Centralize Go validation and build environments

internal/candidate/check_test.go

@@ -90,6 +90,60 @@ func TestCheckRunsDefaultOfflineGoValidation(t *testing.T) {
 	}
 }
 
+func TestDefaultValidationDoesNotInheritGOFLAGSRunFilter(t *testing.T) {
+	repository := newRepository(t, "# Example Product v1.2.3\n\nRelease note.\n")
+	writeTestFile(t, repository, "failure_test.go", "package candidate\nimport \"testing\"\nfunc TestExpectedFailure(t *testing.T) { t.Fatal(\"expected fixture failure\") }\n")
+	gitRun(t, repository, "add", "failure_test.go")
+	gitRun(t, repository, "commit", "-m", "add failing validation fixture")
+
+	for _, source := range []string{"process environment", "Go environment file"} {
+		t.Run(source, func(t *testing.T) {
+			unsetCandidateEnv(t, "GOFLAGS", "GOOS", "GOARCH")
+			goEnv := filepath.Join(t.TempDir(), "go-env")
+			if source == "Go environment file" {
+				if err := os.WriteFile(goEnv, []byte("GOFLAGS=-run=^$\nGOOS=windows\nGOARCH=arm64\n"), 0o600); err != nil {
+					t.Fatal(err)
+				}
+			} else {
+				if err := os.WriteFile(goEnv, nil, 0o600); err != nil {
+					t.Fatal(err)
+				}
+				t.Setenv("GOFLAGS", "-run=^$")
+				t.Setenv("GOOS", "windows")
+				t.Setenv("GOARCH", "arm64")
+			}
+			t.Setenv("GOENV", goEnv)
+			var output bytes.Buffer
+			_, err := Check(context.Background(), Request{
+				RepositoryDir: repository,
+				Product:       "Example Product",
+				Version:       testVersion,
+				Output:        &output,
+			})
+			if err == nil || !strings.Contains(output.String(), "TestExpectedFailure") {
+				t.Fatalf("Check() error = %v, output = %q; wanted the failing standard test to run", err, output.String())
+			}
+		})
+	}
+}
+
+func unsetCandidateEnv(t *testing.T, keys ...string) {
+	t.Helper()
+	for _, key := range keys {
+		value, exists := os.LookupEnv(key)
+		if err := os.Unsetenv(key); err != nil {
+			t.Fatal(err)
+		}
+		t.Cleanup(func() {
+			if exists {
+				_ = os.Setenv(key, value)
+			} else {
+				_ = os.Unsetenv(key)
+			}
+		})
+	}
+}
+
 func TestCheckRejectsInvalidVersionsBeforeGitAccess(t *testing.T) {
 	for _, version := range []string{"v01.2.3", "v1.2.3-alpha", "1.2.3"} {
 		t.Run(version, func(t *testing.T) {