test: intial GenesisState Validate test (fetchai#99)

* test: intial GenesisState Validate test

* Fix: fix basic first tests

* Test: test Validate and NewGenesisState

* Fix: let AllowList be empty

* Tidy: goimports genesis_test.go

* Refactor: increase test coverage

* Refactor: remove unnecessary code and rename vars

x/airdrop/keeper/params.go

@@ -7,7 +7,7 @@ import (
 
 func (k Keeper) GetWhiteListClients(ctx sdk.Context) []string {
 	var res []string
-	k.paramSpace.Get(ctx, types.KeyWhiteList, &res)
+	k.paramSpace.GetIfExists(ctx, types.KeyWhiteList, &res)
 	return res
 }
 

x/airdrop/types/genesis_test.go

@@ -0,0 +1,63 @@
+package types_test
+
+import (
+	"testing"
+
+	"github.com/cosmos/cosmos-sdk/x/airdrop/types"
+	"github.com/stretchr/testify/require"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+var (
+	addr        = sdk.AccAddress([]byte("addr________________"))
+	invalidAddr = sdk.AccAddress([]byte("\n\n\n\n\taddr________________\t\n\n\n\n\n"))
+)
+
+func TestNewGenesisState(t *testing.T) {
+	p := types.NewParams()
+	expectedFunds := []types.ActiveFund{
+		{
+			Sender: addr.String(),
+			Fund: &types.Fund{
+				Amount:     &sdk.Coin{Denom: "test", Amount: sdk.NewInt(10)},
+				DripAmount: sdk.NewInt(1),
+			},
+		},
+	}
+	expectedState := &types.GenesisState{
+		Params: p,
+		Funds:  expectedFunds,
+	}
+	require.Equal(t, expectedState.GetFunds(), expectedFunds)
+	require.Equal(t, expectedState.Params, p)
+}
+
+func TestValidateGenesisState(t *testing.T) {
+	p1 := types.Params{
+		AllowList: []string{
+			addr.String(), // valid address
+		},
+	}
+	p2 := types.Params{
+		AllowList: []string{
+			invalidAddr.String(), // invalid address
+		},
+	}
+	funds := []types.ActiveFund{
+		{
+			Sender: addr.String(),
+			Fund: &types.Fund{
+				Amount: &sdk.Coin{
+					Denom:  "test",
+					Amount: sdk.NewInt(10),
+				},
+				DripAmount: sdk.NewInt(1),
+			},
+		},
+	}
+	gen1 := types.NewGenesisState(p1, funds)
+	gen2 := types.NewGenesisState(p2, funds)
+	require.NoError(t, gen1.Validate())
+	require.Error(t, gen2.Validate())
+}