Fix toolrelay.exe's mt.exe detection: it never matched a real path

IsMtExe() looked for the last '\\' in the target executable path to
find the bare filename, but vintner passes toolExePath straight from
Go's filepath.Join (forward slashes) all the way through to
CreateProcessW - so the path toolrelay.exe actually receives has no
backslash in it at all, and IsMtExe() compared the *entire path*
against "mt.exe", which of course never matched. The whole point of
this file - translating mt.exe's CMake-compatibility exit code
(0x41020001 -> 0xbb) before Wine's own exit-code truncation destroys
it - has silently never fired in real usage.

This had gone unnoticed because MSBuild's rawStdout path bypasses
toolrelay.exe entirely, and every real end-to-end test so far
(msbuild-driven builds, including the KMDF driver) went through that
path. Found while getting a CMake+Ninja-generated MSVC build of a
real project (Ogre3D) past its `cmake -E vs_link_exe` manifest step,
which depends on exactly this translation.

Now checks for both '\\' and '/' and uses whichever separator occurs
last in the path. Verified directly: `mt /manifest ... /notify_update`
through the wrapper now exits 187 (0xbb) instead of 1, and the Ogre
build gets past the manifest-embedding step it was failing at.

internal/download/extract_test.go

@@ -0,0 +1,152 @@
+package download
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func writeFile(t *testing.T, path, content string) {
+	t.Helper()
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestCombineDirTreesNonexistentSrcIsNoop(t *testing.T) {
+	dest := t.TempDir()
+	if err := combineDirTrees(filepath.Join(t.TempDir(), "does-not-exist"), dest); err != nil {
+		t.Fatalf("combineDirTrees with a nonexistent src returned an error: %v", err)
+	}
+}
+
+func TestCombineDirTreesRenamesWholesaleWhenDestMissing(t *testing.T) {
+	root := t.TempDir()
+	src := filepath.Join(root, "src")
+	dest := filepath.Join(root, "nested", "dest")
+	writeFile(t, filepath.Join(src, "file.txt"), "hello")
+
+	if err := combineDirTrees(src, dest); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.ReadFile(filepath.Join(dest, "file.txt")); err != nil {
+		t.Errorf("expected %s/file.txt to exist after combine: %v", dest, err)
+	}
+	if isDir(src) {
+		t.Error("src should have been moved (renamed), not copied")
+	}
+}
+
+func TestCombineDirTreesMergesNewSubdir(t *testing.T) {
+	root := t.TempDir()
+	src, dest := filepath.Join(root, "src"), filepath.Join(root, "dest")
+	writeFile(t, filepath.Join(src, "NewDir", "a.txt"), "a")
+	writeFile(t, filepath.Join(dest, "Existing.txt"), "keep me")
+
+	if err := combineDirTrees(src, dest); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.ReadFile(filepath.Join(dest, "NewDir", "a.txt")); err != nil {
+		t.Errorf("expected merged NewDir/a.txt: %v", err)
+	}
+	if _, err := os.ReadFile(filepath.Join(dest, "Existing.txt")); err != nil {
+		t.Errorf("pre-existing dest file was lost: %v", err)
+	}
+}
+
+func TestCombineDirTreesMergesCaseInsensitiveCollision(t *testing.T) {
+	root := t.TempDir()
+	src, dest := filepath.Join(root, "src"), filepath.Join(root, "dest")
+	// src has "Include" (capital I), dest already has "include" (lowercase) -
+	// this is exactly the MSVC/WinSDK casing-inconsistency scenario the
+	// function's doc comment describes.
+	writeFile(t, filepath.Join(src, "Include", "new.h"), "new")
+	writeFile(t, filepath.Join(dest, "include", "old.h"), "old")
+
+	if err := combineDirTrees(src, dest); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.ReadFile(filepath.Join(dest, "include", "new.h")); err != nil {
+		t.Errorf("new.h should have merged into the existing lowercase 'include' dir: %v", err)
+	}
+	if _, err := os.ReadFile(filepath.Join(dest, "include", "old.h")); err != nil {
+		t.Errorf("old.h should still be there: %v", err)
+	}
