flxzt/rnote · error · anyhow::Error

shapestroke is not a JSON object.

Error message

shapestroke is not a JSON object.

What it means

Thrown in TryFrom::<RnoteFileMaj0Min13>::try_from during the maj0min13->maj0min15 migration. When a component's 'value' object contains a 'shapestroke' key, that key must map to a JSON object so its 'shape' field can be located; if 'shapestroke' is a scalar, array, or null-like non-object, migration aborts. It signals malformed shape-stroke data in the file.

Solutions

  1. Inspect the component JSON and make 'shapestroke' an object containing 'shape'.
  2. Re-save the file with the Rnote version that produced it, then retry the migration.
  3. Restore from backup/autosave if the archive is corrupted.
  4. If the component is unusable, replace its 'value' with null so the migration skips it.

Example fix

// before
{"value": {"shapestroke": ["rect"]}}
// after
{"value": {"shapestroke": {"shape": {"rect": {"transform": {"affine": [1,0,0,1,0,0,0,0,1]}}}}}}
Defensive patterns

Strategy: validation

Validate before calling

fn shapestroke_is_object(comp: &serde_json::Value) -> bool {
    comp.get("value")
        .and_then(|v| v.get("shapestroke"))
        .map_or(true, |s| s.is_object())
}

Type guard

fn get_shapestroke<'a>(value: &'a serde_json::Value) -> Option<&'a serde_json::Map<String, serde_json::Value>> {
    value.get("shapestroke").and_then(|s| s.as_object())
}

Try / catch

match RnoteFileMaj0Min15::try_from(file) {
    Ok(f) => open(f),
    Err(e) if e.to_string().contains("shapestroke is not a JSON object") => {
        log::error!("malformed shapestroke payload: {e}");
        restore_from_backup();
    }
    Err(e) => return Err(e),
}

Prevention

When it happens

Trigger: try_from hits a component with value['shapestroke'] present but not a JSON object (e.g. shapestroke: "rect-data" or shapestroke: []).

Common situations: Hand-edited .rnote archives, files damaged by partial writes, or output of a buggy third-party exporter that flattened shapestroke to a non-object.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

AI-assisted analysis of flxzt/rnote@bbc5354502 (2026-09-08). Data as JSON: /api/errors/2316231298a45d5a. Report an issue: GitHub.

Appendix: source

Thrown at crates/rnote-engine/src/fileformats/rnoteformat/maj0min15.rs:47

            .ok_or(anyhow!("stroke components is not a JSON array."))?
            .iter_mut()
        {
            let value = comp
                .as_object_mut()
                .ok_or(anyhow!("stroke component is not a JSON object."))?
                .get_mut("value")
                .ok_or(anyhow!("stroke component does not contain 'value'."))?;
            if value.is_null() {
                continue;
            }
            if let Some(shapestroke) = value
                .as_object_mut()
                .ok_or(anyhow!("value is not a JSON object."))?
                .get_mut("shapestroke")
            {
                let shape = shapestroke
                    .as_object_mut()
                    .ok_or(anyhow!("shapestroke is not a JSON object."))?
                    .get_mut("shape")
                    .ok_or(anyhow!("shapestroke does not contain 'shape'."))?;

                if let Some(rect) = shape
                    .as_object_mut()
                    .ok_or(anyhow!("shape is not a JSON object."))?
                    .get_mut("rect")
                {
                    convert_transform_to_affine_in_obj(rect)?;
                } else if let Some(ellipse) = shape
                    .as_object_mut()
                    .ok_or(anyhow!("shape is not a JSON object."))?
                    .get_mut("ellipse")
                {
                    convert_transform_to_affine_in_obj(ellipse)?;
                }
            } else if let Some(textstroke) = value
                .as_object_mut()

View on GitHub (pinned to bbc5354502)