Consolidate artifact declarations

internal/artifact/artifact.go

@@ -0,0 +1,62 @@
+// Package artifact owns shared build artifact identity rules.
+package artifact
+
+import (
+	"fmt"
+	"strings"
+)
+
+const ManifestFilename = "SHA256SUMS"
+
+type Target struct {
+	OS   string
+	Arch string
+}
+
+type Declaration struct {
+	Target   Target
+	Filename string
+}
+
+// NormalizeTargets removes duplicate targets while preserving their first
+// occurrence.
+func NormalizeTargets(targets []Target) []Target {
+	seen := make(map[Target]struct{}, len(targets))
+	result := make([]Target, 0, len(targets))
+	for _, target := range targets {
+		if _, ok := seen[target]; ok {
+			continue
+		}
+		seen[target] = struct{}{}
+		result = append(result, target)
+	}
+	return result
+}
+
+// ValidComponent reports whether value is a nonempty filename component under
+// the build and receipt contracts.
+func ValidComponent(value string) bool {
+	return value != "" && !strings.ContainsAny(value, "/\\\r\n")
+}
+
+// Filename returns the declared binary filename for one target.
+func Filename(binaryName, version string, target Target) string {
+	filename := fmt.Sprintf("%s-%s-%s-%s", binaryName, version, target.OS, target.Arch)
+	if target.OS == "windows" {
+		filename += ".exe"
+	}
+	return filename
+}
+
+// ExpectedBuild returns artifact declarations in target order. Callers retain
+// responsibility for validating their boundary-specific build identity.
+func ExpectedBuild(binaryName, version string, targets []Target) []Declaration {
+	declarations := make([]Declaration, 0, len(targets))
+	for _, target := range targets {
+		declarations = append(declarations, Declaration{
+			Target:   target,
+			Filename: Filename(binaryName, version, target),
+		})
+	}
+	return declarations
+}

internal/artifact/artifact_test.go

@@ -0,0 +1,42 @@
+package artifact
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestNormalizeTargetsPreservesOrderAndFirstOccurrence(t *testing.T) {
+	targets := []Target{
+		{OS: "linux", Arch: "amd64"},
+		{OS: "windows", Arch: "arm64"},
+		{OS: "linux", Arch: "amd64"},
+	}
+	want := []Target{{OS: "linux", Arch: "amd64"}, {OS: "windows", Arch: "arm64"}}
+	if got := NormalizeTargets(targets); !reflect.DeepEqual(got, want) {
+		t.Fatalf("NormalizeTargets() = %#v, want %#v", got, want)
+	}
+}
+
+func TestExpectedBuildUsesSharedNamesInTargetOrder(t *testing.T) {
+	targets := []Target{{OS: "windows", Arch: "arm64"}, {OS: "linux", Arch: "amd64"}}
+	want := []Declaration{
+		{Target: targets[0], Filename: "app-v1.2.3-windows-arm64.exe"},
+		{Target: targets[1], Filename: "app-v1.2.3-linux-amd64"},
+	}
+	if got := ExpectedBuild("app", "v1.2.3", targets); !reflect.DeepEqual(got, want) {
+		t.Fatalf("ExpectedBuild() = %#v, want %#v", got, want)
+	}
+}
+
+func TestValidComponentPreservesBuildAndReceiptRules(t *testing.T) {
+	for _, value := range []string{"", "path/name", `path\name`, "line\nbreak", "line\rbreak"} {
+		if ValidComponent(value) {
+			t.Errorf("ValidComponent(%q) = true, want false", value)
+		}
+	}
+	for _, value := range []string{"app", "..", "nul\x00byte"} {
+		if !ValidComponent(value) {
+			t.Errorf("ValidComponent(%q) = false, want true", value)
+		}
+	}
+}