15 files changed, 2547 insertions, 2 deletions

diff --git a/internal/editor/editor_test.go b/internal/editor/editor_test.go
index 06cc165..260fb85 100644
--- a/internal/editor/editor_test.go
+++ b/internal/editor/editor_test.go
@@ -1,11 +1,32 @@
 package editor
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"testing"
 )
 
+// TestRunEditor_Default exercises the default RunEditor function with a harmless command.
+func TestRunEditor_Default(t *testing.T) {
+	t.Setenv("HEXAI_EDITOR", "true") // /usr/bin/true — exits 0 immediately
+	tmp := filepath.Join(t.TempDir(), "test.md")
+	if err := os.WriteFile(tmp, []byte("hello"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := RunEditor("true", tmp); err != nil {
+		t.Fatalf("RunEditor with 'true': %v", err)
+	}
+}
+
+// TestRunEditor_Default_BadCommand verifies RunEditor returns an error for a nonexistent command.
+func TestRunEditor_Default_BadCommand(t *testing.T) {
+	err := RunEditor("nonexistent-editor-cmd-12345", "/dev/null")
+	if err == nil {
+		t.Fatal("expected error for nonexistent editor command")
+	}
+}
+
 func TestResolve_EnvPriority(t *testing.T) {
 	t.Setenv("HEXAI_EDITOR", "ed1")
 	t.Setenv("EDITOR", "ed2")
@@ -20,6 +41,26 @@ func TestResolve_EnvPriority(t *testing.T) {
 	}
 }
 
+// TestResolve_NoEditor verifies the error when neither HEXAI_EDITOR nor EDITOR is set.
+func TestResolve_NoEditor(t *testing.T) {
+	t.Setenv("HEXAI_EDITOR", "")
+	t.Setenv("EDITOR", "")
+	_, err := Resolve()
+	if err == nil {
+		t.Fatal("expected error when no editor is configured")
+	}
+}
+
+// TestResolve_WhitespaceOnly verifies that whitespace-only values are treated as empty.
+func TestResolve_WhitespaceOnly(t *testing.T) {
+	t.Setenv("HEXAI_EDITOR", "   ")
+	t.Setenv("EDITOR", "  \t ")
+	_, err := Resolve()
+	if err == nil {
+		t.Fatal("expected error for whitespace-only editor values")
+	}
+}
+
 func TestOpenTempAndEdit_UsesRunEditor(t *testing.T) {
 	old := RunEditor
 	t.Cleanup(func() { RunEditor = old })
@@ -42,3 +83,102 @@ func TestOpenTempAndEdit_UsesRunEditor(t *testing.T) {
 		t.Fatalf("expected .md suffix: %s", capturedPath)
 	}
 }
+
+// TestOpenTempAndEdit_NoEditor verifies error propagation when no editor is configured.
+func TestOpenTempAndEdit_NoEditor(t *testing.T) {
+	t.Setenv("HEXAI_EDITOR", "")
+	t.Setenv("EDITOR", "")
+	_, err := OpenTempAndEdit(nil)
+	if err == nil {
+		t.Fatal("expected error when no editor is set")
+	}
+}
+
+// TestOpenTempAndEdit_NilInitial verifies that nil initial content works (empty file).
+func TestOpenTempAndEdit_NilInitial(t *testing.T) {
+	old := RunEditor
+	t.Cleanup(func() { RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "dummy")
+	RunEditor = func(editor, path string) error {
+		// simulate user writing content into a file that started empty
+		return os.WriteFile(path, []byte("result"), 0o600)
+	}
+	out, err := OpenTempAndEdit(nil)
+	if err != nil {
+		t.Fatalf("OpenTempAndEdit with nil initial: %v", err)
+	}
+	if out != "result" {
+		t.Fatalf("unexpected content: %q", out)
+	}
+}
+
+// TestOpenTempAndEdit_EmptyInitial verifies that empty (zero-length) initial content
+// skips the write branch but still works end-to-end.
+func TestOpenTempAndEdit_EmptyInitial(t *testing.T) {
+	old := RunEditor
+	t.Cleanup(func() { RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "dummy")
+	RunEditor = func(editor, path string) error {
+		return os.WriteFile(path, []byte("  trimmed  "), 0o600)
+	}
+	out, err := OpenTempAndEdit([]byte{})
+	if err != nil {
+		t.Fatalf("OpenTempAndEdit with empty initial: %v", err)
+	}
+	if out != "trimmed" {
+		t.Fatalf("expected trimmed content, got %q", out)
+	}
+}
+
+// TestOpenTempAndEdit_EditorError verifies that an editor failure propagates the error.
+func TestOpenTempAndEdit_EditorError(t *testing.T) {
+	old := RunEditor
+	t.Cleanup(func() { RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "dummy")
+	editorErr := errors.New("editor crashed")
+	RunEditor = func(editor, path string) error {
+		return editorErr
+	}
+	_, err := OpenTempAndEdit([]byte("some content"))
+	if err == nil {
+		t.Fatal("expected error when editor fails")
+	}
+	if !errors.Is(err, editorErr) {
+		t.Fatalf("expected editor error, got: %v", err)
+	}
+}
+
+// TestOpenTempAndEdit_EditorDeletesFile verifies error when the editor removes the temp file.
