bintest

package module
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 Go to latest Published: Aug 20, 2024 License: MIT Imports: 24 Imported by: 1

README

Bintest

⚠ This is an open-sourced tool we use internally. You're welcome to use it, but we are unable to provide support.

Documentation

A set of tools for generating fake binaries that can be used for testing. A binary is compiled and then can be orchestrated from your test suite and later checked for assertions.

Mocks can communicate and respond in real-time with the tests that are calling them, which allows for testing complicated dependencies. See https://github.com/buildkite/agent/tree/master/bootstrap/integration for how we use it to test buildkite-agent's bootstrap process.

Mocks

Mocks are your typical mock object, but as an executable that your code can shell out to and then later test assertions on.

agent, err := bintest.NewMock("buildkite-agent")
if err != nil {
  t.Fatal(err)
}

agent.
  Expect("meta-data", "exists", "buildkite:git:commit").
  AndExitWith(1)
agent.
  Expect("meta-data", "set", mock.MatchAny()).
  AndExitWith(0)
agent.
  Expect("meta-data", "set", "buildkite:git:branch", mock.MatchAny()).
  AndExitWith(0)

agent.CheckAndClose(t)

Proxies

Proxies are what power Mocks.

// Compile a proxy for the git command that echos some debug
proxy, err := bintest.CompileProxy("git")
if err != nil {
  log.Fatal(err)
}

// call the proxy like a normal binary
go fmt.Println(exec.Command("git", "test", "arguments").CombinedOutput())

// handle invocations of the proxy binary
for call := range proxy.Ch {
  fmt.Fprintln(call.Stdout, "Llama party! 🎉")
  call.Exit(0)
}

// Llama party! 🎉

Credit

Inspired by bats-mock and go-binmock.

Documentation

Index

Examples

Constants

View Source 
const (
	InfiniteTimes = -1
)
View Source 
const (
	ServerEnvVar = `BINTEST_PROXY_SERVER`
)

Variables

View Source 
var (
	Debug bool
)
View Source 
var ErrNoExpectationsMatch = errors.New("No expectations match")

Functions

func AnyArguments 

func AnyArguments() func(arg ...string) ArgumentsMatchResult

AnyArguments is a helper function for matching any argument set in WithMatcherFunc

func ExpectEnv 

func ExpectEnv(t *testing.T, environ []string, expect ...string) error

ExpectEnv asserts that certain environment vars/values exist, otherwise an error is reported to T and a matching error is returned (for Before)

func FormatInterfaces 

func FormatInterfaces(a []interface{}) string

FormatInterfaces formats a slice of interface{} as quoted comma-separated arguments

func FormatStrings 

func FormatStrings(a []string) string

FormatStrings formats a slice of strings as quoted comma-separated arguments

func GetEnv 

func GetEnv(key string, environ []string) (string, bool)

GetEnv returns the value for a given env in the invocation

func StopServer 

func StopServer() error

StopServer stops the shared http server instance

Types

type Arguments 

type Arguments []interface{}

func ArgumentsFromStrings 

func ArgumentsFromStrings(s []string) Arguments

func (Arguments) Match 

func (a Arguments) Match(x ...string) (result ArgumentsMatchResult)

func (Arguments) String 

func (a Arguments) String() string

type ArgumentsMatchResult 

type ArgumentsMatchResult struct {
	IsMatch     bool
	MatchCount  int
	Explanation string
}

type Call 

type Call struct {
	PID  int
	Name string
	Args []string
	Env  []string
	Dir  string

	// Stdout is the output writer to send stdout to in the proxied binary
	Stdout io.WriteCloser `json:"-"`

	// Stderr is the output writer to send stdout to in the proxied binary
	Stderr io.WriteCloser `json:"-"`

	// Stdin is the input reader for stdin from the proxied binary
	Stdin io.ReadCloser `json:"-"`
	// contains filtered or unexported fields
}

Call is created for every call to the proxied binary

func (*Call) Exit 

func (c *Call) Exit(code int)

Exit finishes the call and the proxied binary returns the exit code

func (*Call) Fatal 

func (c *Call) Fatal(err error)

Fatal exits the call and returns the passed error. If it's a exec.ExitError the exit code is used

func (*Call) GetEnv 

func (c *Call) GetEnv(key string) string

func (*Call) IsDone 

func (c *Call) IsDone() bool

IsDone is a non-blocking thread-safe checks whether the call is done.

func (*Call) Passthrough 

func (c *Call) Passthrough(path string)

Passthrough invokes another local binary and returns the results

func (*Call) PassthroughWithTimeout 

func (c *Call) PassthroughWithTimeout(path string, timeout time.Duration)

