesystem
    :: lib::std::text::strings
    :: lib::std::text::utf8;


const stringv HEADER = "FLECHA-WORKSPACE-SNAPSHOT\t1\n";
const usize WRITE_CAPACITY = 8192;


export error write(
    stringv destination,
    &const collections::Array<model::Entry> entries
) {
    present, existsError := filesystem::exists(destination);
    if existsError != none {
        return existsError;
    }
    if present {
        return io_errors::IoError.AlreadyExists;
    }


    options := build file::OpenOptions {
        self.write = true;
        self.createNew = true;
    };
    output, openError := file::File::open(destination, options);
    if openError != none {
        return openError;
    }


    error result = none;
    {
        adapter := output.writer();
        writer, writerError :=
            buffered::BufferedWriter::withCapacity(adapter, WRITE_CAPACITY);
        if writerError != none {
            result = writerError;
        } else {
            result = write_contents(&writer, entries);
        }
    }


    if result == none {
        result = output.flush();
    }
    closeError := output.close();
    if result == none {
        result = closeError;
    }


    if result != none {
        error _ = filesystem::remove_file(destination);
    }
    return result;
}


error write_contents(
    &buffered::BufferedWriter writer,
    &const collections::Array<model::Entry> entries
) {
    error writeError = writer->writeAll(HEADER.cast<[]const u8>);
    if writeError != none {
        return writeError;
    }


    values := entries->view();
    loop usize index = 0; index < values.len(); index++ {
        pathHex, pathError := hex::encode(values[index].path());
        if pathError != none {
            return pathError;
        }
        sizeText, sizeError :=
            strings::int_to_string<u64>(values[index].byteSize());
        if sizeError != none {
            return sizeError;
        }


        writeError = writer->writeAll(
            values[index].hash().cast<[]const u8>
        );
        if writeError == none {
            writeError = writer->writeAll("\t".cast<[]const u8>);
        }
        if writeError == none {
            writeError = writer->writeAll(sizeText.view().cast<[]const u8>);
        }
        if writeError == none {
            writeError = writer->writeAll("\t".cast<[]const u8>);
        }
        if writeError == none {
            writeError = writer->writeAll(pathHex.view().cast<[]const u8>);
        }
        if writeError == none {
            writeError = writer->writeAll("\n".cast<[]const u8>);
        }
        if writeError != none {
            return writeError;
        }
    }


    return writer->flush();
}


export (collections::Array<model::Entry>, error) read(stringv sourcePath) {
    contents, readError := filesystem::read_file(sourcePath);
    if readError != none {
        return (collections::Array<model::Entry>::init(), readError);
    }
    return parse(contents.view());
}


(collections::Array<model::Entry>, error) parse(stringv contents) {
    entries := collections::Array<model::Entry>::init();
    if contents.len() < HEADER.len() or
        contents.substr(0, HEADER.len()) != HEADER {
        return (entries, model::GuardError.InvalidManifest);
    }


    u32 offset = HEADER.len();
    while offset < contents.len() {
        u32 end = offset;
        while end < contents.len() and contents[end] != '\n' {
            end++;
        }
        if end == contents.len() or end == offset {
            return (entries, model::GuardError.InvalidManifest);
        }


        entry, entryError := parse_line(contents.substr(offset, end - offset));
        if entryError != none {
            return (entries, entryError);
        }
        if !entries.empty() {
            {
                values := entries.view();
                if !model::text_less(
                    values[values.len() - 1].path(),
                    entry.path()
                ) {
                    return (entries, model::GuardError.InvalidManifest);
                }
            }
        }
        pushError := entries.push(entry);
        if pushError != none {
            return (entries, pushError);
        }
        offset = end + 1;
    }


    return (entries, none);
}


(model::Entry, error) parse_line(stringv line) {
    u32 first = line.len();
    u32 second = line.len();
    loop u32 index = 0; index < line.len(); index++ {
        if line[index] != '\t' {
            proceed;
        }
        if first == line.len() {
            first = index;
        } else if second == line.len() {
            second = index;
        } else {
            return (none, model::GuardError.InvalidManifest);
        }
    }
    if first == 0 or second <= first + 1 or second + 1 >= line.len() {
        return (none, model::GuardError.InvalidManifest);
    }


    digestText := line.substr(0, first);
    sizeText := line.substr(first + 1, second - first - 1);
    pathText := line.substr(second + 1, line.len() - second - 1);


    digestBytes, digestDecodeError := hex::decode_to_bytes(digestText);
    if digestDecodeError != none or digestBytes.len() != 32 {
        return (none, model::GuardError.InvalidManifest);
    }
    canonicalDigest, digestEncodeError := hex::encode_bytes(digestBytes[:]);
    if digestEncodeError != none {
        return (none, digestEncodeError);
    }
    if canonicalDigest.view() != digestText {
        return (none, model::GuardError.InvalidManifest);
    }