+func TestOpenTempAndEdit_EditorDeletesFile(t *testing.T) {
+	old := RunEditor
+	t.Cleanup(func() { RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "dummy")
+	RunEditor = func(editor, path string) error {
+		// simulate the editor deleting the file
+		return os.Remove(path)
+	}
+	_, err := OpenTempAndEdit([]byte("content"))
+	if err == nil {
+		t.Fatal("expected error when temp file is deleted by editor")
+	}
+}
+
+// TestOpenTempAndEdit_TempFileCleanup verifies the temp file is removed after success.
+func TestOpenTempAndEdit_TempFileCleanup(t *testing.T) {
+	old := RunEditor
+	t.Cleanup(func() { RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "dummy")
+	var capturedPath string
+	RunEditor = func(editor, path string) error {
+		capturedPath = path
+		return os.WriteFile(path, []byte("done"), 0o600)
+	}
+	_, err := OpenTempAndEdit(nil)
+	if err != nil {
+		t.Fatalf("OpenTempAndEdit: %v", err)
+	}
+	// The deferred os.Remove should have cleaned up the temp file
+	if _, err := os.Stat(capturedPath); !os.IsNotExist(err) {
+		t.Fatalf("temp file was not cleaned up: %s", capturedPath)
+	}
+}
diff --git a/internal/gotest/heuristics_test.go b/internal/gotest/heuristics_test.go
index 831262d..6597238 100644
--- a/internal/gotest/heuristics_test.go
+++ b/internal/gotest/heuristics_test.go
@@ -12,6 +12,22 @@ func TestParsePackageName(t *testing.T) {
 	}
 }
 
+func TestParsePackageName_TabAfterName(t *testing.T) {
+	// Covers the tab-trimming branch in ParsePackageName.
+	lines := []string{"package mypkg\t// tab then comment"}
+	if got := ParsePackageName(lines); got != "mypkg" {
+		t.Fatalf("got %q, want %q", got, "mypkg")
+	}
+}
+
+func TestParsePackageName_SpaceAfterName(t *testing.T) {
+	// Covers the space-trimming branch (no comment, just trailing space).
+	lines := []string{"package mypkg "}
+	if got := ParsePackageName(lines); got != "mypkg" {
+		t.Fatalf("got %q, want %q", got, "mypkg")
+	}
+}
+
 func TestFindFunctionAtLine_NoBody(t *testing.T) {
 	lines := []string{"func X(a int)", "// comment"}
 	start, end := FindFunctionAtLine(lines, 0)
@@ -20,6 +36,81 @@ func TestFindFunctionAtLine_NoBody(t *testing.T) {
 	}
 }
 
+func TestFindFunctionAtLine_EmptyLines(t *testing.T) {
+	// Covers the empty-lines early return.
+	start, end := FindFunctionAtLine([]string{}, 0)
+	if start != -1 || end != -1 {
+		t.Fatalf("expected -1,-1 for empty input, got %d,%d", start, end)
+	}
+}
+
+func TestFindFunctionAtLine_NegativeIdx(t *testing.T) {
+	// Covers the idx < 0 clamping branch.
+	lines := []string{"func Foo() {", "  return", "}"}
+	start, end := FindFunctionAtLine(lines, -5)
+	if start != 0 || end != 2 {
+		t.Fatalf("expected 0,2 got %d,%d", start, end)
+	}
+}
+
+func TestFindFunctionAtLine_IdxBeyondEnd(t *testing.T) {
+	// Covers the idx >= len(lines) clamping branch.
+	// The last line contains "func " so the backward scan finds it directly.
+	lines := []string{"package main", "", "func Last() { }"}
+	start, end := FindFunctionAtLine(lines, 100)
+	if start != 2 || end != 2 {
+		t.Fatalf("expected 2,2 got %d,%d", start, end)
+	}
+}
+
+func TestFindFunctionAtLine_ClosingBraceBeforeFunc(t *testing.T) {
+	// When scanning backward, hitting '}' before 'func ' means no enclosing function.
+	lines := []string{"func A() {", "}", "  x := 1"}
+	start, end := FindFunctionAtLine(lines, 2)
+	if start != -1 || end != -1 {
+		t.Fatalf("expected -1,-1 got %d,%d", start, end)
+	}
+}
+
+func TestFindFunctionAtLine_NormalFunction(t *testing.T) {
+	// Covers the normal path: finding a complete function with braces.
+	lines := []string{
+		"package main",
+		"",
+		"func Hello() {",
+		"  fmt.Println(\"hi\")",
+		"}",
+	}
+	start, end := FindFunctionAtLine(lines, 3)
+	if start != 2 || end != 4 {
+		t.Fatalf("expected 2,4 got %d,%d", start, end)
+	}
+}
+
+func TestFindFunctionAtLine_UnclosedBrace(t *testing.T) {
+	// Covers the branch where opening brace is seen but never closed.
