diff --git a/CHANGELOG.md b/CHANGELOG.md
index a3da84f..8d2b63b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,25 @@ All notable changes to this project will be documented in this file. Dates are d
 
 Generated by [`auto-changelog`](https://github.com/CookPete/auto-changelog).
 
+### [14.0.4](https://github.com/eea/volto-plotlycharts/compare/14.0.3...14.0.4) - 25 May 2026
+
+#### :rocket: New Features
+
+- feat(PlotlyComponent): structure figure-info for indexing + embed LLM summary [Miu Razvan - [`0790ba3`](https://github.com/eea/volto-plotlycharts/commit/0790ba3abb17be707d4b7bcf1102ff3db28752b7)]
+
+#### :bug: Bug Fixes
+
+- fix: embed data table only includes columns used by chart traces [Miu Razvan - [`3086bb5`](https://github.com/eea/volto-plotlycharts/commit/3086bb5ecd0f295f48539d293fb9d77efee39254)]
+
+#### :house: Internal changes
+
+- style: Automated code fix [eea-jenkins - [`bf22b4a`](https://github.com/eea/volto-plotlycharts/commit/bf22b4af2f6a359c510cd6a8330de3282758b5bb)]
+
+#### :hammer_and_wrench: Others
+
+- Add unit tests [Miu Razvan - [`d9385aa`](https://github.com/eea/volto-plotlycharts/commit/d9385aa94dd090ed50dad69f73f65b4c8e597c9b)]
+- remove unnused variable [Miu Razvan - [`27b484a`](https://github.com/eea/volto-plotlycharts/commit/27b484a5c7278e26f2d31a057ab115d6d1f60343)]
+- Pin @plone/scripts to 3.x [Miu Razvan - [`db5bdb8`](https://github.com/eea/volto-plotlycharts/commit/db5bdb8e3635be352b5c72fe9a902df2bd5228b3)]
 ### [14.0.3](https://github.com/eea/volto-plotlycharts/compare/14.0.2...14.0.3) - 22 April 2026
 
 #### :hammer_and_wrench: Others
diff --git a/package.json b/package.json
index fa04d3d..10e8058 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@eeacms/volto-plotlycharts",
-  "version": "14.0.3",
+  "version": "14.0.4",
   "description": "Plotly Charts and Editor integration for Volto",
   "main": "src/index.js",
   "author": "European Environment Agency: IDM2 A-Team",
@@ -29,7 +29,7 @@
     "@eeacms/volto-datablocks": "*",
     "@eeacms/volto-embed": "*",
     "@eeacms/volto-matomo": "*",
-    "@plone/scripts": "*",
+    "@plone/scripts": "^3.10.6",
     "handsontable": "^15.2.0",
     "jsoneditor": "10.2.0",
     "jszip": "3.10.1",
@@ -39,7 +39,7 @@
   },
   "devDependencies": {
     "@cypress/code-coverage": "^3.10.0",
-    "@plone/scripts": "*",
+    "@plone/scripts": "^3.10.6",
     "babel-plugin-transform-class-properties": "^6.24.1",
     "cypress": "13.1.0",
     "dotenv": "^16.3.2",
diff --git a/src/PlotlyComponent/PlotlyComponent.jsx b/src/PlotlyComponent/PlotlyComponent.jsx
index 7efb37d..73704b8 100644
--- a/src/PlotlyComponent/PlotlyComponent.jsx
+++ b/src/PlotlyComponent/PlotlyComponent.jsx
@@ -1,38 +1,38 @@
-import { useMemo, useRef, useEffect, useState, useCallback } from 'react';
-import { useIntl } from 'react-intl';
-import { compose } from 'redux';
-import { connect } from 'react-redux';
-import isArray from 'lodash/isArray';
-import uniqBy from 'lodash/uniqBy';
-import sortBy from 'lodash/sortBy';
-import isNil from 'lodash/isNil';
-import debounce from 'lodash/debounce';
-import cx from 'classnames';
-import { FormField } from 'semantic-ui-react';
 // import { constants } from '@eeacms/react-chart-editor';
-import { injectLazyLibs } from '@plone/volto/helpers/Loadable/Loadable';
-import { flattenToAppURL } from '@plone/volto/helpers/Url/Url';
 import { VisibilitySensor } from '@eeacms/volto-datablocks/components';
 import { connectToProviderData } from '@eeacms/volto-datablocks/hocs';
-import { connectBlockToVisualization } from '@eeacms/volto-plotlycharts/hocs';
+import { Toolbar } from '@eeacms/volto-plotlycharts/Utils';
+import {
+  getMetadataFlags,
+  processMetadataArrays,
+} from '@eeacms/volto-plotlycharts/Utils/utils';
 import {
   deleteGeneratedFigureMetadataBlock,
-  getFigurePosition,
   getFigureMetadata,
+  getFigurePosition,
   insertFigureMetadataBeforeBlock,
 } from '@eeacms/volto-plotlycharts/helpers';
 import {
-  updateTrace,
   updateDataSources,
+  updateTrace,
 } from '@eeacms/volto-plotlycharts/helpers/plotly';
 import { applyFilters } from '@eeacms/volto-plotlycharts/helpers/transforms';
-import { Toolbar } from '@eeacms/volto-plotlycharts/Utils';
-import Plot from './Plot';
+import { connectBlockToVisualization } from '@eeacms/volto-plotlycharts/hocs';
+import { injectLazyLibs } from '@plone/volto/helpers/Loadable/Loadable';
+import { flattenToAppURL } from '@plone/volto/helpers/Url/Url';
+import cx from 'classnames';
+import debounce from 'lodash/debounce';
+import isArray from 'lodash/isArray';
+import isNil from 'lodash/isNil';
+import sortBy from 'lodash/sortBy';
+import uniqBy from 'lodash/uniqBy';
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
+import { useIntl } from 'react-intl';
+import { connect } from 'react-redux';
+import { compose } from 'redux';
+import { FormField } from 'semantic-ui-react';
 import Placeholder from './Placeholder';
-import {
-  getMetadataFlags,
-  processMetadataArrays,
-} from '@eeacms/volto-plotlycharts/Utils/utils';
+import Plot from './Plot';
 
