Created test for LLEN handler

src/modules/list/commands.go

@@ -19,22 +19,21 @@ func handleLLen(ctx context.Context, cmd []string, server utils.Server, conn *ne
 	key := cmd[1]
 
 	if !server.KeyExists(key) {
-		// Key, does not exist, return
+		// If key does not exist, return 0
-		return nil, errors.New("LLEN command on non-list item")
+		return []byte(":0\r\n\r\n"), nil
 	}
 
 	_, err := server.KeyRLock(ctx, key)
 	if err != nil {
 		return nil, err
 	}
-	list, ok := server.GetValue(key).([]interface{})
+	defer server.KeyRUnlock(key)
-	server.KeyRUnlock(key)
 
-	if !ok {
+	if list, ok := server.GetValue(key).([]interface{}); ok {
-		return nil, errors.New("LLEN command on non-list item")
+		return []byte(fmt.Sprintf(":%d\r\n\r\n", len(list))), nil
 	}
 
-	return []byte(fmt.Sprintf(":%d\r\n\r\n", len(list))), nil
+	return nil, errors.New("LLEN command on non-list item")
 }
 
 func handleLIndex(ctx context.Context, cmd []string, server utils.Server, conn *net.Conn) ([]byte, error) {

src/modules/list/commands_test.go

@@ -1 +1,96 @@
 package list
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"github.com/echovault/echovault/src/server"
+	"github.com/echovault/echovault/src/utils"
+	"github.com/tidwall/resp"
+	"testing"
+)
+
+func Test_HandleLLEN(t *testing.T) {
+	mockServer := server.NewServer(server.Opts{})
+
+	tests := []struct {
+		preset           bool
+		key              string
+		presetValue      interface{}
+		command          []string
+		expectedResponse interface{}
+		expectedValue    []interface{}
+		expectedError    error
+	}{
+		{ // If key exists and is a list, return the lists length
+			preset:           true,
+			key:              "key1",
+			presetValue:      []interface{}{"value1", "value2", "value3", "value4"},
+			command:          []string{"LLEN", "key1"},
+			expectedResponse: 4,
+			expectedValue:    nil,
+			expectedError:    nil,
+		},
+		{ // If key does not exist, return 0
+			preset:           false,
+			key:              "key2",
+			presetValue:      nil,
+			command:          []string{"LLEN", "key2"},
+			expectedResponse: 0,
+			expectedValue:    nil,
+			expectedError:    nil,
+		},
+		{ // Command too short
+			preset:           false,
+			key:              "key3",
+			presetValue:      nil,
+			command:          []string{"LLEN"},
+			expectedResponse: 0,
+			expectedValue:    nil,
+			expectedError:    errors.New(utils.WRONG_ARGS_RESPONSE),
+		},
+		{ // Command too long
+			preset:           false,
+			key:              "key4",
+			presetValue:      nil,
+			command:          []string{"LLEN", "key4", "key4"},
+			expectedResponse: 0,
+			expectedValue:    nil,
+			expectedError:    errors.New(utils.WRONG_ARGS_RESPONSE),
+		},
+		{ // Trying to get lengths on a non-list returns error
+			preset:           true,
+			key:              "key5",
+			presetValue:      "Default value",
+			command:          []string{"LLEN", "key5"},
+			expectedResponse: 0,
+			expectedValue:    nil,
+			expectedError:    errors.New("LLEN command on non-list item"),
+		},
+	}
+
+	for _, test := range tests {
+		if test.preset {
+			if _, err := mockServer.CreateKeyAndLock(context.Background(), test.key); err != nil {
+				t.Error(err)
+			}
+			mockServer.SetValue(context.Background(), test.key, test.presetValue)
+			mockServer.KeyUnlock(test.key)
+		}
+		res, err := handleLLen(context.Background(), test.command, mockServer, nil)
+		if test.expectedError != nil {
+			if err.Error() != test.expectedError.Error() {
+				t.Errorf("expected error \"%s\", got \"%s\"", test.expectedError.Error(), err.Error())
+			}
+			continue
+		}
+		rd := resp.NewReader(bytes.NewBuffer(res))
+		rv, _, err := rd.ReadValue()
+		if err != nil {
+			t.Error(err)
+		}
+		if rv.Integer() != test.expectedResponse {
+			t.Errorf("expected integer response \"%d\", got \"%d\"", test.expectedResponse, rv.Integer())
+		}
+	}
+}