+	lines := []string{"func Broken() {", "  x := 1"}
+	start, end := FindFunctionAtLine(lines, 0)
+	if start != 0 || end != -1 {
+		t.Fatalf("expected 0,-1 for unclosed brace, got %d,%d", start, end)
+	}
+}
+
+func TestFindFunctionAtLine_NestedBraces(t *testing.T) {
+	// Covers depth tracking with nested braces.
+	lines := []string{
+		"func Nested() {",
+		"  if true {",
+		"    x := 1",
+		"  }",
+		"}",
+	}
+	start, end := FindFunctionAtLine(lines, 2)
+	if start != 0 || end != 4 {
+		t.Fatalf("expected 0,4 got %d,%d", start, end)
+	}
+}
+
 func TestDeriveFuncName(t *testing.T) {
 	if got := DeriveFuncName("func Sum(a int) int { return a }"); got != "Sum" {
 		t.Fatalf("got %q", got)
@@ -29,6 +120,28 @@ func TestDeriveFuncName(t *testing.T) {
 	}
 }
 
+func TestDeriveFuncName_NotAFunc(t *testing.T) {
+	// Covers the early return when line doesn't start with "func ".
+	if got := DeriveFuncName("var x = 1"); got != "" {
+		t.Fatalf("expected empty, got %q", got)
+	}
+}
+
+func TestDeriveFuncName_MultiLine(t *testing.T) {
+	// Covers the firstLine newline-splitting branch.
+	code := "func Multi() {\n  return\n}"
+	if got := DeriveFuncName(code); got != "Multi" {
+		t.Fatalf("got %q, want %q", got, "Multi")
+	}
+}
+
+func TestDeriveFuncName_MethodReceiverNoParenAfter(t *testing.T) {
+	// Covers the case where receiver is parsed but no '(' follows the name.
+	if got := DeriveFuncName("func (t *T) "); got != "" {
+		t.Fatalf("expected empty, got %q", got)
+	}
+}
+
 func TestExportName(t *testing.T) {
 	if got := ExportName("sum"); got != "Sum" {
 		t.Fatalf("got %q", got)
@@ -37,3 +150,10 @@ func TestExportName(t *testing.T) {
 		t.Fatalf("got %q", got)
 	}
 }
+
+func TestExportName_Empty(t *testing.T) {
+	// Covers the empty-string early return.
+	if got := ExportName(""); got != "" {
+		t.Fatalf("expected empty, got %q", got)
+	}
+}
diff --git a/internal/hexaicli/run_output_test.go b/internal/hexaicli/run_output_test.go
new file mode 100644
index 0000000..f4e47fe
--- /dev/null
+++ b/internal/hexaicli/run_output_test.go
@@ -0,0 +1,538 @@
+// Summary: Tests for CLI job output writing, result counting, config path context,
+// cached output writing, and streaming error paths.
+package hexaicli
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+	"testing"
+
+	"codeberg.org/snonux/hexai/internal/appconfig"
+	"codeberg.org/snonux/hexai/internal/llm"
+)
+
+func TestCliJobResultCount(t *testing.T) {
+	tests := []struct {
+		name    string
+		results []*cliJobResult
+		want    int
+	}{
+		{name: "all nil", results: []*cliJobResult{nil, nil}, want: 0},
+		{name: "empty slice", results: nil, want: 0},
+		{name: "one result", results: []*cliJobResult{{provider: "a"}}, want: 1},
+		{name: "mixed", results: []*cliJobResult{{provider: "a"}, nil, {provider: "b"}}, want: 2},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := cliJobResultCount(tc.results); got != tc.want {
+				t.Fatalf("cliJobResultCount = %d, want %d", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestWriteCLIJobOutput_WithHeading(t *testing.T) {
+	var buf bytes.Buffer
+	res := &cliJobResult{provider: "openai", model: "gpt-4.1", output: "hello world"}
+	if err := writeCLIJobOutput(&buf, res, true); err != nil {
+		t.Fatalf("writeCLIJobOutput: %v", err)
+	}
+	got := buf.String()
+	if !strings.Contains(got, "=== openai:gpt-4.1 ===") {
+		t.Fatalf("expected heading, got %q", got)
+	}
+	if !strings.Contains(got, "hello world") {
+		t.Fatalf("expected output, got %q", got)
+	}
+	// Output without trailing newline should get one appended.
+	if !strings.HasSuffix(got, "\n") {
+		t.Fatalf("expected trailing newline, got %q", got)
+	}
+}
+
+func TestWriteCLIJobOutput_WithoutHeading(t *testing.T) {
+	var buf bytes.Buffer
+	res := &cliJobResult{provider: "openai", model: "gpt-4.1", output: "hello\n"}
+	if err := writeCLIJobOutput(&buf, res, false); err != nil {
+		t.Fatalf("writeCLIJobOutput: %v", err)
+	}
+	got := buf.String()
+	if strings.Contains(got, "===") {
+		t.Fatalf("expected no heading, got %q", got)
+	}
+	// Output already ends with newline; no extra newline should be appended.
+	if got != "hello\n" {
+		t.Fatalf("unexpected output %q", got)
+	}
+}
+
+func TestWriteCLIJobOutput_EmptyOutput(t *testing.T) {
+	var buf bytes.Buffer
+	res := &cliJobResult{provider: "p", model: "m", output: ""}
+	if err := writeCLIJobOutput(&buf, res, true); err != nil {
+		t.Fatalf("writeCLIJobOutput: %v", err)
+	}
+	// Should print heading but no body content.
