Add lint and go generate steps to CI (#254)

* Add lint and go generate stages to CI

Add CI step to verify `go generate` was run on repo.
Add linter stage to CI along with linter config file,
`.golangci.yml`.
Will likely prefer revive over static-check.

Updated README Contributing section on linting requirements.

Added sequence ordering to make sure lint and go generate stages run
before tests and build.
This way, build and tests are not run on code that could potentially:

    1. not build due to `gofmt` issues;
    2. contain bugs;
    3. have to be re-submitted after issues are fixed; or
    4. contain outdated Win32 syscall or other auto-generated files.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

* Fixed linter issues

Code changes to satisfy linters:

 - Ran `gofmt -s -w` on repo.
 - Broke up long lines.
 - When possible, changed names with incorrect initialism formatting
   - Added exceptions for exported variables.
 - Added exceptions for ALL_CAPS_WITH_UNDERSCORES code.
   - Switched to using `windows` or `syscall` definitions if possible;
     especially if some constants were unused.
 - Added `_ =` to satisfy error linter, and acknowledge that errors are
   being ignored.
 - Switched to using `errors.Is` and `As` in places, elsewhere added
   exceptions if error value was known to be `syscall.Errno`.
 - Removed bare returns.
 - Prevented variables from being overshadowed in certain places
   (ignoring cases of overshadowing `err`).
 - Renamed variables and functions (eg, `len`, `eventMetadata.bytes`) to
   prevent shadowing pre-built functions and imported pacakges.
 - Removed unused method receivers.
 - Added exceptions to certain unused (unexported) constants and
   functions.
   - Deleted unused `once` from `pkg/etw.providerMap`.
 - Renamed `noop.go` files to `main_other.go` or `doc.go`, to better fit
   style recommendations.
 - Added exceptions for non-secure use of SHA1 and weak crypto
   libraries.
 - Replaced `ioutil` with `io` and `os` (and `t.TempDir` in tests).
 - Added fully exhaustive checks for `switch` statements in `pkg/etw`.
 - Defined constant strings for `tools/mkwinsyscall`.
 - Removed unnecessary conversions.
 - Made sure `context.Cancel` was called.

Additionally, added `//go:build windows" constraints on files with
unexported code, since linter will complain about unused code on
non-Windows platforms.

Added a stub `main() {}` for `mkwinsyscall` for non-Windows builds, just in
case `//go:generate` directives are added to OS-agnostic files.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

* PR: spelling, constants, fuzzing

Moved HVSocket fuzzing tests to separate file with go 1.18 build
constraint.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

pkg/etwlogrus/hook.go

@@ -17,7 +17,7 @@ const defaultEventName = "LogrusEntry"
 // ErrNoProvider is returned when a hook is created without a provider being configured.
 var ErrNoProvider = errors.New("no ETW registered provider")
 
-// HookOpt is an option to change the behavior of the Logrus ETW hook
+// HookOpt is an option to change the behavior of the Logrus ETW hook.
 type HookOpt func(*Hook) error
 
 // Hook is a Logrus hook which logs received events to ETW.
@@ -30,16 +30,16 @@ type Hook struct {
 	getEventsOpts func(*logrus.Entry) []etw.EventOpt
 }
 
-// NewHook registers a new ETW provider and returns a hook to log from it. The
-// provider will be closed when the hook is closed.
+// NewHook registers a new ETW provider and returns a hook to log from it.
+// The provider will be closed when the hook is closed.
 func NewHook(providerName string, opts ...HookOpt) (*Hook, error) {
 	opts = append(opts, WithNewETWProvider(providerName))
 
 	return NewHookFromOpts(opts...)
 }
 
-// NewHookFromProvider creates a new hook based on an existing ETW provider. The
-// provider will not be closed when the hook is closed.
+// NewHookFromProvider creates a new hook based on an existing ETW provider.
+// The provider will not be closed when the hook is closed.
 func NewHookFromProvider(provider *etw.Provider, opts ...HookOpt) (*Hook, error) {
 	opts = append(opts, WithExistingETWProvider(provider))
 
@@ -73,7 +73,7 @@ func (h *Hook) validate() error {
 
 // Levels returns the set of levels that this hook wants to receive log entries
 // for.
-func (h *Hook) Levels() []logrus.Level {
+func (*Hook) Levels() []logrus.Level {
 	return logrus.AllLevels
 }
 
@@ -142,7 +142,7 @@ func (h *Hook) Fire(e *logrus.Entry) error {
 	// as a session listening for the event having no available space in its
 	// buffers). Therefore, we don't return the error from WriteEvent, as it is
 	// just noise in many cases.
-	h.provider.WriteEvent(name, opts, fields)
+	_ = h.provider.WriteEvent(name, opts, fields)
 
 	return nil
 }

pkg/etwlogrus/hook_test.go

@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package etwlogrus

pkg/etwlogrus/opts.go

@@ -44,7 +44,7 @@ func WithGetName(f func(*logrus.Entry) string) HookOpt {
 	}
 }
 
-// WithAdditionalEventOpts allows additional ETW event properties (keywords, tags, etc.) to be specified
+// WithEventOpts allows additional ETW event properties (keywords, tags, etc.) to be specified.
 func WithEventOpts(f func(*logrus.Entry) []etw.EventOpt) HookOpt {
 	return func(h *Hook) error {
 		h.getEventsOpts = f