godev/cmd/telemetrygodev: skip tests in unintended environments

golang.org/x/telemetry/godev is a module that hosts code for the
telemetry.go.dev service. This module is not intended to work
standalone, but assumes the whole telemetry repo is cloned.
Running this service on platforms like android, ios, etc is not
our focus either. The production service is likely running on linux,
but we also want to be able to test, develop on darwin or windows.

* Skip platforms that are not likely used by x/telemetry/godev
contributors. e.g.  android, ios, ...
* Skip if 'go' is not available.
* Run go list to find x/telemetry module. When go list runs from
a directory under x/telemetry/godev, the command will return the
replaced directory path, which is also the repo root.

For golang/go#65549
For golang/go#65258

Change-Id: I88f5f51bd0f2c355975127e1fa9559394e307f97
Reviewed-on: https://go-review.googlesource.com/c/telemetry/+/563358
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Robert Findley <[email protected]>
Auto-Submit: Hyang-Ah Hana Kim <[email protected]>
Run-TryBot: Hyang-Ah Hana Kim <[email protected]>

Author: hyangah

godev/cmd/telemetrygodev/main_test.go

@@ -12,15 +12,71 @@ import (
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"testing"
 
 	"golang.org/x/telemetry"
 	"golang.org/x/telemetry/godev/internal/config"
 	tconfig "golang.org/x/telemetry/internal/config"
+	"golang.org/x/telemetry/internal/testenv"
 )
 
+func TestMain(m *testing.M) {
+	if !canRunGoDevModuleTests() {
+		return
+	}
+	os.Exit(m.Run())
+}
+
+// First class ports, https://go.dev/wiki/PortingPolicy, excluding 386 and arm.
+var onSupportedPlatform = map[string]bool{
+	"darwin/amd64":  true,
+	"darwin/arm64":  true,
+	"linux/amd64":   true,
+	"linux/arm64":   true,
+	"windows/amd64": true,
+}
+
+// canRunGoDevModuleTests returns whether the current test environment
+// is suitable for golang.org/x/telemetry/godev module tests.
+func canRunGoDevModuleTests() bool {
+	// Even though telemetry.go.dev runs on linux,
+	// we should be still able to debug and test telemetry.go.dev on
+	// contributors' machines locally.
+	if goosarch := runtime.GOOS + "/" + runtime.GOARCH; !onSupportedPlatform[goosarch] {
+		return false
+	}
+	// Must be able to run 'go'.
+	if err := testenv.HasGo(); err != nil {
+		return false
+	}
+
+	// Our tests must run from the repository source, not from module cache.
+	// Check golang.org/x/telemetry directory is accessible and has go.mod and config/config.json.
+	output, err := exec.Command("go", "list", "-f", "{{.Dir}}", "golang.org/x/telemetry").Output()
+	if err != nil {
+		return false
+	}
+	xTelemetryDir := string(bytes.TrimSpace(output))
+	if xTelemetryDir == "" {
+		return false
+	}
+	if _, err := os.Stat(filepath.Join(xTelemetryDir, "go.mod")); err != nil {
+		return false
+	}
+	// config/config.json is in the golang.org/x/telemetry/config module, so
+	// this doesn't hold from e.g. GOMODCACHE.
+	if _, err := os.Stat(filepath.Join(xTelemetryDir, "config", "config.json")); err != nil {
+		return false
+	}
+
+	return true
+}
+
 // If telemetry_url is configured, TestPaths may be used as a basic push test.
 var telemetryURL = flag.String("telemetry_url", "", "url of the telemetry instance to test")
 

internal/testenv/testenv.go

@@ -31,7 +31,8 @@ var (
 	hasGoErr  error
 )
 
-func hasGo() error {
+// HasGo checks whether the current system has 'go'.
+func HasGo() error {
 	hasGoOnce.Do(func() {
 		cmd := exec.Command("go", "env", "GOROOT")
 		out, err := cmd.Output()
@@ -50,7 +51,7 @@ func hasGo() error {
 // NeedsGo skips t if the current system does not have 'go'  or
 // cannot run them with exec.Command.
 func NeedsGo(t testing.TB) {
-	if err := hasGo(); err != nil {
+	if err := HasGo(); err != nil {
 		t.Skipf("skipping test: go is not available - %v", err)
 	}
 }