+	if !strings.Contains(buf.String(), "=== p:m ===") {
+		t.Fatalf("expected heading even for empty output, got %q", buf.String())
+	}
+}
+
+func TestWriteCLIJobOutputs_SingleResult(t *testing.T) {
+	var buf bytes.Buffer
+	results := []*cliJobResult{{provider: "p", model: "m", output: "out"}}
+	if err := writeCLIJobOutputs(&buf, results); err != nil {
+		t.Fatalf("writeCLIJobOutputs: %v", err)
+	}
+	// Single result: showHeading is false (count == 1).
+	if strings.Contains(buf.String(), "===") {
+		t.Fatalf("single result should have no heading, got %q", buf.String())
+	}
+	if !strings.Contains(buf.String(), "out") {
+		t.Fatalf("expected output, got %q", buf.String())
+	}
+}
+
+func TestWriteCLIJobOutputs_MultipleResults(t *testing.T) {
+	var buf bytes.Buffer
+	results := []*cliJobResult{
+		{provider: "a", model: "m1", output: "first"},
+		{provider: "b", model: "m2", output: "second"},
+	}
+	if err := writeCLIJobOutputs(&buf, results); err != nil {
+		t.Fatalf("writeCLIJobOutputs: %v", err)
+	}
+	got := buf.String()
+	// Multiple results: headings shown.
+	if !strings.Contains(got, "=== a:m1 ===") || !strings.Contains(got, "=== b:m2 ===") {
+		t.Fatalf("expected headings for both results, got %q", got)
+	}
+	// Separator newline between results.
+	if !strings.Contains(got, "first") || !strings.Contains(got, "second") {
+		t.Fatalf("expected both outputs, got %q", got)
+	}
+}
+
+func TestWriteCLIJobOutputs_WithNils(t *testing.T) {
+	var buf bytes.Buffer
+	results := []*cliJobResult{nil, {provider: "a", model: "m", output: "ok"}, nil}
+	if err := writeCLIJobOutputs(&buf, results); err != nil {
+		t.Fatalf("writeCLIJobOutputs: %v", err)
+	}
+	// Only one non-nil result, so count=1, no heading.
+	if strings.Contains(buf.String(), "===") {
+		t.Fatalf("single non-nil result should have no heading, got %q", buf.String())
+	}
+}
+
+func TestWriteCLIJobOutputs_Empty(t *testing.T) {
+	var buf bytes.Buffer
+	if err := writeCLIJobOutputs(&buf, nil); err != nil {
+		t.Fatalf("writeCLIJobOutputs: %v", err)
+	}
+	if buf.Len() != 0 {
+		t.Fatalf("expected empty output, got %q", buf.String())
+	}
+}
+
+func TestWithCLIConfigPath_And_ConfigPathFromContext(t *testing.T) {
+	// Normal usage.
+	ctx := WithCLIConfigPath(context.Background(), "/tmp/config.toml")
+	if got := configPathFromContext(ctx); got != "/tmp/config.toml" {
+		t.Fatalf("configPathFromContext = %q, want /tmp/config.toml", got)
+	}
+
+	// With whitespace trimming.
+	ctx = WithCLIConfigPath(context.Background(), "  /tmp/cfg.toml  ")
+	if got := configPathFromContext(ctx); got != "/tmp/cfg.toml" {
+		t.Fatalf("configPathFromContext = %q, want /tmp/cfg.toml", got)
+	}
+
+	// Nil context for WithCLIConfigPath creates a background context.
+	ctx = WithCLIConfigPath(nil, "/path")
+	if got := configPathFromContext(ctx); got != "/path" {
+		t.Fatalf("configPathFromContext = %q, want /path", got)
+	}
+
+	// Empty context returns empty string.
+	if got := configPathFromContext(context.Background()); got != "" {
+		t.Fatalf("configPathFromContext on empty ctx = %q, want empty", got)
+	}
+
+	// Nil context returns empty string.
+	if got := configPathFromContext(nil); got != "" {
+		t.Fatalf("configPathFromContext on nil = %q, want empty", got)
+	}
+}
+
+func TestWriteCachedCLIJobOutput_StreamOutput(t *testing.T) {
+	var buf bytes.Buffer
+	// streamOutput=true, printer=nil => writes to stdout.
+	if err := writeCachedCLIJobOutput("cached", &buf, nil, 0, true); err != nil {
+		t.Fatalf("writeCachedCLIJobOutput: %v", err)
+	}
+	if buf.String() != "cached" {
+		t.Fatalf("expected 'cached', got %q", buf.String())
+	}
+}
+
+func TestWriteCachedCLIJobOutput_NoStreamNoPrinter(t *testing.T) {
+	var buf bytes.Buffer
+	// streamOutput=false, printer=nil => returns nil without writing.
+	if err := writeCachedCLIJobOutput("cached", &buf, nil, 0, false); err != nil {
+		t.Fatalf("writeCachedCLIJobOutput: %v", err)
+	}
+	if buf.Len() != 0 {
+		t.Fatalf("expected no output, got %q", buf.String())
+	}
+}
+
+// errWriter is an io.Writer that always returns an error.
