internal/cueversion: convert spaces to underscore in Go version

A Component/Version pair inside a User-Agent header
should not contain spaces, but `runtime.Version` can
return a version containing spaces when using a development
version (for example "devel go1.23-2ab9218c86 2024-03-11 22:10:38 +0000").

So convert spaces to underscores before putting that string
in the User-Agent header.

Signed-off-by: Roger Peppe <[email protected]>
Change-Id: I03e433429db80ccadf44983b4938fbdf14b08673
Dispatch-Trailer: {"type":"trybot","CL":1178179,"patchset":2,"ref":"refs/changes/79/1178179/2","targetBranch":"master"}

internal/cueversion/version.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"runtime"
 	"runtime/debug"
+	"strings"
 	"sync"
 )
 
@@ -51,5 +52,10 @@ func UserAgent(clientType string) string {
 	if clientType == "" {
 		clientType = "cuelang.org/go"
 	}
-	return fmt.Sprintf("Cue/%s (%s) Go/%s (%s/%s)", Version(), clientType, runtime.Version(), runtime.GOOS, runtime.GOARCH)
+	// The Go version can contain spaces, but we don't want spaces inside
+	// Component/Version pair, so replace them with underscores.
+	// As the runtime version won't contain underscores itself, this
+	// is reversible.
+	goVersion := strings.ReplaceAll(runtime.Version(), "_", " ")
+	return fmt.Sprintf("Cue/%s (%s) Go/%s (%s/%s)", Version(), clientType, goVersion, runtime.GOOS, runtime.GOARCH)
 }

internal/cueversion/version_test.go

@@ -24,7 +24,7 @@ func TestVersion(t *testing.T) {
 func TestUserAgent(t *testing.T) {
 	agent := UserAgent("custom")
 	qt.Assert(t, qt.Matches(agent,
-		`Cue/v[^ ]+ \(custom\) Go/go1\.[^ ]+ \([^/]+/[^/]+\)`,
+		`Cue/v[^ ]+ \(custom\) Go/[^ ]+ \([^/]+/[^/]+\)`,
 	))
 }