 // generateCSVForDataset,
 // generateOriginalCSV,
@@ -58,6 +58,11 @@ function stripHtml(html) {
   return doc.body.textContent || '';
 }
 
+// Only null/undefined/blank strings are empty. `0` and `false` are real data.
+function isEmptyValue(value) {
+  return isNil(value) || (typeof value === 'string' && value.trim() === '');
+}
+
 function UnconnectedPlotlyComponent(props) {
   const intl = useIntl();
   const { reactChartEditor } = props;
@@ -82,12 +87,7 @@ function UnconnectedPlotlyComponent(props) {
     onDeleteBlock,
     blocksConfig,
   } = props;
-  const {
-    height,
-    vis_url,
-    with_metadata_section = true,
-    llm_summary,
-  } = props.data;
+  const { height, vis_url, with_metadata_section = true } = props.data;
   const [initialized, setInitialized] = useState(false);
   const [filtersState, setFiltersState] = useState([]);
   const [autoscaleHeight, setAutoscaleHeight] = useState(null);
@@ -446,65 +446,89 @@ function UnconnectedPlotlyComponent(props) {
         data={toolbarData}
         provider_metadata={provider_metadata}
       />
-
-      {llm_summary && (
-        <div
-          className="llm-summary"
-          style={{ display: 'none' }}
-          aria-hidden="true"
-        >
-          {llm_summary}
-        </div>
-      )}
     </div>
   );
 }
 
-function prepareEmbedData(dataSources, provider_metadata, core_metadata) {
-  let array = [];
+function prepareEmbedData(
+  dataSources,
+  traces,
+  provider_metadata,
+  core_metadata,
+) {
+  const array = [];
+  const srcKeys = traces.reduce((acc, trace) => {
+    Object.keys(trace).forEach((key) => {
+      if (key.endsWith('src')) {
+        if (!acc.includes(trace[key])) {
+          acc.push(trace[key]);
+        }
+      }
+    });
+    return acc;
+  }, []);
   Object.entries(dataSources).forEach(([key, items]) => {
+    if (!srcKeys.includes(key)) return;
     items.forEach((item, index) => {
       if (!array[index]) array[index] = {};
       array[index][key] = item;
     });
   });
 
-  let readme = provider_metadata?.readme ? [provider_metadata?.readme] : [];
+  const readme = provider_metadata?.readme ? [provider_metadata?.readme] : [];
   const metadataFlags = getMetadataFlags(core_metadata);
   const metadataArrays = processMetadataArrays(core_metadata, metadataFlags);
 