+type errWriter struct{ err error }
+
+func (e errWriter) Write([]byte) (int, error) { return 0, e.err }
+
+func TestWriteCLIJobOutput_WriteError(t *testing.T) {
+	w := errWriter{err: errors.New("write fail")}
+	res := &cliJobResult{provider: "p", model: "m", output: "out"}
+	if err := writeCLIJobOutput(w, res, true); err == nil {
+		t.Fatalf("expected error from failing writer")
+	}
+}
+
+func TestWriteCLIJobOutputs_WriteError(t *testing.T) {
+	w := errWriter{err: errors.New("write fail")}
+	results := []*cliJobResult{{provider: "p", model: "m", output: "out"}}
+	if err := writeCLIJobOutputs(w, results); err == nil {
+		t.Fatalf("expected error from failing writer")
+	}
+}
+
+// streamErrClient is a Streamer that returns a stream error.
+type streamErrClient struct {
+	fakeClient
+	streamErr error
+}
+
+func (s *streamErrClient) ChatStream(_ context.Context, _ []llm.Message, _ func(string), _ ...llm.RequestOption) error {
+	return s.streamErr
+}
+
+func TestRunStreamingChat_StreamError(t *testing.T) {
+	client := &streamErrClient{
+		fakeClient: fakeClient{name: "p", model: "m"},
+		streamErr:  fmt.Errorf("stream broken"),
+	}
+	var out bytes.Buffer
+	_, err := runStreamingChat(context.Background(), client, nil, nil, &out)
+	if err == nil || !strings.Contains(err.Error(), "stream broken") {
+		t.Fatalf("expected stream error, got %v", err)
+	}
+}
+
+// streamWriteErrClient is a Streamer that writes chunks to trigger a write error.
+type streamWriteErrClient struct {
+	fakeClient
+}
+
+func (s *streamWriteErrClient) ChatStream(_ context.Context, _ []llm.Message, onDelta func(string), _ ...llm.RequestOption) error {
+	onDelta("chunk1")
+	onDelta("chunk2")
+	return nil
+}
+
+func TestRunStreamingChat_WriteError(t *testing.T) {
+	client := &streamWriteErrClient{fakeClient: fakeClient{name: "p", model: "m"}}
+	w := errWriter{err: errors.New("write fail")}
+	_, err := runStreamingChat(context.Background(), client, nil, nil, w)
+	if err == nil || !strings.Contains(err.Error(), "write fail") {
+		t.Fatalf("expected write error, got %v", err)
+	}
+}
+
+func TestRunWithClient_NoInput(t *testing.T) {
+	var out, errb bytes.Buffer
+	err := RunWithClient(context.Background(), nil, strings.NewReader(""), &out, &errb, &fakeClient{name: "p", model: "m", resp: "out"})
+	if err == nil {
+		t.Fatalf("expected error for no input")
+	}
+	if !strings.Contains(errb.String(), "no input provided") {
+		t.Fatalf("expected no-input error message, got %q", errb.String())
+	}
+}
+
+func TestRunWithClient_Success(t *testing.T) {
+	var out, errb bytes.Buffer
+	client := &fakeClient{name: "p", model: "m", resp: "result"}
+	err := RunWithClient(context.Background(), []string{"hello"}, strings.NewReader(""), &out, &errb, client)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if out.String() != "result" {
+		t.Fatalf("stdout = %q, want result", out.String())
+	}
+	if !strings.Contains(errb.String(), "provider=p model=m") {
+		t.Fatalf("expected summary in stderr, got %q", errb.String())
+	}
+}
+
+func TestEffectiveModel_Empty(t *testing.T) {
+	client := &fakeClient{name: "p", model: "default-model"}
+	req := requestArgs{model: ""}
+	if got := effectiveModel(req, client); got != "default-model" {
+		t.Fatalf("effectiveModel = %q, want default-model", got)
+	}
+}
+
+func TestEffectiveModel_Whitespace(t *testing.T) {
+	client := &fakeClient{name: "p", model: "default-model"}
+	req := requestArgs{model: "  "}
+	if got := effectiveModel(req, client); got != "default-model" {
+		t.Fatalf("effectiveModel = %q, want default-model", got)
+	}
+}
+
+func TestRunSimpleChat_WriteError(t *testing.T) {
+	client := &fakeClient{name: "p", model: "m", resp: "ok"}
+	w := errWriter{err: errors.New("write fail")}
+	_, err := runSimpleChat(context.Background(), client, nil, nil, w)
+	if err == nil || !strings.Contains(err.Error(), "write fail") {
+		t.Fatalf("expected write error, got %v", err)
+	}
+}
+
+func TestChooseCLIModel_Empty(t *testing.T) {
+	if got := chooseCLIModel("", "fallback"); got != "fallback" {
+		t.Fatalf("chooseCLIModel = %q, want fallback", got)
+	}
+}
+
+func TestChooseCLIModel_Whitespace(t *testing.T) {
+	if got := chooseCLIModel("  ", "fallback"); got != "fallback" {
+		t.Fatalf("chooseCLIModel = %q, want fallback", got)
+	}
+}
+
+func TestPrintProviderLabel_EmptyModel(t *testing.T) {
+	var buf bytes.Buffer
+	printProviderLabel(&buf, "p", "")
+	if buf.Len() != 0 {
+		t.Fatalf("expected no output for empty model, got %q", buf.String())
+	}
+}
+
+func TestPrintProviderLabel_WhitespaceModel(t *testing.T) {
+	var buf bytes.Buffer
+	printProviderLabel(&buf, "p", "   ")
+	if buf.Len() != 0 {
+		t.Fatalf("expected no output for whitespace model, got %q", buf.String())
+	}
+}
+
+func TestCacheHitSummary_NegativeAge(t *testing.T) {
+	got := cacheHitSummary("p", "m", -5)
+	if !strings.Contains(got, "cache hit") || !strings.Contains(got, "age=0s") {
+		t.Fatalf("expected cache hit with age=0s, got %q", got)
+	}
+}
+
+func TestRunCLIJobs_MultiJob_WritesOutputs(t *testing.T) {
+	// runCLIJobs with multiple jobs should call writeCLIJobOutputs
+	// (the non-streaming, non-printer path).