    size, sizeParseError := strings::stringv_to_int<u64>(sizeText);
    if sizeParseError != none {
        return (none, model::GuardError.InvalidManifest);
    }
    canonicalSize, sizeFormatError := strings::int_to_string<u64>(size);
    if sizeFormatError != none {
        return (none, sizeFormatError);
    }
    if canonicalSize.view() != sizeText {
        return (none, model::GuardError.InvalidManifest);
    }


    pathValue, pathDecodeError := hex::decode(pathText);
    if pathDecodeError != none or utf8::validate(pathValue.view()) != none or
        !model::valid_relative_path(pathValue.view()) {
        return (none, model::GuardError.InvalidManifest);
    }
    canonicalPath, pathEncodeError := hex::encode(pathValue.view());
    if pathEncodeError != none {
        return (none, pathEncodeError);
    }
    if canonicalPath.view() != pathText {
        return (none, model::GuardError.InvalidManifest);
    }


    return (model::Entry::init(pathValue, canonicalDigest, size), none);
}

src/model.fl

src/model.fl
module model;


@imports
    :: lib::std::text::strings;


export error GuardError {
    Usage,
    InvalidManifest,
    UnsupportedEntry,
    Mismatch,
    ProcessFailure
}


export structure Entry {
    string relativePath;
    string digest;
    u64 size;
};


Entry Entry::init(string relativePath, string digest, u64 size) override {
    return build Entry {
        self.relativePath = relativePath;
        self.digest = digest;
        self.size = size;
    };
}


stringv Entry::path(&const self) <-self {
    return self->relativePath.view();
}


stringv Entry::hash(&const self) <-self {
    return self->digest.view();
}


u64 Entry::byteSize(&const self) {
    return self->size;
}


export bool text_less(stringv left, stringv right) {
    u32 common = left.len();
    if right.len() < common {
        common = right.len();
    }


    loop u32 index = 0; index < common; index++ {
        if left[index] < right[index] {
            return true;
        }
        if left[index] > right[index] {
            return false;
        }
    }


    return left.len() < right.len();
}


export bool entry_less(&const Entry left, &const Entry right) {
    return text_less(left->path(), right->path());
}


export bool same_content(&const Entry left, &const Entry right) {
    return left->byteSize() == right->byteSize() and
        left->hash() == right->hash();
}


export (string, error) copy_text(stringv value) {
    return strings::string_from_bytes(value.cast<[]const u8>);
}


export (string, error) child_path(stringv parent, stringv name) {
    if parent.len() == 0 {
        return copy_text(name);
    }


    usize capacity = parent.len().cast<usize> + name.len().cast<usize> + 1;
    if capacity <= parent.len().cast<usize> {
        return (none, AllocationError.OutOfMemory);
    }


    builder, allocationError := strings::StringBuilder::withCapacity(capacity);
    if allocationError != none {
        return (none, allocationError);
    }
    if builder.append(parent) != none or builder.appendChar('/') != none or
        builder.append(name) != none {
        return (none, AllocationError.OutOfMemory);
    }


    return builder.toString();
}


export bool valid_relative_path(stringv value) {
    if value.len() == 0 or value[0] == '/' or
        value[value.len() - 1] == '/' {
        return false;
    }


    u32 segmentStart = 0;
    loop u32 index = 0; index <= value.len(); index++ {
        if index < value.len() {
            const char BYTE = value[index];
            const u8 BYTE_VALUE = BYTE.cast<u8>;
            if BYTE_VALUE < 32 or BYTE_VALUE == 127 or BYTE == '\\' or
                BYTE == ':' or BYTE == '*' or BYTE == '?' or BYTE == '"' or
                BYTE == '<' or BYTE == '>' or BYTE == '|' {
                return false;
            }
            if BYTE != '/' {
                proceed;
            }
        }


        const u32 LENGTH = index - segmentStart;
        if LENGTH == 0 {
            return false;
        }
        segment := value.substr(segmentStart, LENGTH);
        if segment == "." or segment == ".." {
            return false;
        }
        segmentStart = index + 1;
    }


    return true;
}

src/scanner.fl

src/scanner.fl
module scanner;


