test: cover the chat access policy and bootstrap guards

ChatAccess admits only chat-group members to context bm/1 and manages
nothing; the chat context oversees nothing and its loader knows only
id 1; /chat and /chat/members need a caller and a database. The
migration count rises to 15 for the chat group seed.

classes/chat_context_test.go

@@ -0,0 +1,107 @@
+package classes_test
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"git.golem15.com/jakub/sm-bm-plugin/classes"
+	"gorm.io/gorm"
+)
+
+// members is an injected group check: user 7 is in studenci, user 9 is in
+// moderatorzy only, user 13 makes the check fail.
+func members(_ context.Context, _ *gorm.DB, userID uint, group string) (bool, error) {
+	switch {
+	case userID == 13:
+		return false, errors.New("database down")
+	case group == "studenci":
+		return userID == 7, nil
+	case group == "moderatorzy":
+		return userID == 9 || userID == 7, nil
+	}
+	return false, nil
+}
+
+func TestChatAccess(t *testing.T) {
+	db := func() *gorm.DB { return &gorm.DB{} }
+	access := classes.NewChatAccess(db, "studenci", members)
+	ctx := t.Context()
+	for _, c := range []struct {
+		name        string
+		userID      uint
+		contextType string
+		contextID   uint
+		want        bool
+	}{
+		{"member of bm/1", 7, "bm", 1, true},
+		{"other context type", 7, "channel", 1, false},
+		{"other context id", 7, "bm", 2, false},
+		{"non-member", 8, "bm", 1, false},
+		{"moderator only", 9, "bm", 1, false},
+		{"check fails", 13, "bm", 1, false},
+		{"no user", 0, "bm", 1, false},
+	} {
+		if got := access.CanAccessContext(ctx, c.userID, c.contextType, c.contextID); got != c.want {
+			t.Errorf("%s: CanAccessContext = %v, want %v", c.name, got, c.want)
+		}
+		if access.CanManageContext(ctx, c.userID, c.contextType, c.contextID) {
+			t.Errorf("%s: CanManageContext = true; nobody creates channels", c.name)
+		}
+	}
+	noDB := classes.NewChatAccess(func() *gorm.DB { return nil }, "studenci", members)
+	if noDB.CanAccessContext(ctx, 7, "bm", 1) {
+		t.Error("CanAccessContext without a database = true, want false")
+	}
+	nilFunc := classes.NewChatAccess(nil, "studenci", members)
+	if nilFunc.CanAccessContext(ctx, 7, "bm", 1) {
+		t.Error("CanAccessContext without a database func = true, want false")
+	}
+	noGroup := classes.NewChatAccess(db, "", members)
+	if noGroup.CanAccessContext(ctx, 7, "bm", 1) {
+		t.Error("CanAccessContext without a chat group = true, want false")
+	}
+}
+
+func TestChatContext(t *testing.T) {
+	ctx := t.Context()
+	c := classes.NewChatContext(&gorm.DB{}, "studenci", "moderatorzy").WithMembership(members)
+	if c.ID() != classes.ChatContextID || c.ID() != 1 || c.Type() != "bm" {
+		t.Errorf("context = %s/%d, want bm/1", c.Type(), c.ID())
+	}
+	if !c.ChatEnabled() || c.GroupName() != "ogólny" {
+		t.Errorf("ChatEnabled %v GroupName %q", c.ChatEnabled(), c.GroupName())
+	}
+	if c.BroadcastChannel() != "chat:context:1" {
+		t.Errorf("BroadcastChannel = %q, want chat:context:1", c.BroadcastChannel())
+	}
+	for _, id := range []uint{7, 9, 8} {
+		if ok, err := c.CanOverseeChats(ctx, id); ok || err != nil {
+			t.Errorf("CanOverseeChats(%d) = %v, %v; nobody oversees", id, ok, err)
+		}
+	}
+	if ok, err := c.HasMember(ctx, 7); !ok || err != nil {
+		t.Errorf("HasMember(7) = %v, %v, want true", ok, err)
+	}
+	if ok, err := c.HasMember(ctx, 9); ok || err != nil {
+		t.Errorf("HasMember(9) = %v, %v, want false (moderator group only)", ok, err)
+	}
+	if ok, _ := c.HasMember(ctx, 0); ok {
+		t.Error("HasMember(0) = true")
+	}
+	if _, err := c.HasMember(ctx, 13); err == nil {
+		t.Error("HasMember with a failing check returned no error")
+	}
+	if !c.CanActFor(ctx, 7, 7) || c.CanActFor(ctx, 7, 8) {
+		t.Error("CanActFor is not self-only")
+	}
+
+	load := classes.ChatContextLoader(func() string { return "studenci" }, func() string { return "moderatorzy" })
+	if got, err := load(ctx, &gorm.DB{}, 2); got != nil || err != nil {
+		t.Errorf("loader(2) = %v, %v, want nil, nil", got, err)
+	}
+	got, err := load(ctx, &gorm.DB{}, 1)
+	if err != nil || got == nil || got.ID() != 1 || got.Type() != "bm" {
+		t.Errorf("loader(1) = %v, %v, want the bm/1 context", got, err)
+	}
+}