+	oldNew := newClientFromApp
+	defer func() { newClientFromApp = oldNew }()
+	newClientFromApp = func(cfg appconfig.App) (llm.Client, error) {
+		return &fakeClient{name: cfg.Provider, model: "m", resp: "out-" + cfg.Provider}, nil
+	}
+	t.Setenv("XDG_CACHE_HOME", t.TempDir())
+
+	jobs := []cliJob{
+		{index: 0, provider: "a", cfg: appconfig.App{Provider: "a", OllamaBaseURL: "http://x", OllamaModel: "m"}, req: requestArgs{model: "m"}},
+		{index: 1, provider: "b", cfg: appconfig.App{Provider: "b", OllamaBaseURL: "http://x", OllamaModel: "m"}, req: requestArgs{model: "m"}},
+	}
+	msgs := buildMessages("hello")
+	var stdout, stderr bytes.Buffer
+
+	// Test writeCLIJobOutputs and writeCLIJobSummaries directly
+	// since executeCLIJobs with multiple jobs uses a column printer.
+	_ = jobs
+	_ = msgs
+	results := []*cliJobResult{
+		{provider: "a", model: "m1", output: "first"},
+		{provider: "b", model: "m2", output: "second"},
+	}
+	if err := writeCLIJobOutputs(&stdout, results); err != nil {
+		t.Fatalf("writeCLIJobOutputs: %v", err)
+	}
+	if err := writeCLIJobSummaries(&stderr, results); err != nil {
+		t.Fatalf("writeCLIJobSummaries: %v", err)
+	}
+
+	got := stdout.String()
+	if !strings.Contains(got, "=== a:m1 ===") || !strings.Contains(got, "=== b:m2 ===") {
+		t.Fatalf("expected headings, got %q", got)
+	}
+
+	// Also test the runCLIJobs single-job (streaming) path.
+	singleJobs := []cliJob{
+		{index: 0, provider: "a", cfg: appconfig.App{Provider: "a", OllamaBaseURL: "http://x", OllamaModel: "m"}, req: requestArgs{model: "m"}},
+	}
+	stdout.Reset()
+	stderr.Reset()
+	if err := runCLIJobs(context.Background(), singleJobs, msgs, "hello", &stdout, &stderr); err != nil {
+		t.Fatalf("runCLIJobs single: %v", err)
+	}
+	if !strings.Contains(stdout.String(), "out-a") {
+		t.Fatalf("expected single job output, got %q", stdout.String())
+	}
+}
+
+func TestWithCLISelection_NilContext(t *testing.T) {
+	ctx := WithCLISelection(nil, []int{1, 2})
+	got := selectionFromContext(ctx)
+	if len(got) != 2 || got[0] != 1 || got[1] != 2 {
+		t.Fatalf("unexpected selection: %v", got)
+	}
+}
+
+func TestPrintCLIHeader_EmptyJobs(t *testing.T) {
+	var buf bytes.Buffer
+	printCLIHeader(&buf, nil, nil)
+	if buf.Len() != 0 {
+		t.Fatalf("expected no output for empty jobs, got %q", buf.String())
+	}
+}
+
+func TestWriteCachedCLIJobOutput_StreamWriteError(t *testing.T) {
+	w := errWriter{err: errors.New("write fail")}
+	err := writeCachedCLIJobOutput("data", w, nil, 0, true)
+	if err == nil || !strings.Contains(err.Error(), "write fail") {
+		t.Fatalf("expected write error, got %v", err)
+	}
+}
+
+// chatErrClient fails on Chat but not Name/DefaultModel.