@imports
    :: root::model
    :: lib::std::containers::collections
    :: lib::std::cryptography::sha2
    :: lib::std::encoding::hex
    :: lib::std::fmt
    :: lib::std::io::buffered
    :: lib::std::io::file
    :: lib::std::io::path
    :: lib::std::text::utf8;


const usize READ_CAPACITY = 32768;


export (collections::Array<model::Entry>, error) scan(stringv rootPath) {
    entries := collections::Array<model::Entry>::init();
    scanError := collect(rootPath, "", &entries);
    if scanError != none {
        return (entries, scanError);
    }


    entries.sortBy(model::entry_less);
    return (entries, none);
}


error collect(
    stringv rootPath,
    stringv relativePath,
    &collections::Array<model::Entry> entries
) {
    string directoryPath = none;
    if relativePath.len() == 0 {
        error copyError;
        directoryPath, copyError = model::copy_text(rootPath);
        if copyError != none {
            return copyError;
        }
    } else {
        error joinError;
        directoryPath, joinError = path::join(rootPath, relativePath);
        if joinError != none {
            return joinError;
        }
    }


    directory, openError := file::Directory::open(directoryPath.view());
    if openError != none {
        fmt::eprint("workspace_guard: cannot open directory: ");
        fmt::eprintln(directoryPath.view());
        return openError;
    }


    while true {
        entry, present, readError := directory.next();
        if readError != none {
            return readError;
        }
        if !present {
            break;
        }
        if utf8::validate(entry.name()) != none {
            fmt::eprintln("workspace_guard: non-UTF-8 path is unsupported");
            return model::GuardError.UnsupportedEntry;
        }


        childRelative, relativeError :=
            model::child_path(relativePath, entry.name());
        if relativeError != none {
            return relativeError;
        }
        if !model::valid_relative_path(childRelative.view()) {
            fmt::eprint("workspace_guard: non-portable path: ");
            fmt::eprintln(childRelative.view());
            return model::GuardError.UnsupportedEntry;
        }


        if entry.kind() == file::EntryType.Directory {
            recurseError := collect(rootPath, childRelative.view(), entries);
            if recurseError != none {
                return recurseError;
            }
            proceed;
        }
        if entry.kind() != file::EntryType.File {
            fmt::eprint("workspace_guard: unsupported entry: ");
            fmt::eprintln(childRelative.view());
            return model::GuardError.UnsupportedEntry;
        }


        actualPath, joinError := path::join(rootPath, childRelative.view());
        if joinError != none {
            return joinError;
        }
        digest, size, hashError := hash_file(actualPath.view());
        if hashError != none {
            fmt::eprint("workspace_guard: cannot hash file: ");
            fmt::eprintln(childRelative.view());
            return hashError;
        }


        pushError := entries->push(
            model::Entry::init(childRelative, digest, size)
        );
        if pushError != none {
            return pushError;
        }
    }


    return directory.close();
}


(string, u64, error) hash_file(stringv filePath) {
    input, openError := file::File::open(filePath, file::OpenOptions::readOnly());
    if openError != none {
        return (none, none, openError);
    }


    hasher := sha2::Sha256::init();
    u64 total = 0;
    error result = none;
    {
        adapter := input.reader();
        reader, readerError :=
            buffered::BufferedReader::withCapacity(adapter, READ_CAPACITY);
        if readerError != none {
            return (none, none, readerError);
        }


        [32768]u8 chunk = none;
        while true {
            count, readError := reader.read(chunk[:]);
            if count > 0 {
                const u64 NEXT = total + count.cast<u64>;
                if NEXT < total {
                    return (none, none, AllocationError.OutOfMemory);
                }
                total = NEXT;
                result = hasher.update(chunk[:count]);
                if result != none {
                    return (none, none, result);
                }
            }
            if readError != none {
                return (none, none, readError);
            }
            if count == 0 {
                break;
            }
        }
    }


    closeError := input.close();
    if closeError != none {
        return (none, none, closeError);
    }
    digest, digestError := hasher.finalize();
    if digestError != none {
        return (none, none, digestError);
    }
    encoded, encodeError := hex::encode_bytes(digest.bytes());
    return (encoded, total, encodeError);
}

O ramo selecionado coordena os módulos já separados de scanner, manifesto e processo. O pacote completo é necessário porque o comportamento resulta da interação entre esses módulos, não do trecho isolado.

Comandos

Comandos
longbow check curriculum/main-evidence/projects/workspace_guard
longbow test curriculum/main-evidence/projects/workspace_guard
longbow build curriculum/main-evidence/projects/workspace_guard
longbow run curriculum/main-evidence/projects/workspace_guard -- help

Saída esperada

Saída esperada
workspace_guard - deterministic workspace snapshots


usage:
  workspace_guard snapshot <root> <manifest>
  workspace_guard snapshot <manifest>  # root from FLECHA_GUARD_ROOT
  workspace_guard verify <root> <manifest>
  workspace_guard verify <manifest>    # root from FLECHA_GUARD_ROOT
  workspace_guard diff <old-manifest> <new-manifest>
  workspace_guard run <root> <manifest> -- <program> [arguments...]
status de saída: 0

Referência relacionada: /examples/workspace_guard/src/main/.

Trilha concluída

Seção intitulada “Trilha concluída”

Continue em Avançado: contratos de propriedade e builds determinísticos.