-  return { array, readme, metadataArrays, metadataFlags };
+  return { array, readme, metadataArrays };
 }
 
-function Table({ rows }) {
-  const stableKeys = Object.keys(rows?.[0] || {});
+// Column-major rendering: one line per column, values comma-joined in their
+// original row order so positional meaning is preserved. Blank cells become "-",
+// fully-empty columns are dropped. Generic — also used for metadata tables.
+function Table({ rows, title }) {
+  if (!isArray(rows) || rows.length === 0) return null;
+
+  // Union of keys across all rows, preserving first-appearance order.
+  const keys = rows.reduce((acc, row) => {
+    Object.keys(row || {}).forEach((key) => {
+      if (!acc.includes(key)) acc.push(key);
+    });
+    return acc;
+  }, []);
+
+  const columns = keys
+    .map((key) => {
+      const values = rows.map((row) =>
+        isEmptyValue(row?.[key]) ? '-' : String(row[key]),
+      );
+      // Drop columns that carry no data at all.
+      if (values.every((value) => value === '-')) return null;
+      return { key, text: values.join(', ') };
+    })
+    .filter(Boolean);
+
+  // No renderable column -> render nothing, including the heading. This keeps
+  // the heading and its content as a single visibility decision.
+  if (columns.length === 0) return null;
 
   return (
-    <table className="embed-data-table">
-      <thead>
-        <tr>
-          {stableKeys.map((key) => (
-            <th key={key}>{key}</th>
-          ))}
-        </tr>
-      </thead>
-      <tbody>
-        {rows.map((row, index) => (
-          <tr key={index}>
-            {stableKeys.map((key) => (
-              <td key={key}>{row[key]}</td>
-            ))}
-          </tr>
+    <>
+      {title && <p>{title}:</p>}
+      <ul className="embed-data-table embed-data-list">
+        {columns.map((column) => (
+          <li key={column.key}>
+            {column.key}: {column.text}
+          </li>
         ))}
-      </tbody>
-    </table>
+      </ul>
+    </>
   );
 }
 
 function EmbedData(props) {
-  const { provider_metadata, content, block } = props; // reactChartEditorLib,
+  const { provider_metadata, block } = props; // reactChartEditorLib,
   const visualization = props.data?.visualization || {};
-  const { dataSources = {}, layout } = visualization;
+  const { dataSources = {}, layout, data: traces = [] } = visualization;
 
   const {
     data_provenance,
@@ -524,65 +548,71 @@ function EmbedData(props) {
 
   const embedData = prepareEmbedData(
     dataSources,
+    traces,
     provider_metadata,
     core_metadata,
   );
-  const { array, readme, metadataArrays, metadataFlags } = embedData;
+  const { array, readme, metadataArrays } = embedData;
+
+  const subtitle = stripHtml(layout?.title?.subtitle?.text || '');
+  const llmSummary = stripHtml(props.data?.llm_summary || '');
 
   return (
     <div
-      className="figure-data-table"
+      className="figure-info"
       data-for-chart-id={block}
       style={{ display: 'none' }}
     >
-      <h3 className="page-title">{content.title}</h3>
       {!!layout?.title?.text && (
-        <h4 className="chart-title">{stripHtml(layout.title.text)}</h4>
+        <p className="chart-title">
+          Visualization title: {stripHtml(layout.title.text)}
+        </p>
       )}
-      {!!layout?.title?.subtitle?.text && (
-        <h4 className="chart-sub-title">
-          {stripHtml(layout.title.subtitle.text)}
-        </h4>
+      {!!subtitle && subtitle !== layout?.yaxis?.title?.text && (
+        <p className="chart-sub-title">
+          {layout?.yaxis?.title?.text
+            ? 'Subtitle: '
+            : 'Secondary label (shown as chart subtitle; may also serve as the y-axis title): '}
+          {subtitle}
+        </p>
       )}
+      {!!llmSummary && <p className="llm-summary">Summary: {llmSummary}</p>}
       {!!layout?.xaxis?.title?.text && (
-        <p className="x-axis-label">{stripHtml(layout.xaxis.title.text)}</p>
+        <p className="x-axis-label">
+          X axis title: {stripHtml(layout.xaxis.title.text)}
+        </p>
       )}
       {!!layout?.yaxis?.title?.text && (
-        <p className="y-axis-label">{stripHtml(layout.yaxis.title.text)}</p>
+        <p className="y-axis-label">
+          Y axis title: {stripHtml(layout.yaxis.title.text)}
+        </p>
       )}
 