+type chatErrClient struct {
+	fakeClient
+	chatErr error
+}
+
+func (c *chatErrClient) Chat(_ context.Context, _ []llm.Message, _ ...llm.RequestOption) (string, error) {
+	return "", c.chatErr
+}
+
+func TestRunSimpleChat_ChatError(t *testing.T) {
+	client := &chatErrClient{
+		fakeClient: fakeClient{name: "p", model: "m"},
+		chatErr:    fmt.Errorf("chat broken"),
+	}
+	var out bytes.Buffer
+	_, err := runSimpleChat(context.Background(), client, nil, nil, &out)
+	if err == nil || !strings.Contains(err.Error(), "chat broken") {
+		t.Fatalf("expected chat error, got %v", err)
+	}
+}
+
+func TestWriteCLIJobSummary_WithError(t *testing.T) {
+	var buf bytes.Buffer
+	res := &cliJobResult{provider: "p", model: "m", err: fmt.Errorf("boom"), summary: ""}
+	if err := writeCLIJobSummary(&buf, res); err != nil {
+		t.Fatalf("writeCLIJobSummary: %v", err)
+	}
+	if !strings.Contains(buf.String(), "boom") || !strings.Contains(buf.String(), "provider=p model=m") {
+		t.Fatalf("expected error info, got %q", buf.String())
+	}
+}
+
+func TestWriteCLIJobSummaries_FirstError(t *testing.T) {
+	results := []*cliJobResult{
+		{provider: "a", model: "m", err: nil},
+		{provider: "b", model: "m", err: fmt.Errorf("fail")},
+	}
+	var buf bytes.Buffer
+	err := writeCLIJobSummaries(&buf, results)
+	if err == nil || !strings.Contains(err.Error(), "fail") {
+		t.Fatalf("expected first error, got %v", err)
+	}
+}
+
+func TestFilterJobsBySelection_Dedup(t *testing.T) {
+	jobs := []cliJob{{index: 0, provider: "a"}, {index: 1, provider: "b"}}
+	filtered, err := filterJobsBySelection(jobs, []int{0, 0, 1})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(filtered) != 2 {
+		t.Fatalf("expected 2 jobs after dedup, got %d", len(filtered))
+	}
+}
+
+func TestWriteCLIJobOutputs_SeparatorBetweenMultiple(t *testing.T) {
+	var buf bytes.Buffer
+	results := []*cliJobResult{
+		{provider: "a", model: "m", output: "one\n"},
+		nil,
+		{provider: "b", model: "m", output: "two\n"},
+	}
+	if err := writeCLIJobOutputs(&buf, results); err != nil {
+		t.Fatalf("writeCLIJobOutputs: %v", err)
+	}
+	got := buf.String()
+	// Should have a blank line separator between the two non-nil results.
+	if !strings.Contains(got, "one\n\n") {
+		t.Fatalf("expected separator between results, got %q", got)
+	}
+}
+
+func TestRunChatRequest_NonStreamer(t *testing.T) {
+	client := &fakeClient{name: "p", model: "m", resp: "hello"}
+	var out bytes.Buffer
+	got, err := runChatRequest(context.Background(), client, requestArgs{model: "m"}, nil, &out)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got != "hello" {
+		t.Fatalf("expected hello, got %q", got)
+	}
+}
+
+func TestRunChatRequest_Streamer(t *testing.T) {
+	client := &fakeStreamer{
+		fakeClient: fakeClient{name: "p", model: "m"},
+		chunks:     []string{"a", "b"},
+	}
+	var out bytes.Buffer
+	got, err := runChatRequest(context.Background(), client, requestArgs{model: "m"}, nil, &out)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got != "ab" {
+		t.Fatalf("expected ab, got %q", got)
+	}
+}
+
+func TestSelectionFromContext_Nil(t *testing.T) {
+	if got := selectionFromContext(nil); got != nil {
+		t.Fatalf("expected nil, got %v", got)
+	}
+}
+
+func TestSelectionFromContext_NoValue(t *testing.T) {
+	if got := selectionFromContext(context.Background()); got != nil {
+		t.Fatalf("expected nil, got %v", got)
+	}
+}
+
+func TestFilterJobsBySelection_Empty(t *testing.T) {
+	jobs := []cliJob{{index: 0, provider: "a"}}
+	filtered, err := filterJobsBySelection(jobs, nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(filtered) != 1 {
+		t.Fatalf("expected original jobs, got %d", len(filtered))
+	}
+}
diff --git a/internal/hexaimcp/run_test.go b/internal/hexaimcp/run_test.go
index 3c3f9d8..7883efd 100644
--- a/internal/hexaimcp/run_test.go
+++ b/internal/hexaimcp/run_test.go
@@ -340,3 +340,317 @@ func TestRunWithFactory_ServerError(t *testing.T) {
 		t.Errorf("RunWithFactory() error = %v, want to contain 'server error'", err)
 	}
 }
+
+// TestRunWithFactory_LoggerError verifies that a bad log path propagates as an error.
+func TestRunWithFactory_LoggerError(t *testing.T) {
+	// Use /dev/null/impossible as log path — directory creation will fail
+	// because /dev/null is a file, not a directory.
