larksuite/cli · error

expected exactly %d items for %s, got %d

Error message

expected exactly %d items for %s, got %d

What it means

For fixed-size array targets (e.g. [2]string tuples used by fixed-arity API params), convertReflectValue enforces exact length and reports 'expected exactly N items for <type>, got M' when the raw list length differs.

Source

Thrown at shortcuts/common/typed_binder.go:218

			return nil, err
		}
		return json.RawMessage(encoded), nil
	}
	if target.Kind() == reflect.Pointer {
		value, err := convertReflectValue(raw, target.Elem())
		if err != nil {
			return nil, err
		}
		pointer := reflect.New(target.Elem())
		pointer.Elem().Set(reflect.ValueOf(value))
		return pointer.Interface(), nil
	}
	if target.Kind() == reflect.Array || target.Kind() == reflect.Slice {
		if rawValue.Kind() != reflect.Array && rawValue.Kind() != reflect.Slice {
			return nil, fmt.Errorf("expected list, got %T", raw)
		}
		if target.Kind() == reflect.Array && rawValue.Len() != target.Len() {
			return nil, fmt.Errorf("expected exactly %d items for %s, got %d", target.Len(), target, rawValue.Len())
		}
		result := reflect.MakeSlice(reflect.SliceOf(target.Elem()), rawValue.Len(), rawValue.Len())
		for i := 0; i < rawValue.Len(); i++ {
			value, err := convertReflectValue(rawValue.Index(i).Interface(), target.Elem())
			if err != nil {
				return nil, err
			}
			result.Index(i).Set(reflect.ValueOf(value))
		}
		if target.Kind() == reflect.Array {
			array := reflect.New(target).Elem()
			reflect.Copy(array, result)
			return array.Interface(), nil
		}
		return result.Convert(target).Interface(), nil
	}
	if rawValue.Type().ConvertibleTo(target) {
		converted := reflect.New(target).Elem()

View on GitHub (pinned to 7fd6ef3c07)

Solutions

1. Count elements against the required length shown in the error's target type (e.g. [2]string)
2. Add missing or remove extra elements to reach the exact count
3. Use null placeholders if the API allows optional tuple slots

Example fix

// before
--range '["2024-01-01"]'
// after
--range '["2024-01-01","2024-12-31"]'

const v = JSON.parse(raw); if (v.length !== 2) throw new Error('exactly 2 items required')

func hasLen(s string, n int) bool { var v []any; if json.Unmarshal([]byte(s), &v) != nil { return false }; return len(v) == n }

if strings.Contains(err.Error(), "expected exactly") { /* parse the required count from the message and pad/trim the input */ }

When it happens

Trigger: Supplying fewer or more elements than the fixed array length, e.g. a 2-element tuple field given '["a"]' or '["a","b","c"]'.

Common situations: API requiring paired values (e.g. [key, value] or [start, end]) where the user passes only one; misunderstanding fixed-arity schema fields.

Related errors

• expected list, got %T
• %v cannot be represented as %s

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/6d08e0ec753b2040. Report an issue: GitHub.