tpl/internal: Sync go_templates

Closes #10411

tpl/internal/go_templates/testenv/testenv_test.go

@@ -0,0 +1,54 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testenv_test
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/gohugoio/hugo/tpl/internal/go_templates/testenv"
+)
+
+func _TestGoToolLocation(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
+	var exeSuffix string
+	if runtime.GOOS == "windows" {
+		exeSuffix = ".exe"
+	}
+
+	// Tests are defined to run within their package source directory,
+	// and this package's source directory is $GOROOT/src/internal/testenv.
+	// The 'go' command is installed at $GOROOT/bin/go, so if the environment
+	// is correct then testenv.GoTool() should be identical to ../../../bin/go.
+
+	relWant := "../../../bin/go" + exeSuffix
+	absWant, err := filepath.Abs(relWant)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wantInfo, err := os.Stat(absWant)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("found go tool at %q (%q)", relWant, absWant)
+
+	goTool, err := testenv.GoTool()
+	if err != nil {
+		t.Fatalf("testenv.GoTool(): %v", err)
+	}
+	t.Logf("testenv.GoTool() = %q", goTool)
+
+	gotInfo, err := os.Stat(goTool)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !os.SameFile(wantInfo, gotInfo) {
+		t.Fatalf("%q is not the same file as %q", absWant, goTool)
+	}
+}