+	if isDir(filepath.Join(dest, "Include")) {
+		t.Error("a separate capital-I 'Include' dir should not have been created")
+	}
+}
+
+func TestCombineDirTreesRecursesIntoExactNameMatch(t *testing.T) {
+	root := t.TempDir()
+	src, dest := filepath.Join(root, "src"), filepath.Join(root, "dest")
+	writeFile(t, filepath.Join(src, "lib", "x64", "new.lib"), "new")
+	writeFile(t, filepath.Join(dest, "lib", "x64", "old.lib"), "old")
+
+	if err := combineDirTrees(src, dest); err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range []string{"new.lib", "old.lib"} {
+		if _, err := os.ReadFile(filepath.Join(dest, "lib", "x64", f)); err != nil {
+			t.Errorf("expected lib/x64/%s to survive the merge: %v", f, err)
+		}
+	}
+}
+
+func TestCopyRedirectedAssembliesNoConfigIsNoop(t *testing.T) {
+	dir := t.TempDir()
+	app := filepath.Join(dir, "MSBuild.exe")
+	if err := CopyRedirectedAssemblies(app); err != nil {
+		t.Fatalf("with no .config file present, expected no error, got: %v", err)
+	}
+}
+
+func TestCopyRedirectedAssembliesCopiesReferencedDLL(t *testing.T) {
+	dir := t.TempDir()
+	app := filepath.Join(dir, "MSBuild.exe")
+	writeFile(t, app+".config", `<?xml version="1.0"?>
+<configuration>
+  <runtime>
+    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
+      <dependentAssembly>
+        <codeBase version="1.0.0.0" href="amd64\Some.Assembly.dll"/>
+      </dependentAssembly>
+    </assemblyBinding>
+  </runtime>
+</configuration>`)
+	writeFile(t, filepath.Join(dir, "amd64", "Some.Assembly.dll"), "binary-content")
+
+	if err := CopyRedirectedAssemblies(app); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := os.ReadFile(filepath.Join(dir, "Some.Assembly.dll"))
+	if err != nil {
+		t.Fatalf("expected Some.Assembly.dll copied next to MSBuild.exe: %v", err)
+	}
+	if string(got) != "binary-content" {
+		t.Errorf("copied file content = %q, want %q", got, "binary-content")
+	}
+}
+
+func TestCopyRedirectedAssembliesSkipsMissingTarget(t *testing.T) {
+	dir := t.TempDir()
+	app := filepath.Join(dir, "MSBuild.exe")
+	writeFile(t, app+".config", `<?xml version="1.0"?>
+<configuration>
+  <runtime>
+    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
+      <dependentAssembly>
+        <codeBase href="nowhere\Missing.dll"/>
+      </dependentAssembly>
+    </assemblyBinding>
+  </runtime>
+</configuration>`)
+
+	if err := CopyRedirectedAssemblies(app); err != nil {
+		t.Fatalf("a redirect pointing at a nonexistent file should be silently skipped, got: %v", err)
+	}
+}

internal/download/fetch_test.go

@@ -0,0 +1,59 @@
+package download
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestRetryBackoff(t *testing.T) {
+	for _, tc := range []struct {
+		attempt int
+		want    time.Duration
+	}{
+		{1, 1 * time.Second},
+		{2, 2 * time.Second},
+		{3, 4 * time.Second},
+		{4, 8 * time.Second},
+		{5, 10 * time.Second}, // capped
+		{10, 10 * time.Second},
+	} {
+		if got := retryBackoff(tc.attempt); got != tc.want {
+			t.Errorf("retryBackoff(%d) = %v, want %v", tc.attempt, got, tc.want)
+		}
+	}
+}
+
+func TestSHA256File(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "f")
+	if err := os.WriteFile(path, []byte("hello"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	got, err := sha256File(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// echo -n hello | sha256sum
+	want := "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
+	if got != want {
+		t.Errorf("sha256File(hello) = %q, want %q", got, want)
+	}
+}
+
+func TestEqualFoldHex(t *testing.T) {
+	for _, tc := range []struct {
+		a, b string
+		want bool
+	}{
+		{"ABCDEF", "abcdef", true},
+		{"abc123", "ABC123", true},
+		{"abc123", "abc124", false},
+		{"abc", "abcd", false},
+		{"", "", true},
+	} {
+		if got := equalFoldHex(tc.a, tc.b); got != tc.want {
+			t.Errorf("equalFoldHex(%q, %q) = %v, want %v", tc.a, tc.b, got, tc.want)
+		}
+	}
+}

