test(coverage): raise engine+agent coverage above 50%

internal/agent/disk_test.go

@@ -0,0 +1,62 @@
+package agent
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestDirSize(t *testing.T) {
+	root := t.TempDir()
+	if err := os.WriteFile(filepath.Join(root, "a.bin"), make([]byte, 100), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(filepath.Join(root, "sub"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(root, "sub", "b.bin"), make([]byte, 250), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := DirSize(root)
+	if err != nil {
+		t.Fatalf("DirSize error: %v", err)
+	}
+	if got != 350 {
+		t.Errorf("DirSize = %d, want 350", got)
+	}
+}
+
+func TestDirSizeEmpty(t *testing.T) {
+	got, err := DirSize(t.TempDir())
+	if err != nil {
+		t.Fatalf("DirSize empty dir error: %v", err)
+	}
+	if got != 0 {
+		t.Errorf("DirSize empty = %d, want 0", got)
+	}
+}
+
+func TestDirSizeMissing(t *testing.T) {
+	// Walk skips unreadable entries — missing path returns 0 with no error.
+	got, err := DirSize("/nonexistent/path/zzz")
+	if err != nil {
+		t.Errorf("DirSize on missing path = err %v, want nil", err)
+	}
+	if got != 0 {
+		t.Errorf("DirSize on missing path = %d, want 0", got)
+	}
+}
+
+func TestDiskInfoCurrentDir(t *testing.T) {
+	free, total, err := DiskInfo(".")
+	if err != nil {
+		t.Fatalf("DiskInfo: %v", err)
+	}
+	if total <= 0 {
+		t.Errorf("total bytes should be > 0, got %d", total)
+	}
+	if free > total {
+		t.Errorf("free (%d) should not exceed total (%d)", free, total)
+	}
+}

internal/agent/process_unix_test.go

@@ -0,0 +1,22 @@
+//go:build !windows
+
+package agent
+
+import (
+	"os"
+	"testing"
+)
+
+func TestIsProcessAliveSelf(t *testing.T) {
+	if !IsProcessAlive(os.Getpid()) {
+		t.Errorf("self PID should be alive")
+	}
+}
+
+func TestIsProcessAliveBogus(t *testing.T) {
+	// PID 0 is reserved (signal 0 to PID 0 broadcasts to the whole pgrp).
+	// Pick a very high PID unlikely to exist.
+	if IsProcessAlive(0x7FFFFFFE) {
+		t.Errorf("very high PID should not be alive")
+	}
+}

internal/agent/taskstate_test.go

@@ -215,3 +215,56 @@ func TestLocalState_EmptySnapshot(t *testing.T) {
 		t.Errorf("expected 0 tasks, got %d", len(snap))
 	}
 }
+
+func TestTaskStateFromUpdate(t *testing.T) {
+	u := StatusUpdate{
+		TaskID:          "task-1",
+		Status:          "downloading",
+		Progress:        42,
+		DownloadedBytes: 1024,
+		TotalBytes:      4096,
+		SpeedBps:        100,
+		ETA:             30,
+		ResolvedMethod:  "torrent",
+		FileName:        "movie.mkv",
+		FilePath:        "/tmp/movie.mkv",
+		StreamURL:       "http://localhost/stream",
+		ErrorMessage:    "",
+	}
+	got := TaskStateFromUpdate(u)
+	if got.TaskID != "task-1" || got.Status != "downloading" || got.Progress != 42 {
+		t.Errorf("basic fields wrong: %+v", got)
+	}
+	if got.DownloadedBytes != 1024 || got.TotalBytes != 4096 || got.SpeedBps != 100 {
+		t.Errorf("byte fields wrong: %+v", got)
+	}
+	if got.ResolvedMethod != "torrent" || got.FileName != "movie.mkv" {
+		t.Errorf("method/name fields wrong: %+v", got)
+	}
+}
+
+func TestShortID(t *testing.T) {
+	if got := ShortID("abcdef1234567890"); got != "abcdef12" {
+		t.Errorf("ShortID = %q", got)
+	}
+	if got := ShortID("short"); got != "short" {
+		t.Errorf("ShortID short = %q", got)
+	}
+	if got := ShortID(""); got != "" {
+		t.Errorf("ShortID empty = %q", got)
+	}
+}
+
+func TestStateFilePath(t *testing.T) {
+	if got := StateFilePath(); got == "" {
+		t.Errorf("StateFilePath should not be empty")
+	}
+}
+
+func TestHTTPError(t *testing.T) {
+	e := &HTTPError{StatusCode: 404, Message: "not found"}
+	got := e.Error()
+	if got == "" || got == "API error 0: " {
+		t.Errorf("HTTPError.Error() unexpected: %q", got)
+	}
+}