[core-be-agent] bundle: add bundle_helpers_test.go — 17 cases for pure helpers

Tests:
- splitLines: basic, trailing newline, empty, single char
- extractDescription: plain text, after frontmatter, skips comments,
  only comments, empty, frontmatter-only
- nilIfEmpty: empty→nil, non-empty→same
- buildBundleConfigFiles: system prompt, config.yaml prompts, skill files,
  combined, empty bundle
- findConfigDir: exact name match, fallback to first, no dirs→"",
  unreadable dir→""

No go binary in container — validated by CI.

workspace-server/internal/bundle/bundle_helpers_test.go

@@ -0,0 +1,243 @@
+package bundle
+
+// bundle_helpers_test.go — unit coverage for pure helper functions in the
+// bundle package (exporter.go, importer.go).
+//
+// Coverage targets:
+//   - splitLines: empty, no trailing newline, trailing newline,
+//     multiple newlines, single char
+//   - extractDescription: plain text, after frontmatter, after comments,
+//     only comments/whitespace, empty
+//   - nilIfEmpty: empty string → nil, non-empty → same string
+//   - buildBundleConfigFiles: system prompt only, config.yaml prompt,
+//     skill files, combined, empty bundle
+//   - findConfigDir: exact name match, fallback to first dir,
+//     no match returns fallback, unreadable dir returns ""
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// ---------- splitLines ----------
+
+func TestSplitLines_Basic(t *testing.T) {
+	got := splitLines("a\nb\nc")
+	want := []string{"a", "b", "c"}
+	if len(got) != len(want) {
+		t.Fatalf("len=%d; want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("got[%d]=%q; want %q", i, got[i], want[i])
+		}
+	}
+}
+
+func TestSplitLines_TrailingNewline(t *testing.T) {
+	got := splitLines("a\nb\n")
+	want := []string{"a", "b"}
+	if len(got) != len(want) {
+		t.Errorf("trailing newline should not produce extra empty string; got %v", got)
+	}
+}
+
+func TestSplitLines_Empty(t *testing.T) {
+	got := splitLines("")
+	want := []string{""}
+	if len(got) != len(want) {
+		t.Errorf("empty string should produce one empty-string element; got %v", got)
+	}
+}
+
+func TestSplitLines_SingleCharNoNewline(t *testing.T) {
+	got := splitLines("x")
+	want := []string{"x"}
+	if len(got) != 1 || got[0] != "x" {
+		t.Errorf("single char; got %v", got)
+	}
+}
+
+// ---------- extractDescription ----------
+
+func TestExtractDescription_PlainText(t *testing.T) {
+	got := extractDescription("This is the description\nAnother line")
+	if got != "This is the description" {
+		t.Errorf("got %q; want %q", got, "This is the description")
+	}
+}
+
+func TestExtractDescription_AfterFrontmatter(t *testing.T) {
+	content := `---
+title: Foo
+---
+This is the real description
+More detail here`
+	got := extractDescription(content)
+	if got != "This is the real description" {
+		t.Errorf("got %q; want %q", got, "This is the real description")
+	}
+}
+
+func TestExtractDescription_SkipsComments(t *testing.T) {
+	content := `# Comment line\n# Another comment\nDescription line\nExtra`
+	got := extractDescription(content)
+	if got != "Description line" {
+		t.Errorf("got %q; want %q", got, "Description line")
+	}
+}
+
+func TestExtractDescription_OnlyComments(t *testing.T) {
+	got := extractDescription("# Comment\n# Another")
+	if got != "" {
+		t.Errorf("only comments → want empty; got %q", got)
+	}
+}
+
+func TestExtractDescription_Empty(t *testing.T) {
+	got := extractDescription("")
+	if got != "" {
+		t.Errorf("empty → want empty; got %q", got)
+	}
+}
+
+func TestExtractDescription_FrontmatterOnly(t *testing.T) {
+	content := "---\nkey: value\n---"
+	got := extractDescription(content)
+	if got != "" {
+		t.Errorf("frontmatter only → want empty; got %q", got)
+	}
+}
+
+// ---------- nilIfEmpty ----------
+
+func TestNilIfEmpty_Empty(t *testing.T) {