-      <Table rows={array} />
+      <p className="data-reading-note">
+        In each data section below, every line is one column: its values are
+        listed in row order and align by position across columns — the Nth value
+        in every column belongs to the same record. "-" means no value.
+      </p>
 
-      {metadataFlags.hasDataProvenance && (
-        <>
-          <h4>Data Provenance</h4>
-          <Table rows={metadataArrays.data_provenance_array} />
-        </>
-      )}
-      {metadataFlags.hasOtherOrganisation && (
-        <>
-          <h4>Other Organisations</h4>
-          <Table rows={metadataArrays.other_organisation_array} />
-        </>
-      )}
-      {metadataFlags.hasTemporalCoverage && (
-        <>
-          <h4>Temporal Coverage</h4>
-          <Table rows={metadataArrays.temporal_coverage_array} />
-        </>
-      )}
-      {metadataFlags.hasGeoCoverage && (
-        <>
-          <h4>Geographical Coverage</h4>
-          <Table rows={metadataArrays.geo_coverage_array} />
-        </>
-      )}
-      {metadataFlags.hasPublisher && (
-        <>
-          <h4>Publisher</h4>
-          <Table rows={metadataArrays.publisher_array} />
-        </>
-      )}
+      <Table title="Data" rows={array} />
+
+      <Table
+        title="Data Provenance"
+        rows={metadataArrays.data_provenance_array}
+      />
+      <Table
+        title="Other Organisations"
+        rows={metadataArrays.other_organisation_array}
+      />
+      <Table
+        title="Temporal Coverage"
+        rows={metadataArrays.temporal_coverage_array}
+      />
+      <Table
+        title="Geographical Coverage"
+        rows={metadataArrays.geo_coverage_array}
+      />
+      <Table title="Publisher" rows={metadataArrays.publisher_array} />
 
