Per-chart export: copy/download spec and PNG/SVG from the preview header

src/core/chart-export.test.ts

@@ -0,0 +1,132 @@
+import { describe, expect, it } from 'vitest';
+import {
+  chartExportFilename,
+  inlineReferencedDatasets,
+  MAX_BASENAME_LEN,
+  referencedDatasetNames,
+  snippetFileBasename,
+} from './chart-export';
+import { DatasetNotFoundError, type ResolvableDataset } from './rendering';
+
+describe('snippetFileBasename', () => {
+  it('keeps the user’s words and case', () => {
+    expect(snippetFileBasename('Sales by Region')).toBe('Sales-by-Region');
+  });
+
+  it('swaps whitespace runs for a single dash', () => {
+    expect(snippetFileBasename('  a   b  c  ')).toBe('a-b-c');
+  });
+
+  it('folds dots into the separator so the extension stays unambiguous', () => {
+    expect(snippetFileBasename('data.v1.final')).toBe('data-v1-final');
+  });
+
+  it('strips characters illegal on Windows / awkward in URLs', () => {
+    expect(snippetFileBasename('a/b\\c:d*e?f"g<h>i|j')).toBe('abcdefghij');
+  });
+
+  it('keeps non-latin letters (no ASCII folding — full-script support)', () => {
+    expect(snippetFileBasename('Продажи по региону')).toBe('Продажи-по-региону');
+    expect(snippetFileBasename('売上 グラフ')).toBe('売上-グラフ');
+  });
+
+  it('collapses and trims dashes', () => {
+    expect(snippetFileBasename('--a -- b--')).toBe('a-b');
+  });
+
+  it('falls back to "chart" when nothing usable remains', () => {
+    expect(snippetFileBasename('')).toBe('chart');
+    expect(snippetFileBasename('   ')).toBe('chart');
+    expect(snippetFileBasename('/// \\\\\\')).toBe('chart');
+    expect(snippetFileBasename('...')).toBe('chart');
+  });
+
+  it('caps the length and never leaves a trailing dash from the cut', () => {
+    const long = snippetFileBasename('x'.repeat(200));
+    expect(long.length).toBe(MAX_BASENAME_LEN);
+    // A name whose cap boundary lands on a dash must not end in one.
+    const dashy = snippetFileBasename('a'.repeat(MAX_BASENAME_LEN - 1) + ' bbbb');
+    expect(dashy.endsWith('-')).toBe(false);
+  });
+
+  it('drops control characters', () => {
+    // Build the control byte from a code point so no literal control char is in source.
+    expect(snippetFileBasename(`a${String.fromCharCode(1)}bcd`)).toBe('abcd');
+  });
+});
+
+describe('chartExportFilename', () => {
+  it('appends the format as the extension', () => {
+    expect(chartExportFilename('Sales by Region', 'png')).toBe('Sales-by-Region.png');
+    expect(chartExportFilename('Sales by Region', 'svg')).toBe('Sales-by-Region.svg');
+    expect(chartExportFilename('Sales by Region', 'vl.json')).toBe('Sales-by-Region.vl.json');
+  });
+
+  it('uses the "chart" fallback for an unusable name', () => {
+    expect(chartExportFilename('', 'png')).toBe('chart.png');
+  });
+});
+
+describe('referencedDatasetNames', () => {
+  it('returns the saved-dataset names a spec references, deduped', () => {
+    const spec = JSON.stringify({
+      layer: [
+        { data: { name: 'sales' } },
+        { data: { name: 'sales' } },
+        { data: { name: 'costs' } },
+      ],
+    });
+    expect(referencedDatasetNames(spec).sort()).toEqual(['costs', 'sales']);
+  });
+
+  it('excludes names the spec defines for itself via top-level datasets', () => {
+    const spec = JSON.stringify({
+      datasets: { local: [{ a: 1 }] },
+      data: { name: 'local' },
+    });
+    expect(referencedDatasetNames(spec)).toEqual([]);
+  });
+
+  it('returns [] for an inline-data spec (no references)', () => {
+    const spec = JSON.stringify({ data: { values: [{ a: 1 }] }, mark: 'bar' });
+    expect(referencedDatasetNames(spec)).toEqual([]);
+  });
+
+  it('returns [] for unparseable text rather than throwing', () => {
+    expect(referencedDatasetNames('{ not json')).toEqual([]);
+  });
+});
+
+describe('inlineReferencedDatasets', () => {
+  const sales: ResolvableDataset = {
+    name: 'sales',
+    data: [{ region: 'N', value: 10 }],
+    format: 'json',
+    source: 'inline',
+  };
+
+  const parse = (text: string) => JSON.parse(text) as { data?: unknown; width?: unknown };
+
+  it('replaces a named reference with the dataset’s inline values', () => {
+    const spec = JSON.stringify({ data: { name: 'sales' }, mark: 'bar' });
+    const out = parse(inlineReferencedDatasets(spec, [sales]));
+    expect(out.data).toEqual({ values: [{ region: 'N', value: 10 }] });
+  });
+
+  it('resolves the name case-insensitively (mirrors reference resolution)', () => {
+    const spec = JSON.stringify({ data: { name: 'Sales' }, mark: 'bar' });
+    const out = parse(inlineReferencedDatasets(spec, [sales]));
+    expect(out.data).toEqual({ values: [{ region: 'N', value: 10 }] });
+  });
+
+  it('leaves sizing as authored — no fit-mode applied', () => {
+    const spec = JSON.stringify({ data: { name: 'sales' }, width: 300, mark: 'bar' });
+    const out = parse(inlineReferencedDatasets(spec, [sales]));
+    expect(out.width).toBe(300);
+  });
+
+  it('throws DatasetNotFoundError when a referenced dataset is missing', () => {
+    const spec = JSON.stringify({ data: { name: 'missing' }, mark: 'bar' });
+    expect(() => inlineReferencedDatasets(spec, [sales])).toThrow(DatasetNotFoundError);
+  });
+});