larksuite/cli · error

L2: field %q has format: binary but type = %q (want string)

Error message

L2: field %q has format: binary but type = %q (want string)

What it means

walkForL2's recursive per-field check: a property declares format: binary (file upload) but its JSON type is not string - binary payloads are transported as strings, so the combination is contradictory.

Source

Thrown at internal/schema/lint.go:123

			errs = append(errs, fmt.Errorf("L3: _meta.access_tokens contains invalid value %q (allowed: user, bot)", t))
		}
	}

	return errs
}

// walkForL2 recursively applies per-field L2 checks (format:binary on
// non-string; minimum>=maximum) plus the sub-object required-exists invariant.
// Required only matters on object-typed Properties (e.g. the params / data
// wrappers); leaf scalars ignore it.
func walkForL2(props *OrderedProps, errs *[]error) {
	if props == nil {
		return
	}
	for _, k := range props.Order {
		p := props.Map[k]
		if p.Format == "binary" && p.Type != "string" {
			*errs = append(*errs, fmt.Errorf("L2: field %q has format: binary but type = %q (want string)", k, p.Type))
		}
		if p.Minimum != nil && p.Maximum != nil && *p.Minimum >= *p.Maximum {
			*errs = append(*errs, fmt.Errorf("L2: field %q minimum (%v) >= maximum (%v)", k, *p.Minimum, *p.Maximum))
		}
		if n := len(p.EnumDescriptions); n > 0 && n != len(p.Enum) {
			*errs = append(*errs, fmt.Errorf("L2: field %q enumDescriptions length (%d) != enum length (%d)", k, n, len(p.Enum)))
		}
		if len(p.Required) > 0 && p.Properties != nil {
			for _, r := range p.Required {
				if _, ok := p.Properties.Map[r]; !ok {
					*errs = append(*errs, fmt.Errorf("L2: required key %q in %q not found in its properties", r, k))
				}
			}
		}
		if p.Properties != nil {
			walkForL2(p.Properties, errs)
		}
	}

View on GitHub (pinned to 7fd6ef3c07)

Solutions

1. Set the property's Type to "string" while keeping Format: "binary"
2. Remove the format:"binary" if the field is not actually binary
3. Fix the code/metadata generator that emitted the wrong type

Example fix

// before
Property{Type: "object", Format: "binary"}
// after
Property{Type: "string", Format: "binary"}

for _, p := range props {
  if p.Format == "binary" && p.Type != "string" {
    return fmt.Errorf("binary field %s must have type string", name)
  }
}

func isBinaryString(p *Property) bool { return p.Format == "binary" && p.Type == "string" }

When it happens

Trigger: walkForL2 visits a properties map where a property p has p.Format == "binary" and p.Type is something else (e.g. "object", "integer", or a typo).

Common situations: Hand-authoring a file-upload parameter and setting type to "file" or "object" instead of "string"; generator bug emitting wrong type for binary fields.

Related errors

• L2: field %q minimum (%v) >= maximum (%v)
• L2: field %q enumDescriptions length (%d) != enum length (%d
• L2: required key %q in %q not found in its properties
• L1: property %q has invalid type %q
• L1: array property %q missing items

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/dc5215b89aea8915. Report an issue: GitHub.