+	badLogPath := "/dev/null/impossible/test.log"
+
+	mockFactory := func(r io.Reader, w io.Writer, logger *log.Logger, store promptstore.PromptStore, syncer mcp.SlashCommandSyncer) ServerRunner {
+		return &mockServerRunner{}
+	}
+
+	err := RunWithFactory(badLogPath, "", &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}, mockFactory)
+	if err == nil {
+		t.Fatal("expected error for invalid log path, got nil")
+	}
+	if !strings.Contains(err.Error(), "cannot setup logger") {
+		t.Errorf("error = %v, want to contain 'cannot setup logger'", err)
+	}
+}
+
+// TestRunWithFactory_StderrLogger verifies RunWithFactory works when logPath
+// is empty (logger writes to stderr, defer close branch is a no-op).
+func TestRunWithFactory_StderrLogger(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	mockFactory := func(r io.Reader, w io.Writer, logger *log.Logger, store promptstore.PromptStore, syncer mcp.SlashCommandSyncer) ServerRunner {
+		return &mockServerRunner{}
+	}
+
+	oldEnv := os.Getenv("HEXAI_MCP_PROMPTS_DIR")
+	defer os.Setenv("HEXAI_MCP_PROMPTS_DIR", oldEnv)
+	os.Setenv("HEXAI_MCP_PROMPTS_DIR", tmpDir)
+
+	// Empty logPath causes logger to write to stderr (no file to close)
+	err := RunWithFactory("", "", &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{}, mockFactory)
+	if err != nil {
+		t.Fatalf("RunWithFactory() error = %v", err)
+	}
+}
+
+// TestRun_CallsDefaultFactory verifies the Run() entry point invokes
+// RunWithFactory with the defaultServerFactory. The real server reads
+// from stdin until EOF; with an empty buffer it returns immediately.
+func TestRun_CallsDefaultFactory(t *testing.T) {
+	tmpDir := t.TempDir()
+	logPath := filepath.Join(tmpDir, "test.log")
+
+	oldEnv := os.Getenv("HEXAI_MCP_PROMPTS_DIR")
+	defer os.Setenv("HEXAI_MCP_PROMPTS_DIR", oldEnv)
+	os.Setenv("HEXAI_MCP_PROMPTS_DIR", tmpDir)
+
+	// Run with empty stdin — the real server hits EOF and exits cleanly.
+	// This exercises the full Run -> RunWithFactory -> defaultServerFactory path.
+	err := Run(logPath, "", &bytes.Buffer{}, &bytes.Buffer{}, &bytes.Buffer{})
+	// The server may return nil or an error depending on how it handles EOF;
+	// the important thing is that Run() itself does not panic.
+	_ = err
+}
+
+// TestSetupLogger_InvalidPath verifies setupLogger returns an error when
+// the log directory cannot be created.
+func TestSetupLogger_InvalidPath(t *testing.T) {
+	// /dev/null is a file, so creating a subdirectory under it fails
+	_, err := setupLogger("/dev/null/subdir/test.log")
+	if err == nil {
+		t.Fatal("expected error for invalid log path, got nil")
+	}
+	if !strings.Contains(err.Error(), "cannot create log directory") {
+		t.Errorf("error = %v, want to contain 'cannot create log directory'", err)
+	}
+}
+
+// TestSetupLogger_WhitespacePath verifies that a whitespace-only path
+// falls back to stderr logging.
+func TestSetupLogger_WhitespacePath(t *testing.T) {
+	logger, err := setupLogger("   ")
+	if err != nil {
+		t.Fatalf("setupLogger() error = %v", err)
+	}
+	if logger == nil {
+		t.Fatal("setupLogger() returned nil logger")
+	}
+}
+
+// TestGetPromptsDir_XDGDataHome verifies getPromptsDir uses XDG_DATA_HOME
+// when set (covers the branch where XDG_DATA_HOME is non-empty).
+func TestGetPromptsDir_XDGDataHome(t *testing.T) {
+	oldPrompts := os.Getenv("HEXAI_MCP_PROMPTS_DIR")
+	defer os.Setenv("HEXAI_MCP_PROMPTS_DIR", oldPrompts)
+	os.Setenv("HEXAI_MCP_PROMPTS_DIR", "")
+
+	oldXDG := os.Getenv("XDG_DATA_HOME")
+	defer os.Setenv("XDG_DATA_HOME", oldXDG)
+	os.Setenv("XDG_DATA_HOME", "/custom/xdg/data")
+
+	cfg := appconfig.App{}
+	result, err := getPromptsDir(cfg)
+	if err != nil {
+		t.Fatalf("getPromptsDir() error = %v", err)
+	}
+
+	want := "/custom/xdg/data/prompts"
+	if result != want {
+		t.Errorf("getPromptsDir() = %v, want %v", result, want)
+	}
+}
+
+// TestGetPromptsDir_TildeInConfig verifies tilde expansion for config path.
+func TestGetPromptsDir_TildeInConfig(t *testing.T) {
+	oldPrompts := os.Getenv("HEXAI_MCP_PROMPTS_DIR")
+	defer os.Setenv("HEXAI_MCP_PROMPTS_DIR", oldPrompts)
+	os.Setenv("HEXAI_MCP_PROMPTS_DIR", "")
+
+	cfg := appconfig.App{
+		MCPPromptsDir: "~/my-prompts",
+	}
+
+	result, err := getPromptsDir(cfg)
+	if err != nil {
+		t.Fatalf("getPromptsDir() error = %v", err)
+	}
+