       <div>{readme}</div>
     </div>
diff --git a/src/Utils/utils.test.js b/src/Utils/utils.test.js
new file mode 100644
index 0000000..cd98e07
--- /dev/null
+++ b/src/Utils/utils.test.js
@@ -0,0 +1,189 @@
+import {
+  generateFinalCSV,
+  generateOriginalCSV,
+  getMetadataFlags,
+  processMetadataArrays,
+  generateCSVForDataset,
+} from './utils';
+
+jest.mock('@eeacms/volto-matomo/utils', () => ({
+  trackLink: jest.fn(),
+}));
+
+const emptyCoreMetadata = {};
+
+describe('getMetadataFlags', () => {
+  it('should be all false for empty metadata', () => {
+    expect(getMetadataFlags(emptyCoreMetadata)).toEqual({
+      hasDataProvenance: false,
+      hasOtherOrganisation: false,
+      hasTemporalCoverage: false,
+      hasGeoCoverage: false,
+      hasPublisher: false,
+    });
+  });
+
+  it('should flag present metadata sections', () => {
+    expect(
+      getMetadataFlags({
+        data_provenance: ['Source A'],
+        publisher: ['EEA'],
+      }),
+    ).toMatchObject({
+      hasDataProvenance: true,
+      hasPublisher: true,
+      hasOtherOrganisation: false,
+    });
+  });
+});
+
+describe('processMetadataArrays', () => {
+  it('should return empty arrays when no flag is set', () => {
+    const flags = getMetadataFlags(emptyCoreMetadata);
+    expect(processMetadataArrays(emptyCoreMetadata, flags)).toEqual({
+      data_provenance_array: [],
+      other_organisation_array: [],
+      temporal_coverage_array: [],
+      geo_coverage_array: [],
+      publisher_array: [],
+    });
+  });
+
+  it('should populate arrays for flagged sections', () => {
+    const core_metadata = {
+      data_provenance: ['Source A', 'Source B'],
+    };
+    const flags = getMetadataFlags(core_metadata);
+    const result = processMetadataArrays(core_metadata, flags);
+
+    expect(result.data_provenance_array.length).toBeGreaterThan(0);
+    // each entry keyed by a column that includes "data_provenance" or "Sources"
+    result.data_provenance_array.forEach((row) => {
+      Object.keys(row).forEach((key) => {
+        expect(key.includes('data_provenance') || key.includes('Sources')).toBe(
+          true,
+        );
+      });
+    });
+  });
+});
+
+describe('generateFinalCSV', () => {
+  it('should concatenate the download source line and data with no metadata', () => {
+    const flags = getMetadataFlags(emptyCoreMetadata);
+    const arrays = processMetadataArrays(emptyCoreMetadata, flags);
+
+    const csv = generateFinalCSV(
+      [{ region: 'EU', value: 10 }],
+      [],
+      flags,
+      arrays,
+      'http://example.org',
+    );
+
+    expect(csv).toContain('Downloaded from: ');
+    expect(csv).toContain('http://example.org');
+    expect(csv).toContain('region,value');
+    expect(csv).toContain('EU');
+  });
+
+  it('should include metadata sections when flags are set', () => {
+    const core_metadata = { publisher: ['EEA'] };
+    const flags = getMetadataFlags(core_metadata);
+    const arrays = processMetadataArrays(core_metadata, flags);
+
+    const csv = generateFinalCSV(
+      [{ region: 'EU', value: 10 }],
+      [],
+      flags,
+      arrays,
+      'http://example.org',
+    );
+
+    expect(csv).toContain('EEA');
+  });
+});
+
+describe('generateOriginalCSV', () => {
+  it('should build CSV from data sources without columns', () => {
+    const csv = generateOriginalCSV(
+      { region: ['EU', 'US'], value: [10, 20] },
+      [],
+      {},
+      'http://example.org',
+      emptyCoreMetadata,
+    );
+
+    expect(csv).toContain('region,value');
+    expect(csv).toContain('EU');
+    expect(csv).toContain('US');
+  });
+
+  it('should order columns according to the provided columns list', () => {
+    const csv = generateOriginalCSV(
+      { value: [10], region: ['EU'] },
+      ['region', 'value'],
+      {},
+      'http://example.org',
+      emptyCoreMetadata,
+    );
+
+    expect(csv).toContain('region,value');
+  });
+
+  it('should prepend the readme from provider metadata', () => {
+    const csv = generateOriginalCSV(
+      { region: ['EU'] },
+      [],
+      { readme: 'Read this' },
+      'http://example.org',
+      emptyCoreMetadata,
+    );
+
+    expect(csv).toContain('Read this');
+  });
+});
+
+describe('generateCSVForDataset', () => {
+  const reactChartEditorLib = {
+    constants: { TRACE_SRC_ATTRIBUTES: ['x', 'y'] },
+    getAttrsPath: (trace) => {
+      const attrs = {};
+      if (trace.x) attrs.x = trace.x;
+      if (trace.y) attrs.y = trace.y;
+      return attrs;
+    },
+    getSrcAttr: (trace, attr) => ({ value: trace[`${attr}src`] }),
+  };
+
+  it('should build CSV from trace-processed data', () => {
+    const csv = generateCSVForDataset(
+      { year: [2020, 2021], region: ['EU', 'US'] },