PassthroughWithTimeout invokes another local binary and returns the results, if execution doesn't finish before the timeout the command is killed and an error is returned

type Client 

type Client struct {
	Debug bool
	URL   string

	Args []string
	Dir  string
	Env  []string
	PID  int

	Stdin  io.ReadCloser
	Stdout io.WriteCloser
	Stderr io.WriteCloser
}

func NewClient 

func NewClient(URL string) *Client

func NewClientFromEnv 

func NewClientFromEnv() *Client

func (*Client) Run 

func (c *Client) Run() int

Run the client, panics on error and returns an exit code on success

type Expectation 

type Expectation struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

Expectation is used for setting expectations

func (*Expectation) AndCallFunc 

func (e *Expectation) AndCallFunc(f func(*Call)) *Expectation

AndCallFunc causes a middleware function to be called before invocation

func (*Expectation) AndExitWith 

func (e *Expectation) AndExitWith(code int) *Expectation

AndExitWith causes the invoker to finish with an exit code of code

func (*Expectation) AndPassthroughToLocalCommand 

func (e *Expectation) AndPassthroughToLocalCommand(path string) *Expectation

AndPassthroughToLocalCommand causes the invoker to defer to a local command

func (*Expectation) AndWriteToStderr 

func (e *Expectation) AndWriteToStderr(s string) *Expectation

AndWriteToStderr causes the invoker to output s to stderr. This resets any passthrough path set

func (*Expectation) AndWriteToStdout 

func (e *Expectation) AndWriteToStdout(s string) *Expectation

AndWriteToStdout causes the invoker to output s to stdout. This resets any passthrough path set

func (*Expectation) AtLeastOnce 

func (e *Expectation) AtLeastOnce() *Expectation

AtLeastOnce expects a minimum invocations of 0 and a max of InfinityTimes

func (*Expectation) Check 

func (e *Expectation) Check(t TestingT) bool

Check evaluates the expectation and outputs failures to the provided testing.T object

func (*Expectation) Exactly 

func (e *Expectation) Exactly(expect int) *Expectation

Exactly expects exactly n invocations of this expectation

func (*Expectation) Max 

func (e *Expectation) Max(expect int) *Expectation

Max expects a maximum of n invocations of this expectation, defaults to 1

func (*Expectation) Min 

func (e *Expectation) Min(expect int) *Expectation

Min expects a minimum of n invocations of this expectation

func (*Expectation) NotCalled 

func (e *Expectation) NotCalled() *Expectation

NotCalled is a shortcut for Exactly(0)

func (*Expectation) Once 

func (e *Expectation) Once() *Expectation

Once is a shortcut for Exactly(1)

func (*Expectation) Optionally 

func (e *Expectation) Optionally() *Expectation

Optionally is a shortcut for Min(0)

func (*Expectation) String 

func (e *Expectation) String() string

func (*Expectation) WithAnyArguments 

func (e *Expectation) WithAnyArguments() *Expectation

WithAnyArguments causes the expectation to accept any arguments via a MatcherFunc

func (*Expectation) WithMatcherFunc 

func (e *Expectation) WithMatcherFunc(f func(arg ...string) ArgumentsMatchResult) *Expectation

WithMatcherFunc provides a custom matcher for argument sets, for instance matching variable amounts of arguments

func (*Expectation) WithStdin 

func (e *Expectation) WithStdin(match interface{}) *Expectation

WithStdin sets an expectation on the stdin received by the command.

type ExpectationResult 

type ExpectationResult struct {
	Arguments            []string
	Expectation          *Expectation
	ArgumentsMatchResult ArgumentsMatchResult
	CallCountMatch       bool
}

ExpectationResult is the result of a set of Arguments applied to an Expectation

func (ExpectationResult) Explain 

func (r ExpectationResult) Explain() string

Explain returns an explanation of why the Expectation didn't match

type ExpectationResultSet 

type ExpectationResultSet []ExpectationResult

ExpectationResultSet is a collection of ExpectationResult

func (ExpectationResultSet) ClosestMatch 

func (r ExpectationResultSet) ClosestMatch() ExpectationResult

ClosestMatch returns the ExpectationResult that was the closest match (if not the exact) This is used for suggesting what the user might have meant

func (ExpectationResultSet) Match 

func (r ExpectationResultSet) Match() (*Expectation, error)

Match returns the first Expectation that matches exactly, or ErrNoExpectationsMatch if none match.

type ExpectationSet 

type ExpectationSet []*Expectation

ExpectationSet is a set of expectations

func (ExpectationSet) ForArguments 

func (exp ExpectationSet) ForArguments(args ...string) (result ExpectationResultSet)

ForArguments applies arguments to the expectations and returns the results

type Invocation 

type Invocation struct {
	Args        []string
	Env         []string
	Dir         string
	Expectation *Expectation
}

Invocation is a call to the binary

type Matcher 

type Matcher interface {
	fmt.Stringer
	Match(s string) (bool, string)
}

func MatchAny 

func MatchAny() Matcher

func MatchPattern 

func MatchPattern(pattern string) Matcher

type MatcherFunc 

type MatcherFunc struct {
	// contains filtered or unexported fields
}

func (MatcherFunc) Match 

func (mf MatcherFunc) Match(s string) (bool, string)

func (MatcherFunc) String 

func (mf MatcherFunc) String() string

type Mock 

type Mock struct {
	sync.Mutex

	// Name of the binary
	Name string

	// Path to the bintest binary
	Path string
	// contains filtered or unexported fields
}

