test(ci): cover canonical skill platform branches

internal/app/skill_command_test.go

@@ -122,6 +122,9 @@ func TestResolveSkillTargetPath(t *testing.T) {
 func TestCrossPlatformCoverageUniversalSkillInstallTargetsUseCanonical(t *testing.T) {
 	home := t.TempDir()
 	testseam.Swap(t, &skillUserHomeDir, func() (string, error) { return home, nil })
+	if isUniversalSkillInstallTarget("missing-agent") {
+		t.Fatal("unknown Agent target classified as universal")
+	}
 	for _, target := range []string{
 		"amp", "antigravity", "antigravity-cli", "cline", "codex", "cursor",
 		"deepagents", "dexto", "firebender", "gemini", "gemini-cli", "github",

internal/app/skill_setup.go

@@ -1121,9 +1121,6 @@ func detectExistingAgentHomes(home, mode string) []string {
 				return
 			}
 		}
-		if base == "" {
-			return
-		}
 		dest := agentHomeForMode(base, mode)
 		key := skillSetupPathKey(dest)
 		if !seen[key] {

internal/app/skill_setup_canonical_test.go

@@ -103,6 +103,7 @@ func TestCrossPlatformCoverageSkillSetupCanonicalTargetsAndAgentCapabilities(t *
 func TestCrossPlatformCoverageSkillSetupDetectsShallowAndApplicationAgents(t *testing.T) {
 	home := t.TempDir()
 	testseam.Swap(t, &skillSetupSystemHomeDir, func() (string, error) { return home, nil })
+	testseam.Swap(t, &skillSetupGetenv, func(string) string { return "" })
 	for _, dir := range []string{filepath.Join(home, ".config", "kimchi"), filepath.Join(home, ".tabnine")} {
 		if err := os.MkdirAll(dir, 0o755); err != nil {
 			t.Fatal(err)
@@ -116,9 +117,11 @@ func TestCrossPlatformCoverageSkillSetupDetectsShallowAndApplicationAgents(t *te
 	if err != nil {
 		t.Fatal(err)
 	}
+	zcodeApp := filepath.Join(string(filepath.Separator), "Applications", "ZCode.app")
+	minimaxApp := filepath.Join(string(filepath.Separator), "Applications", "MiniMax Code.app")
 	originalStat := skillSetupStat
 	testseam.Swap(t, &skillSetupStat, func(path string) (os.FileInfo, error) {
-		if path == "/Applications/ZCode.app" || path == "/Applications/MiniMax Code.app" {
+		if path == zcodeApp || path == minimaxApp {
 			return appInfo, nil
 		}
 		return originalStat(path)

internal/app/skill_setup_event_migration_universal_test.go

@@ -1,6 +1,8 @@
 package app
 
 import (
+	"errors"
+	"io"
 	"os"
 	"path/filepath"
 	"strings"
@@ -85,3 +87,48 @@ func TestCrossPlatformCoverageSkillSetupUnrelatedSelectionPreservesUniversalFold
 		t.Fatalf("unselected chat changed: body=%q err=%v", body, err)
 	}
 }
+
+func TestCrossPlatformCoverageSkillSetupUniversalRetirementFailures(t *testing.T) {
+	failure := errors.New("retirement denied")
+
+	t.Run("home", func(t *testing.T) {
+		testseam.Swap(t, &skillSetupUserHomeDir, func() (string, error) { return "", failure })
+		codex := filepath.Join(t.TempDir(), ".codex", "skills")
+		if err := retireMigratedUniversalSkills([]string{codex}, []string{multiEventSkill}, io.Discard); !errors.Is(err, failure) {
+			t.Fatalf("home failure = %v, want %v", err, failure)
+		}
+	})
+
+	t.Run("deduplicate", func(t *testing.T) {
+		home := t.TempDir()
+		testseam.Swap(t, &skillSetupUserHomeDir, func() (string, error) { return home, nil })
+		codex := filepath.Join(home, ".codex", "skills")
+		if err := retireMigratedUniversalSkills(
+			[]string{codex, codex},
+			[]string{multiEventSkill, multiEventSkill},
+			io.Discard,
+		); err != nil {
+			t.Fatalf("deduplicated retirement failed: %v", err)
+		}
+	})
+
+	t.Run("backup propagates through command", func(t *testing.T) {
+		home := t.TempDir()
+		testseam.Swap(t, &skillSetupUserHomeDir, func() (string, error) { return home, nil })
+		codex := filepath.Join(home, ".codex", "skills")
+		writeFoldedEventMisc(t, codex)
+		src := writeMultiSkillSource(t, []string{multiEventSkill, multiSharedSkill, multiMiscSkill})
+		testseam.Swap(t, &skillSetupBackupAndRemove, func(string, string) (string, error) {
+			return "", failure
+		})
+		_, _, err := executeMultiSkillSetupTest(
+			t,
+			src,
+			[]string{filepath.Join(home, ".agents", "skills"), codex},
+			"--skill", "event", "--yes",
+		)
+		if !errors.Is(err, failure) || !strings.Contains(err.Error(), "退役 universal Agent") {
+			t.Fatalf("retirement backup failure = %v, want wrapped %v", err, failure)
+		}
+	})
+}