internal/download/manifest_test.go

@@ -0,0 +1,134 @@
+package download
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestPayloadName(t *testing.T) {
+	for _, tc := range []struct {
+		fileName string
+		want     string
+	}{
+		{"payload.msi", "payload.msi"},
+		{"folder/payload.msi", "payload.msi"},
+		{`folder\payload.msi`, "payload.msi"},
+		{`a\b/c\payload.msi`, "payload.msi"},
+		{"", ""},
+	} {
+		p := Payload{FileName: tc.fileName}
+		if got := p.Name(); got != tc.want {
+			t.Errorf("Payload{FileName: %q}.Name() = %q, want %q", tc.fileName, got, tc.want)
+		}
+	}
+}
+
+func TestPackageKey(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		p    Package
+		want string
+	}{
+		{"id only", Package{ID: "Foo"}, "Foo"},
+		{"id+version", Package{ID: "Foo", Version: "1.0"}, "Foo-1.0"},
+		{
+			"id+version+all arches",
+			Package{ID: "Foo", Version: "1.0", Chip: "x64", MachineArch: "x86", ProductArch: "neutral"},
+			"Foo-1.0-chip.x64-machineArch.x86-productArch.neutral",
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := tc.p.Key(); got != tc.want {
+				t.Errorf("Key() = %q, want %q", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestPackageLocalized(t *testing.T) {
+	noResources := Package{}
+	if got := noResources.Localized("en"); got != nil {
+		t.Errorf("Localized() on a package with no LocalizedResources = %v, want nil", got)
+	}
+
+	p := Package{LocalizedResources: []LocalizedResource{
+		{Language: "de-DE", Title: "Deutsch"},
+		{Language: "en-US", Title: "English"},
+		{Language: "ru-RU", Title: "Русский"},
+	}}
+
+	for _, tc := range []struct {
+		lang      string
+		wantTitle string
+	}{
+		{"ru", "Русский"},
+		{"ru-RU", "Русский"},
+		{"en", "English"},
+		{"", "English"},   // "" defaults to "en"
+		{"fr", "English"}, // no fr variant, falls back to the en-* one
+	} {
+		t.Run("lang="+tc.lang, func(t *testing.T) {
+			got := p.Localized(tc.lang)
+			if got == nil {
+				t.Fatalf("Localized(%q) = nil", tc.lang)
+			}
+			if got.Title != tc.wantTitle {
+				t.Errorf("Localized(%q).Title = %q, want %q", tc.lang, got.Title, tc.wantTitle)
+			}
+		})
+	}
+}
+
+func TestPackageSizes(t *testing.T) {
+	p := Package{
+		InstallSizes: map[string]int64{"x86": 100, "x64": 200},
+		Payloads:     []Payload{{Size: 10}, {Size: 20}, {Size: 30}},
+	}
+	if got := p.InstalledSize(); got != 300 {
+		t.Errorf("InstalledSize() = %d, want 300", got)
+	}
+	if got := p.DownloadSize(); got != 60 {
+		t.Errorf("DownloadSize() = %d, want 60", got)
+	}
+}
+
+func TestPackageDependenciesNormalizesBothShapes(t *testing.T) {
+	p := Package{DependenciesRaw: map[string]json.RawMessage{
+		"Bare.Version":    json.RawMessage(`"1.0"`),
+		"Full.Object":     json.RawMessage(`{"version":"2.0","type":"Optional","id":"Real.Target"}`),
+		"Recommended.Dep": json.RawMessage(`{"version":"3.0","type":"Recommended"}`),
+	}}
+	deps := p.Dependencies()
+
+	if d := deps["Bare.Version"]; d.Version != "1.0" || d.TargetID != "" || d.Type != "" {
+		t.Errorf("Bare.Version = %+v, want Version=1.0 TargetID='' Type=''", d)
+	}
+	if d := deps["Full.Object"]; d.Version != "2.0" || d.TargetID != "Real.Target" || d.Type != "Optional" {
+		t.Errorf("Full.Object = %+v, want Version=2.0 TargetID=Real.Target Type=Optional", d)
+	}
+	if d := deps["Recommended.Dep"]; d.Version != "3.0" || d.Type != "Recommended" {
+		t.Errorf("Recommended.Dep = %+v, want Version=3.0 Type=Recommended", d)
+	}
+
+	// Calling Dependencies() again must return the same cached map, not
+	// re-parse (and must not panic on the second call).
+	if d2 := p.Dependencies(); len(d2) != len(deps) {
+		t.Errorf("second Dependencies() call returned a different map: %v vs %v", d2, deps)
+	}
+}
+
+func TestHumanizeBytes(t *testing.T) {
+	for _, tc := range []struct {
+		size int64
+		want string
+	}{
+		{500, "500 bytes"},
+		{2048, "2.0 KB"},
+		{5 * 1024 * 1024, "5.0 MB"},
+		{2 * 1024 * 1024 * 1024, "2.0 GB"},
+	} {
+		if got := HumanizeBytes(tc.size); got != tc.want {
+			t.Errorf("HumanizeBytes(%d) = %q, want %q", tc.size, got, tc.want)
+		}
+	}
+}