+      {
+        data: [{ x: [2020, 2021], xsrc: 'year' }],
+        layout: {},
+      },
+      {},
+      emptyCoreMetadata,
+      'http://example.org',
+      reactChartEditorLib,
+    );
+
+    expect(csv).toContain('year');
+    expect(csv).toContain('2020');
+  });
+
+  it('should fall back to data sources when traces yield no data', () => {
+    const csv = generateCSVForDataset(
+      { region: ['EU', 'US'], value: [10, 20] },
+      { data: [], layout: {} },
+      {},
+      emptyCoreMetadata,
+      'http://example.org',
+      reactChartEditorLib,
+    );
+
+    expect(csv).toContain('region,value');
+    expect(csv).toContain('EU');
+  });
+});
diff --git a/src/actions.test.js b/src/actions.test.js
new file mode 100644
index 0000000..f40d095
--- /dev/null
+++ b/src/actions.test.js
@@ -0,0 +1,26 @@
+import { getVisualization, removeVisualization } from './actions';
+import { GET_VISUALIZATION, REMOVE_VISUALIZATION } from './constants';
+
+describe('actions', () => {
+  describe('getVisualization', () => {
+    it('should build a GET_VISUALIZATION request action', () => {
+      expect(getVisualization('/path/to/chart')).toEqual({
+        type: GET_VISUALIZATION,
+        path: '/path/to/chart',
+        request: {
+          op: 'get',
+          path: '/path/to/chart/@visualization',
+        },
+      });
+    });
+  });
+
+  describe('removeVisualization', () => {
+    it('should build a REMOVE_VISUALIZATION action', () => {
+      expect(removeVisualization('/path/to/chart')).toEqual({
+        type: REMOVE_VISUALIZATION,
+        path: '/path/to/chart',
+      });
+    });
+  });
+});
diff --git a/src/helpers/editor.test.js b/src/helpers/editor.test.js
new file mode 100644
index 0000000..ec57806
--- /dev/null
+++ b/src/helpers/editor.test.js
@@ -0,0 +1,60 @@
+import { destroyEditor, onPasteEditor, validateEditor } from './editor';
+
+jest.mock('react-toastify', () => ({
+  toast: { warn: jest.fn() },
+}));
+
+jest.mock('@plone/volto/components/manage/Toast/Toast', () => () => null);
+
+describe('editor helpers', () => {
+  describe('destroyEditor', () => {
+    it('should call destroy on a provided editor', () => {
+      const editor = { destroy: jest.fn() };
+      destroyEditor(editor);
+      expect(editor.destroy).toHaveBeenCalled();
+    });
+
+    it('should do nothing when no editor is given', () => {
+      expect(() => destroyEditor(null)).not.toThrow();
+    });
+  });
+
+  describe('onPasteEditor', () => {
+    it('should repair and format the editor', () => {
+      const editor = {
+        current: { repair: jest.fn(), format: jest.fn() },
+      };
+      onPasteEditor(editor);
+      expect(editor.current.repair).toHaveBeenCalled();
+      expect(editor.current.format).toHaveBeenCalled();
+    });
+
+    it('should swallow errors thrown while repairing', () => {
+      const editor = {
+        current: {
+          repair: () => {
+            throw new Error('bad');
+          },
+          format: jest.fn(),
+        },
+      };
+      expect(() => onPasteEditor(editor)).not.toThrow();
+    });
+  });
+
+  describe('validateEditor', () => {
+    it('should return true when there are no validation errors', async () => {
+      const editor = { current: { validate: jest.fn().mockResolvedValue([]) } };
+      await expect(validateEditor(editor)).resolves.toBe(true);
+    });
+
+    it('should warn and return false when validation errors exist', async () => {
+      const { toast } = require('react-toastify');
+      const editor = {
+        current: { validate: jest.fn().mockResolvedValue([{ message: 'x' }]) },
+      };
+      await expect(validateEditor(editor)).resolves.toBe(false);
+      expect(toast.warn).toHaveBeenCalled();
+    });
+  });
+});
diff --git a/src/middlewares/data_visualizations.test.js b/src/middlewares/data_visualizations.test.js
new file mode 100644
index 0000000..392b6f9
--- /dev/null
+++ b/src/middlewares/data_visualizations.test.js
@@ -0,0 +1,58 @@
+import { data_visualizations } from './data_visualizations';
+import { GET_VISUALIZATION } from '@eeacms/volto-plotlycharts/constants';
+
+const runMiddleware = (action, state) => {
+  const dispatch = jest.fn();
+  const next = jest.fn((a) => a);
+  const store = {
+    getState: () => state,
+    dispatch,
+  };
+  const [mw] = data_visualizations([]);
+  const result = mw(store)(next)(action);
+  return { dispatch, next, result };
+};
+
+describe('data_visualizations middleware', () => {
+  it('should append the provided middlewares', () => {
+    const extra = () => {};
+    const chain = data_visualizations([extra]);
+    expect(chain).toHaveLength(2);
+    expect(chain[1]).toBe(extra);
+  });
+