internal/app/skill_setup_full_coverage_test.go

@@ -537,6 +537,26 @@ func TestCrossPlatformCoverageSkillSetupEventMigrationFailureBranches(t *testing
 		}
 	})
 
+	t.Run("canonical ordinary install error", func(t *testing.T) {
+		testseam.Swap(t, &skillSetupInstallMulti, func(string, []string, []string, io.Writer, io.Writer, bool) (int, int, error) {
+			return 0, 0, fail
+		})
+		home := t.TempDir()
+		canonical := filepath.Join(home, ".agents", "skills")
+		universalMigration := filepath.Join(home, ".codex", "skills")
+		if _, _, err := installMultiSkillsWithEventMigration(
+			"src",
+			[]string{multiEventSkill},
+			[]string{canonical, universalMigration},
+			[]string{universalMigration},
+			true,
+			io.Discard,
+			io.Discard,
+		); !errors.Is(err, fail) {
+			t.Fatalf("canonical ordinary install failure = %v, want %v", err, fail)
+		}
+	})
+
 	t.Run("prerequisite install error", func(t *testing.T) {
 		testseam.Swap(t, &skillSetupInstallMulti, func(string, []string, []string, io.Writer, io.Writer, bool) (int, int, error) {
 			return 0, 0, fail

internal/upgrade/canonical_skills_test.go

@@ -164,6 +164,7 @@ func TestCrossPlatformCoverageCanonicalSkillLinksFallBackToCopies(t *testing.T)
 func TestCrossPlatformCoverageConfiguredRootsDetectShallowAndApplicationAgents(t *testing.T) {
 	home := t.TempDir()
 	testseam.Swap(t, &upgradeSystemHomeDir, func() (string, error) { return home, nil })
+	testseam.Swap(t, &upgradeGetenv, func(string) string { return "" })
 	for _, dir := range []string{filepath.Join(home, ".config", "kimchi"), filepath.Join(home, ".tabnine")} {
 		if err := os.MkdirAll(dir, 0o755); err != nil {
 			t.Fatal(err)
@@ -177,9 +178,11 @@ func TestCrossPlatformCoverageConfiguredRootsDetectShallowAndApplicationAgents(t
 	if err != nil {
 		t.Fatal(err)
 	}
+	zcodeApp := filepath.Join(string(filepath.Separator), "Applications", "ZCode.app")
+	minimaxApp := filepath.Join(string(filepath.Separator), "Applications", "MiniMax Code.app")
 	originalStat := upgradeStat
 	testseam.Swap(t, &upgradeStat, func(path string) (os.FileInfo, error) {
-		if path == "/Applications/ZCode.app" || path == "/Applications/MiniMax Code.app" {
+		if path == zcodeApp || path == minimaxApp {
 			return appInfo, nil
 		}
 		return originalStat(path)