+	got := nilIfEmpty("")
+	if got != nil {
+		t.Errorf("nilIfEmpty(\"\") = %v; want nil", got)
+	}
+}
+
+func TestNilIfEmpty_NonEmpty(t *testing.T) {
+	got := nilIfEmpty("hello")
+	if got != "hello" {
+		t.Errorf("nilIfEmpty(\"hello\") = %v; want \"hello\"", got)
+	}
+}
+
+// ---------- buildBundleConfigFiles ----------
+
+func TestBuildBundleConfigFiles_SystemPrompt(t *testing.T) {
+	b := &Bundle{SystemPrompt: "# System prompt content"}
+	files := buildBundleConfigFiles(b)
+	if v, ok := files["system-prompt.md"]; !ok {
+		t.Error("system-prompt.md missing")
+	} else if string(v) != "# System prompt content" {
+		t.Errorf("system-prompt.md = %q; want %q", v, "# System prompt content")
+	}
+}
+
+func TestBuildBundleConfigFiles_ConfigYaml(t *testing.T) {
+	b := &Bundle{Prompts: map[string]string{"config.yaml": "name: test\ntier: 1"}}
+	files := buildBundleConfigFiles(b)
+	if v, ok := files["config.yaml"]; !ok {
+		t.Error("config.yaml missing from prompts")
+	} else if string(v) != "name: test\ntier: 1" {
+		t.Errorf("config.yaml = %q; want %q", v, "name: test\ntier: 1")
+	}
+}
+
+func TestBuildBundleConfigFiles_SkillFiles(t *testing.T) {
+	b := &Bundle{
+		Skills: []BundleSkill{
+			{ID: "my-skill", Files: map[string]string{
+				"SKILL.md": "# My Skill",
+				"prompt.txt": "Do stuff",
+			}},
+		},
+	}
+	files := buildBundleConfigFiles(b)
+	if v, ok := files["skills/my-skill/SKILL.md"]; !ok {
+		t.Error("skills/my-skill/SKILL.md missing")
+	} else if string(v) != "# My Skill" {
+		t.Errorf("skills/my-skill/SKILL.md = %q; want %q", v, "# My Skill")
+	}
+	if v, ok := files["skills/my-skill/prompt.txt"]; !ok {
+		t.Error("skills/my-skill/prompt.txt missing")
+	} else if string(v) != "Do stuff" {
+		t.Errorf("skills/my-skill/prompt.txt = %q; want %q", v, "Do stuff")
+	}
+}
+
+func TestBuildBundleConfigFiles_Combined(t *testing.T) {
+	b := &Bundle{
+		SystemPrompt: "System",
+		Prompts:      map[string]string{"config.yaml": "cfg"},
+		Skills: []BundleSkill{
+			{ID: "s1", Files: map[string]string{"a.md": "A"}},
+		},
+	}
+	files := buildBundleConfigFiles(b)
+	if len(files) != 3 {
+		t.Errorf("got %d files; want 3", len(files))
+	}
+}
+
+func TestBuildBundleConfigFiles_Empty(t *testing.T) {
+	b := &Bundle{}
+	files := buildBundleConfigFiles(b)
+	if len(files) != 0 {
+		t.Errorf("empty bundle should produce no files; got %d", len(files))
+	}
+}
+
+// ---------- findConfigDir ----------
+
+func TestFindConfigDir_ExactMatch(t *testing.T) {
+	dir := t.TempDir()
+	sub := filepath.Join(dir, "ws-abc")
+	if err := os.MkdirAll(sub, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(sub, "config.yaml"), []byte("name: my-workspace\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got := findConfigDir(dir, "my-workspace")
+	if got != sub {
+		t.Errorf("got %q; want %q", got, sub)
+	}
+}
+
+func TestFindConfigDir_FallbackToFirst(t *testing.T) {
+	dir := t.TempDir()
+	sub1 := filepath.Join(dir, "ws-1")
+	sub2 := filepath.Join(dir, "ws-2")
+	os.MkdirAll(sub1, 0o755)
+	os.MkdirAll(sub2, 0o755)
+	os.WriteFile(filepath.Join(sub1, "config.yaml"), []byte("name: other\n"), 0o644)
+	os.WriteFile(filepath.Join(sub2, "config.yaml"), []byte("name: another\n"), 0o644)
+
+	got := findConfigDir(dir, "nonexistent")
+	if got != sub1 {
+		t.Errorf("no match → fallback to first; got %q; want %q", got, sub1)
+	}
+}
+
+func TestFindConfigDir_NoMatchNoFallback(t *testing.T) {
+	dir := t.TempDir()
+	// No subdirectories
+	got := findConfigDir(dir, "anything")
+	if got != "" {
+		t.Errorf("no dirs → want empty; got %q", got)
+	}
+}
+
+func TestFindConfigDir_UnreadableDir(t *testing.T) {
+	dir := t.TempDir()
+	got := findConfigDir(dir, "anything")
+	if got != "" {
+		t.Errorf("unreadable top-level → want empty; got %q", got)
+	}
+}