usememos/memos · error

matches argument must be a string

Error message

matches argument must be a string

What it means

After arity checks, the matches() pattern must be a string literal. getConstValue returns the constant but the type switch only accepts string, so numeric, boolean, or identifier arguments fail with this error before a RegexCondition is built.

Source

Thrown at internal/filter/parser.go:370

	}

	field, ok := schema.Field(targetName)
	if !ok {
		return nil, errors.Errorf("unknown identifier %q", targetName)
	}
	if !field.SupportsContains {
		return nil, errors.Errorf("identifier %q does not support matches()", targetName)
	}
	if len(call.Args) != 1 {
		return nil, errors.New("matches expects exactly one argument")
	}
	value, err := getConstValue(call.Args[0])
	if err != nil {
		return nil, errors.Wrap(err, "matches only supports literal arguments")
	}
	pattern, ok := value.(string)
	if !ok {
		return nil, errors.New("matches argument must be a string")
	}
	return &RegexCondition{
		Field:   targetName,
		Pattern: pattern,
	}, nil
}

func buildValueExpr(expr *exprv1.Expr, pc parseContext) (ValueExpr, error) {
	if identName, err := getIdentName(expr); err == nil {
		// `now` is not a schema field; it folds to the frozen evaluation time.
		if identName == "now" {
			return &LiteralValue{Value: pc.now.Unix()}, nil
		}
		if _, ok := pc.schema.Field(identName); !ok {
			return nil, errors.Errorf("unknown identifier %q", identName)
		}
		return &FieldRef{Name: identName}, nil
	}

View on GitHub (pinned to 14d757ce1f)

Solutions

1. Quote the pattern: content.matches("^[A-Z]")
2. Escape the pattern when embedding it from code (strconv.Quote) to keep it one literal
3. Remember only literal arguments are supported; there is no dynamic pattern binding

Example fix

// before
content.matches(123)

// after
content.matches("123")

// Ensure the pattern slot holds a quoted literal before sending
const ok = /^"(?:[^"\\]|\\.)*"$/.test(patternToken);
if (!ok) throw new Error('matches pattern must be a quoted string literal');

const isQuotedPattern = (p: string): boolean => /^"(?:[^"\\]|\\.)*"$/.test(p);

When it happens

Trigger: content.matches(123), content.matches(someVar), or any matches() call whose sole argument is not a quoted string literal.

Common situations: Interpolating a precompiled pattern object or unquoted variable into the filter string; forgetting that the filter DSL has no variable binding besides schema fields.

Related errors

• text match argument must be a string
• matches requires a target
• matches expects exactly one argument
• timestamp() argument must be an RFC3339 string or epoch int
• duration() argument must be a string

AI-assisted analysis of usememos/memos@14d757ce1f (2026-08-15). Data as JSON: /api/errors/19bbde66be3b0669. Report an issue: GitHub.