execmockctx

Documentation

Overview

Package execmockctx provides the minimum interface that the `go.chromium.org/luci/common/exec` library needs to hook into the mocking system provided by `go.chromium.org/luci/common/exec/execmock` without needing to actually link the execmock code (including it's registration of the Simple runner, and the implementation of the http test server) into non-test binaries.

Index

• Variables
• func EnableMockingForThisProcess(mcFactory func(context.Context) (mocker CreateMockInvocation, chatty bool))
• type CreateMockInvocation
  • func GetMockCreator(ctx context.Context) (mocker CreateMockInvocation, chatty bool)
• type MockCriteria
  • func NewMockCriteria(cmd *exec.Cmd) *MockCriteria
• type MockInvocation

Variables

var ErrNoMatchingMock = errors.New("execmock: mocking enabled but no mock matches")

Functions

func EnableMockingForThisProcess

func EnableMockingForThisProcess(mcFactory func(context.Context) (mocker CreateMockInvocation, chatty bool))

EnableMockingForThisProcess is called from execmock to install the mocker service here.

Types

type CreateMockInvocation

type CreateMockInvocation func(mc *MockCriteria, proc **os.Process) (*MockInvocation, error)

CreateMockInvocation encapsulates the entire functionality which "common/exec" needs to call, and which "common/exec/execmock" needs to implement.

This function, if set, should evaluate `mc` against state stored by execmock in `ctx`, and return a MockInvocation if `mc` matches a mock. Note that this will return an error wrapping ErrNoMatchingMock if the context doesn't define a matching mock (which could be due to the user forgetting to Init the context at all).

`proc` should point to the underlying Cmd.Process field; This will be used to expose the Process to the test via Usage.GetProcess().

If this returns (nil, nil) it means that this invocation should be passed through (run as normal).

func GetMockCreator

func GetMockCreator(ctx context.Context) (mocker CreateMockInvocation, chatty bool)

GetMockCreator returns the process wide implementation of CreateMockInvocation, or nil, if mocking is not enabled for this process.

Once this function has been called (i.e. after the first call of ".../common/exec.CommandContext()"), EnableMockingForThisProcess will panic.

If no mocking is configured for this process, returns (nil, false).

type MockCriteria

type MockCriteria struct {
	Args []string
	Env  environ.Env
}

MockCriteria is what execmock uses to look up Entries.

func NewMockCriteria

func NewMockCriteria(cmd *exec.Cmd) *MockCriteria

NewMockCriteria is a convenience function to return a new MockCriteria from a Cmd.

type MockInvocation

type MockInvocation struct {
	// Unique ID of this invocation.
	ID uint64

	// An environment variable ("KEY=Value") which exec should add to
	// the command during invocation.
	//
	// This is "generic" in the sense that it doesn't tie to the specific
	// key/value format that `execmockserver` actually uses, but:
	//   1) this package is internal, so only exec & execmock can use it.
	//   2) this package is separate from execmock specifically to decouple the
	//      need to pull in heavy stuff like "net/http" and "testing" into uses
	//      of "exec".
	//
	// Practically speaking this will always look like
	// "LUCI_EXECMOCK_CTX=localhost:port|invocationID".
	EnvVar string

	// After Wait()'ing for the process, the Cmd runner can call this to get an
	// error (if any) which the Runner returned, as well as the panic stack (if
	// any) from the runner.
	GetErrorOutput func() (panicStack string, err error)
}