gastownhall/beads · error

encoding TOML: %w

Error message

encoding TOML: %w

What it means

formulaToTOML encodes the parsed raw structure to TOML using a toml.Encoder with empty indentation. If the value cannot be represented in TOML (e.g. unsupported types after JSON decoding, keys that are invalid, or nil-typed values the encoder rejects), the error is wrapped as 'encoding TOML: %w'. This happens after JSON parsing succeeds, during the actual TOML serialization step.

Source

Thrown at cmd/bd/formula.go:692

	if err != nil {
		return nil, fmt.Errorf("reading source: %w", err)
	}

	// Parse into a map to preserve structure
	var raw map[string]interface{}
	if err := json.Unmarshal(jsonData, &raw); err != nil {
		return nil, fmt.Errorf("parsing JSON: %w", err)
	}

	// Fix float64 to int for known integer fields
	fixIntegerFields(raw)

	// Encode to TOML
	var buf bytes.Buffer
	encoder := toml.NewEncoder(&buf)
	encoder.Indent = ""
	if err := encoder.Encode(raw); err != nil {
		return nil, fmt.Errorf("encoding TOML: %w", err)
	}

	// Post-process to convert escaped \n in strings to multi-line strings
	result := convertToMultiLineStrings(buf.String())

	return []byte(result), nil
}

// convertToMultiLineStrings post-processes TOML to use multi-line strings
// where strings contain newlines. This improves readability for descriptions.
func convertToMultiLineStrings(input string) string {
	// Regular expression to match key = "value with \n"
	// We look for description fields specifically as those benefit most
	lines := strings.Split(input, "\n")
	var result []string

	for _, line := range lines {
		// Check if this line has a string with escaped newlines

View on GitHub (pinned to 71377f2769)

Solutions

1. Normalize the formula JSON: make arrays homogeneous (all strings or all objects) and remove nulls from arrays.
2. Fix integer/float fields so fixIntegerFields and the encoder see consistent types.
3. Update or regenerate the formula to conform to the current schema, then retry conversion.
4. If the TOML library reports a specific key/value, edit just that field in the source JSON.

Example fix

// before
{ "tags": ["a", 1, null] }   // mixed-type array, not TOML-encodable
// after
{ "tags": ["a", "1"] }

// ensure arrays are homogeneous before conversion
for _, v := range raw["tags"].([]interface{}) {
    if _, ok := v.(string); !ok { return errors.New("tags must be all strings") }
}

if _, err := formulaToTOML(f); err != nil {
    if strings.Contains(err.Error(), "encoding TOML") {
        // inspect wrapped toml error; normalize mixed-type arrays/nulls in source JSON
    }
}

When it happens

Trigger: Converting a formula whose raw JSON contains values that cannot map to TOML, such as mixed-type arrays ([1, "a"]), nulls in arrays, deeply unusual structures, or map keys the TOML encoder cannot serialize.

Common situations: Formulas with heterogeneous arrays (JSON allows, TOML does not); null values inside arrays; hand-authored JSON exploiting JSON features with no TOML equivalent; older formula schemas with structures the converter's fixIntegerFields doesn't normalize.

Related errors

• formula has no source path
• parse %s: %w
• toml: %w
• failed to marshal backup state: %w
• parsing formula: %w

AI-assisted analysis of gastownhall/beads@71377f2769 (2026-08-30). Data as JSON: /api/errors/cbcae76a51eeaea1. Report an issue: GitHub.