internal/download/wdk_test.go

@@ -0,0 +1,118 @@
+package download
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestWDKNuGetID(t *testing.T) {
+	for _, tc := range []struct{ arch, want string }{
+		{"x64", "Microsoft.Windows.WDK.x64"},
+		{"x86", "Microsoft.Windows.WDK.x64"}, // no 32-bit package exists
+		{"arm64", "Microsoft.Windows.WDK.ARM64"},
+	} {
+		if got := WDKNuGetID(tc.arch); got != tc.want {
+			t.Errorf("WDKNuGetID(%q) = %q, want %q", tc.arch, got, tc.want)
+		}
+	}
+}
+
+func TestSDKBuildPrefix(t *testing.T) {
+	for _, tc := range []struct {
+		name     string
+		selected []*Package
+		want     string
+	}{
+		{"no SDK package", []*Package{{ID: "Something.Else"}}, ""},
+		{"win10sdk", []*Package{{ID: "Win10SDK_10.0.26100", Version: "10.0.26100.1742"}}, "10.0.26100"},
+		{"win11sdk case-insensitive id", []*Package{{ID: "WIN11SDK_10.0.22621", Version: "10.0.22621.5"}}, "10.0.22621"},
+		{"short version", []*Package{{ID: "Win10SDK_x", Version: "10.0"}}, ""},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := SDKBuildPrefix(tc.selected); got != tc.want {
+				t.Errorf("SDKBuildPrefix(...) = %q, want %q", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestFillMissingHostToolsCopiesWithoutOverwriting(t *testing.T) {
+	cDir := t.TempDir()
+	writeFile(t, filepath.Join(cDir, "bin", "10.0.26100.0", "x64", "stampinf.exe"), "x64-stampinf")
+	writeFile(t, filepath.Join(cDir, "bin", "10.0.26100.0", "x64", "inf2cat.exe"), "x64-inf2cat")
+	// x86 already ships its own real inf2cat.exe - must not be clobbered.
+	writeFile(t, filepath.Join(cDir, "bin", "10.0.26100.0", "x86", "inf2cat.exe"), "real-x86-inf2cat")
+
+	if err := fillMissingHostTools(cDir); err != nil {
+		t.Fatal(err)
+	}
+
+	x86Dir := filepath.Join(cDir, "bin", "10.0.26100.0", "x86")
+	stampinf, err := os.ReadFile(filepath.Join(x86Dir, "stampinf.exe"))
+	if err != nil {
+		t.Fatalf("expected stampinf.exe to be copied into x86: %v", err)
+	}
+	if string(stampinf) != "x64-stampinf" {
+		t.Errorf("copied stampinf.exe content = %q, want the x64 copy's content", stampinf)
+	}
+
+	inf2cat, err := os.ReadFile(filepath.Join(x86Dir, "inf2cat.exe"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(inf2cat) != "real-x86-inf2cat" {
+		t.Errorf("inf2cat.exe = %q, want the original x86 file preserved (not overwritten by the x64 copy)", inf2cat)
+	}
+}
+
+func TestFillMissingHostToolsNoBinDirIsNoop(t *testing.T) {
+	if err := fillMissingHostTools(t.TempDir()); err != nil {
+		t.Fatalf("missing bin/ dir should be a no-op, got: %v", err)
+	}
+}
+
+func TestDuplicateVersionedBuildTaskAssemblies(t *testing.T) {
+	cDir := t.TempDir()
+	buildDir := filepath.Join(cDir, "build")
+	writeFile(t, filepath.Join(buildDir, "Microsoft.DriverKit.Build.Tasks.17.0.dll"), "task-dll-bytes")
+	writeFile(t, filepath.Join(buildDir, "Microsoft.DriverKit.Build.Tasks.18.0.dll"), "already-there")
+	writeFile(t, filepath.Join(buildDir, "unrelated.dll"), "unrelated")
+
+	if err := duplicateVersionedBuildTaskAssemblies(cDir, "18.0"); err != nil {