Mock provides a wrapper around a Proxy for testing

func NewMock 

func NewMock(path string) (*Mock, error)

NewMock builds a new Mock, or an error if the bintest fails to compile

func NewMockFromTestMain 

func NewMockFromTestMain(path string) (*Mock, error)

func (*Mock) Before 

func (m *Mock) Before(f func(i Invocation) error) *Mock

Before adds a middleware that is run before the Invocation is dispatched

func (*Mock) Check 

func (m *Mock) Check(t TestingT) bool

Check that all assertions are met and that there aren't invocations that don't match expectations

func (*Mock) CheckAndClose 

func (m *Mock) CheckAndClose(t TestingT) error

func (*Mock) Close 

func (m *Mock) Close() error

func (*Mock) Expect 

func (m *Mock) Expect(args ...interface{}) *Expectation

Expect creates an expectation that the mock will be called with the provided args

func (*Mock) ExpectAll 

func (m *Mock) ExpectAll(argSlices [][]interface{})

ExpectAll is a shortcut for adding lots of expectations

func (*Mock) IgnoreUnexpectedInvocations 

func (m *Mock) IgnoreUnexpectedInvocations() *Mock

IgnoreUnexpectedInvocations allows for invocations without matching call expectations to just silently return 0 and no output

func (*Mock) PassthroughToLocalCommand 

func (m *Mock) PassthroughToLocalCommand() *Mock

PassthroughToLocalCommand executes the mock name as a local command (looked up in PATH) and then passes the result as the result of the mock. Useful for assertions that commands happen, but where you want the command to actually be executed.

type Proxy 

type Proxy struct {
	// Ch is the channel of calls
	Ch chan *Call

	// Path is the full path to the compiled binproxy file
	Path string

	// The server that the proxy uses to communicate with the binary
	Server *Server

	// A count of how many calls have been made
	CallCount int64
	// contains filtered or unexported fields
}

Proxy provides a way to programatically respond to invocations of a binary

func CompileProxy 

func CompileProxy(path string) (*Proxy, error)

CompileProxy generates a mock binary at the provided path. If just a filename is provided a temp directory is created.

Example 
// create a proxy for the git command that echos some debug
p, err := bintest.CompileProxy("git")
if err != nil {
	log.Fatal(err)
}

// call the proxy like a normal binary in the background
cmd := exec.Command(p.Path, "rev-parse")
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr

// windows needs all the environment variables
cmd.Env = append(os.Environ(), `MY_MESSAGE=Llama party! 🎉`)

if err := cmd.Start(); err != nil {
	_ = p.Close()
	log.Fatal(err)
}

// handle invocations of the proxy binary
call := <-p.Ch
fmt.Fprintln(call.Stdout, call.GetEnv(`MY_MESSAGE`))
call.Exit(0)

// wait for the command to finish
_ = cmd.Wait()

if err := p.Close(); err != nil {
	log.Fatal(err)
}

Output:

Llama party! 🎉

func LinkTestBinaryAsProxy 

func LinkTestBinaryAsProxy(path string) (*Proxy, error)

LinkTestBinaryAsProxy uses the current binary as a Proxy rather than compiling one directly This speeds things up considerably, but requires some code to be injected in TestMain

Example 
// create a proxy for the git command that echos some debug
p, err := bintest.LinkTestBinaryAsProxy("git")
if err != nil {
	log.Fatal(err)
}

// call the proxy like a normal binary in the background
cmd := exec.Command(p.Path, "rev-parse")
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr

// windows needs all the environment variables
cmd.Env = os.Environ()
cmd.Env = append(cmd.Env, p.Environ()...)
cmd.Env = append(cmd.Env, `MY_MESSAGE=Llama party! 🎉`)

if err := cmd.Start(); err != nil {
	log.Fatal(err)
}

// handle invocations of the proxy binary
call := <-p.Ch
fmt.Fprintln(call.Stdout, call.GetEnv(`MY_MESSAGE`))
call.Exit(0)

// wait for the command to finish
if err := cmd.Wait(); err != nil {
	log.Fatal(err)
}

// cleanup the proxy
if err := p.Close(); err != nil {
	log.Fatal(err)
}

Output:

Llama party! 🎉

func (*Proxy) Close 

func (p *Proxy) Close() error

Close the proxy and remove the temp directory.

func (*Proxy) Environ 

func (p *Proxy) Environ() []string

Environ returns environment variables required to invoke the proxy

type Server 

type Server struct {
	net.Listener
	URL string
	// contains filtered or unexported fields
}

func StartServer 

func StartServer() (*Server, error)

StartServer starts an instance of a proxy server

func (*Server) ServeHTTP 

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request)

type TestingT 

type TestingT interface {
	Logf(format string, args ...interface{})
	Errorf(format string, args ...interface{})
}

TestingT is an interface for *testing.T

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