+  it('should dispatch a PENDING action and forward when not already pending', () => {
+    const { dispatch, next } = runMiddleware(
+      { type: GET_VISUALIZATION, path: '/chart' },
+      { data_visualizations: { pendingVisualizations: {} } },
+    );
+
+    expect(dispatch).toHaveBeenCalledWith({
+      type: `${GET_VISUALIZATION}_PENDING`,
+      path: '/chart',
+    });
+    expect(next).toHaveBeenCalled();
+  });
+
+  it('should short-circuit when the path is already pending', () => {
+    const { dispatch, next, result } = runMiddleware(
+      { type: GET_VISUALIZATION, path: '/chart' },
+      { data_visualizations: { pendingVisualizations: { '/chart': true } } },
+    );
+
+    expect(dispatch).not.toHaveBeenCalled();
+    expect(next).not.toHaveBeenCalled();
+    expect(result).toBeUndefined();
+  });
+
+  it('should forward unrelated actions untouched', () => {
+    const action = { type: 'SOMETHING_ELSE' };
+    const { dispatch, next, result } = runMiddleware(action, {
+      data_visualizations: { pendingVisualizations: {} },
+    });
+
+    expect(dispatch).not.toHaveBeenCalled();
+    expect(next).toHaveBeenCalledWith(action);
+    expect(result).toBe(action);
+  });
+});
diff --git a/src/reducers/data_visualizations.test.js b/src/reducers/data_visualizations.test.js
new file mode 100644
index 0000000..feb1b24
--- /dev/null
+++ b/src/reducers/data_visualizations.test.js
@@ -0,0 +1,108 @@
+import data_visualizations from './data_visualizations';
+import {
+  GET_VISUALIZATION,
+  REMOVE_VISUALIZATION,
+} from '@eeacms/volto-plotlycharts/constants';
+
+const initialState = {
+  data: {},
+  error: null,
+  loaded: false,
+  loading: false,
+  pendingVisualizations: {},
+  failedVisualizations: {},
+  requested: [],
+};
+
+describe('data_visualizations reducer', () => {
+  it('should return the initial state by default', () => {
+    expect(data_visualizations(undefined, {})).toEqual(initialState);
+  });
+
+  it('should mark a path pending on GET_VISUALIZATION_PENDING', () => {
+    const state = data_visualizations(undefined, {
+      type: `${GET_VISUALIZATION}_PENDING`,
+      path: '/chart/@visualization',
+    });
+
+    expect(state.loading).toBe(true);
+    expect(state.loaded).toBe(false);
+    expect(state.error).toBe(null);
+    expect(state.requested).toEqual(['/chart']);
+    expect(state.pendingVisualizations).toEqual({ '/chart': true });
+  });
+
+  it('should clear a failed flag when a pending request restarts', () => {
+    const prev = {
+      ...initialState,
+      failedVisualizations: { '/chart': true },
+    };
+    const state = data_visualizations(prev, {
+      type: `${GET_VISUALIZATION}_PENDING`,
+      path: '/chart/@visualization',
+    });
+
+    expect(state.failedVisualizations).toEqual({});
+  });
+
+  it('should store the result on GET_VISUALIZATION_SUCCESS', () => {
+    const prev = {
+      ...initialState,
+      requested: ['/chart'],
+      pendingVisualizations: { '/chart': true },
+    };
+    const state = data_visualizations(prev, {
+      type: `${GET_VISUALIZATION}_SUCCESS`,
+      path: '/chart/@visualization',
+      result: { foo: 'bar' },
+    });
+
+    expect(state.loaded).toBe(true);
+    expect(state.loading).toBe(false);
+    expect(state.data).toEqual({ '/chart': { foo: 'bar' } });
+    expect(state.requested).toEqual([]);
+    expect(state.pendingVisualizations).toEqual({});
+  });
+
+  it('should record the error and failed flag on GET_VISUALIZATION_FAIL', () => {
+    const prev = {
+      ...initialState,
+      requested: ['/chart'],
+      pendingVisualizations: { '/chart': true },
+    };
+    const state = data_visualizations(prev, {
+      type: `${GET_VISUALIZATION}_FAIL`,
+      path: '/chart/@visualization',
+      error: 'boom',
+    });
+
+    expect(state.error).toBe('boom');
+    expect(state.loaded).toBe(false);
+    expect(state.loading).toBe(false);
+    expect(state.requested).toEqual([]);
+    expect(state.pendingVisualizations).toEqual({});
+    expect(state.failedVisualizations).toEqual({ '/chart': true });
+  });
+
+  it('should drop stored data on REMOVE_VISUALIZATION', () => {
+    const prev = {
+      ...initialState,
+      data: { '/chart': { foo: 'bar' }, '/other': { baz: 1 } },
+    };
+    const state = data_visualizations(prev, {
+      type: REMOVE_VISUALIZATION,
+      path: '/chart',
+    });
+
+    expect(state.data).toEqual({ '/other': { baz: 1 } });
+  });
+
+  it('should handle actions without a path', () => {
+    const state = data_visualizations(undefined, {
+      type: `${GET_VISUALIZATION}_PENDING`,
+    });
+
+    expect(state.requested).toEqual([undefined]);
+    expect(state.pendingVisualizations).toEqual({ undefined: true });
+  });
+});