+		t.Fatal(err)
+	}
+
+	// Already had an 18.0 copy - must not have been overwritten.
+	got, err := os.ReadFile(filepath.Join(buildDir, "Microsoft.DriverKit.Build.Tasks.18.0.dll"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != "already-there" {
+		t.Errorf("pre-existing 18.0 dll was overwritten: got %q", got)
+	}
+}
+
+func TestDuplicateVersionedBuildTaskAssembliesCreatesMissingCopy(t *testing.T) {
+	cDir := t.TempDir()
+	buildDir := filepath.Join(cDir, "build")
+	writeFile(t, filepath.Join(buildDir, "sub", "Foo.Bar.17.0.dll"), "bytes")
+
+	if err := duplicateVersionedBuildTaskAssemblies(cDir, "18.0"); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := os.ReadFile(filepath.Join(buildDir, "sub", "Foo.Bar.18.0.dll"))
+	if err != nil {
+		t.Fatalf("expected a Foo.Bar.18.0.dll duplicate: %v", err)
+	}
+	if string(got) != "bytes" {
+		t.Errorf("duplicated dll content = %q, want %q", got, "bytes")
+	}
+}
+
+func TestDuplicateVersionedBuildTaskAssembliesNoBuildDirIsNoop(t *testing.T) {
+	if err := duplicateVersionedBuildTaskAssemblies(t.TempDir(), "18.0"); err != nil {
+		t.Fatalf("missing build/ dir should be a no-op, got: %v", err)
+	}
+}

internal/wrapper/clpost_test.go

@@ -0,0 +1,61 @@
+package wrapper
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestClPostProcessRewritesLineDirectivesInPreprocessedOutput(t *testing.T) {
+	dir := t.TempDir()
+	fi := filepath.Join(dir, "out.i")
+	// A #line directive as cl.exe's /P emits it: z:-prefixed, backslash
+	// path, doubled ("escaped") backslashes, CRLF line ending.
+	input := "#line 1 \"z:\\\\home\\\\user\\\\src\\\\hello.c\"\r\n" +
+		"int main(void) { return 0; }\r\n"
+	if err := os.WriteFile(fi, []byte(input), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	clPostProcess([]string{"/P", "/Fi" + fi, "hello.c"})
+
+	got, err := os.ReadFile(fi)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := "#line 1 \"/home/user/src/hello.c\"\n" +
+		"int main(void) { return 0; }\n"
+	if string(got) != want {
+		t.Errorf("clPostProcess output = %q, want %q", got, want)
+	}
+}
+
+func TestClPostProcessNoopWithoutP(t *testing.T) {
+	dir := t.TempDir()
+	fi := filepath.Join(dir, "out.i")
+	original := "#line 1 \"z:\\\\foo.c\"\r\n"
+	if err := os.WriteFile(fi, []byte(original), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	// No "/P" flag - should leave the file untouched even though -Fi is present.
+	clPostProcess([]string{"/Fi" + fi, "foo.c"})
+
+	got, err := os.ReadFile(fi)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != original {
+		t.Errorf("file was modified without /P: got %q, want unchanged %q", got, original)
+	}
+}
+
+func TestClPostProcessNoopWithoutFi(t *testing.T) {
+	// Must not panic or error when -Fi wasn't passed - just silently skip.
+	clPostProcess([]string{"/P", "foo.c"})
+}
+
+func TestClPostProcessMissingFileIsSilent(t *testing.T) {
+	// The referenced -Fi file doesn't exist - clPostProcess must not panic.
+	clPostProcess([]string{"/P", "/Fi" + filepath.Join(t.TempDir(), "missing.i"), "foo.c"})
+}

