task dac9b1e5: avoid LSP startup panic on StateDir failure

2 files changed, 18 insertions, 4 deletions

diff --git a/cmd/hexai-lsp-server/main.go b/cmd/hexai-lsp-server/main.go
index c8cdd8f..e3e458d 100644
--- a/cmd/hexai-lsp-server/main.go
+++ b/cmd/hexai-lsp-server/main.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"codeberg.org/snonux/hexai/internal"
@@ -40,13 +41,11 @@ func defaultConfigPath() string {
 }
 
 // defaultLogPath returns the default LSP log file path in the state directory.
-// Falls back to /tmp if state directory cannot be determined.
-// defaultLogPath returns the default LSP log file path in the state directory.
-// Panics if state directory cannot be created.
+// Falls back to the system temp directory if the state directory is unavailable.
 func defaultLogPath() string {
 	stateDir, err := appconfig.StateDir()
 	if err != nil {
-		panic(fmt.Sprintf("cannot create state directory: %v", err))
+		return filepath.Join(os.TempDir(), "hexai-lsp-server.log")
 	}
 	return fmt.Sprintf("%s/hexai-lsp-server.log", stateDir)
 }
diff --git a/cmd/hexai-lsp-server/main_test.go b/cmd/hexai-lsp-server/main_test.go
index 5563e3d..9861f54 100644
--- a/cmd/hexai-lsp-server/main_test.go
+++ b/cmd/hexai-lsp-server/main_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"log"
 	"os"
+	"path/filepath"
 	"testing"
 )
 
@@ -20,3 +21,17 @@ func TestMain_Version(t *testing.T) {
 		t.Fatalf("expected version log")
 	}
 }
+
+func TestDefaultLogPathFallsBackToTempDirOnStateDirFailure(t *testing.T) {
+	stateHome := filepath.Join(t.TempDir(), "state-home-file")
+	if err := os.WriteFile(stateHome, []byte("not-a-directory"), 0o644); err != nil {
+		t.Fatalf("write state home marker: %v", err)
+	}
+	t.Setenv("XDG_STATE_HOME", stateHome)
+
+	got := defaultLogPath()
+	want := filepath.Join(os.TempDir(), "hexai-lsp-server.log")
+	if got != want {
+		t.Fatalf("expected temp-dir fallback %q, got %q", want, got)
+	}
+}