internal/wrapper/msbuildenv_test.go

@@ -0,0 +1,117 @@
+package wrapper
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/Cheviiot/vintner/internal/wineenv"
+)
+
+func TestMsbuildPlatform(t *testing.T) {
+	for _, tc := range []struct{ arch, want string }{
+		{"x86", "Win32"},
+		{"x64", "x64"},
+		{"arm", "ARM"},
+		{"arm64", "ARM64"},
+	} {
+		if got := msbuildPlatform(tc.arch); got != tc.want {
+			t.Errorf("msbuildPlatform(%q) = %q, want %q", tc.arch, got, tc.want)
+		}
+	}
+}
+
+func newTestPaths(t *testing.T, cfg *wineenv.Config) (*wineenv.Paths, string) {
+	t.Helper()
+	base := t.TempDir()
+	return wineenv.NewPaths(cfg, base), base
+}
+
+func TestMsbuildEnvBasics(t *testing.T) {
+	cfg := &wineenv.Config{Arch: "x64", Host: "x64", DotnetHost: "amd64", MSVCVer: "14.51.36231", SDKVer: "10.0.26100.0"}
+	paths, _ := newTestPaths(t, cfg)
+
+	env := msbuildEnv(cfg, paths)
+
+	if env["TZ"] != "UTC" {
+		t.Errorf(`env["TZ"] = %q, want "UTC"`, env["TZ"])
+	}
+	if env["DisableRegistryUse"] != "true" {
+		t.Errorf(`env["DisableRegistryUse"] = %q, want "true"`, env["DisableRegistryUse"])
+	}
+	if env["VCToolsVersion"] != cfg.MSVCVer {
+		t.Errorf(`env["VCToolsVersion"] = %q, want %q`, env["VCToolsVersion"], cfg.MSVCVer)
+	}
+	if env["WindowsTargetPlatformVersion"] != cfg.SDKVer {
+		t.Errorf(`env["WindowsTargetPlatformVersion"] = %q, want %q`, env["WindowsTargetPlatformVersion"], cfg.SDKVer)
+	}
+	if env["Platform"] != "x64" {
+		t.Errorf(`env["Platform"] = %q, want "x64"`, env["Platform"])
+	}
+	if env["SignMode"] != "off" {
+		t.Errorf(`env["SignMode"] = %q, want "off" (driver builds must not attempt real signing)`, env["SignMode"])
+	}
+	// No WDK content on disk in this test - must not claim otherwise.
+	if _, ok := env["WDKContentRoot"]; ok {
+		t.Error(`env["WDKContentRoot"] set even though no wdk/<arch>/c directory exists`)
+	}
+}
+
+func TestMsbuildEnvDiscoversEveryToolsetVersion(t *testing.T) {
+	cfg := &wineenv.Config{Arch: "x64", Host: "x64", DotnetHost: "amd64", MSVCVer: "14.51.36231", SDKVer: "10.0.26100.0"}
+	paths, base := newTestPaths(t, cfg)
+
+	for _, v := range []string{"v145", "v180", "not-a-version"} {
+		if err := os.MkdirAll(filepath.Join(base, "MSBuild", "Microsoft", "VC", v), 0o755); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	env := msbuildEnv(cfg, paths)
+
+	for _, n := range []string{"145", "180"} {
+		if _, ok := env["VCInstallDir_"+n]; !ok {
+			t.Errorf("expected VCInstallDir_%s to be set", n)
+		}
+		if _, ok := env["VCToolsInstallDir_"+n]; !ok {
+			t.Errorf("expected VCToolsInstallDir_%s to be set", n)
+		}
+	}
+	if _, ok := env["VCInstallDir_not-a-version"]; ok {
+		t.Error("a directory not matching v<digits> should not have produced a VCInstallDir_ entry")
+	}
+}
+
+func TestMsbuildEnvDetectsWDKContentRoot(t *testing.T) {
+	cfg := &wineenv.Config{Arch: "x64", Host: "x64", DotnetHost: "amd64", MSVCVer: "14.51.36231", SDKVer: "10.0.26100.0"}
+	paths, base := newTestPaths(t, cfg)
+
+	if err := os.MkdirAll(filepath.Join(base, "wdk", "x64", "c"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	env := msbuildEnv(cfg, paths)
+
+	if env["WDKContentRoot"] == "" {
+		t.Error("expected WDKContentRoot to be set once wdk/x64/c exists on disk")
+	}
+	if env["WDKBuildFolder"] != cfg.SDKVer {
+		t.Errorf(`env["WDKBuildFolder"] = %q, want %q`, env["WDKBuildFolder"], cfg.SDKVer)
+	}
+}
+
+func TestMsbuildEnvPreferredToolArchitecture(t *testing.T) {
+	// PreferredToolArchitecture should only be set when the host toolset
+	// bin dir is the 64-bit ("amd64") .NET host - not for arm64.
+	cfg64 := &wineenv.Config{Arch: "x64", Host: "x64", DotnetHost: "amd64", MSVCVer: "1", SDKVer: "1"}
+	paths64, _ := newTestPaths(t, cfg64)
+	if env := msbuildEnv(cfg64, paths64); env["PreferredToolArchitecture"] != "x64" {
+		t.Errorf(`with DotnetHost=amd64, PreferredToolArchitecture = %q, want "x64"`, env["PreferredToolArchitecture"])
+	}
+
+	cfgARM := &wineenv.Config{Arch: "arm64", Host: "arm64", DotnetHost: "arm64", MSVCVer: "1", SDKVer: "1"}
+	pathsARM, _ := newTestPaths(t, cfgARM)
+	if env := msbuildEnv(cfgARM, pathsARM); env["PreferredToolArchitecture"] != "" {
+		t.Errorf(`with DotnetHost=arm64, PreferredToolArchitecture = %q, want unset`, env["PreferredToolArchitecture"])
+	}
+}

internal/wrapper/tools_test.go

@@ -0,0 +1,45 @@
+package wrapper
+
+import (
+	"testing"
+
+	"github.com/Cheviiot/vintner/internal/wineenv"
+)
+
+func TestSpecExeDir(t *testing.T) {
+	paths := &wineenv.Paths{
+		BinDir:        "/bin-dir",
+		SDKBinDir:     "/sdk-bin-dir",
+		MSBuildBinDir: "/msbuild-bin-dir",
+	}
+	for _, tc := range []struct {
+		name string
+		dir  dirKind
+		want string
+	}{
+		{"dirBin", dirBin, "/bin-dir"},
+		{"dirSDK", dirSDK, "/sdk-bin-dir"},
+		{"dirMSBuild", dirMSBuild, "/msbuild-bin-dir"},
+	} {
+		s := spec{dir: tc.dir}
+		if got := s.exeDir(paths); got != tc.want {
+			t.Errorf("%s: exeDir() = %q, want %q", tc.name, got, tc.want)
+		}
+	}
+}
+
+func TestToolsAndNativeToolsAreDisjoint(t *testing.T) {
+	for name := range Tools {
+		if nativeTools[name] {
+			t.Errorf("%q is in both Tools and nativeTools", name)
+		}
+	}
+}
+
+func TestEveryToolHasAnExeName(t *testing.T) {
+	for name, s := range Tools {
+		if s.exeName == "" {
+			t.Errorf("Tools[%q] has no exeName", name)
+		}
+	}
+}