Add SchemaPresetsAndDefault check

.changeset/schema-presets-and-default.md

@@ -0,0 +1,8 @@
+---
+'@shopify/theme-check-common': minor
+'@shopify/theme-check-node': minor
+---
+
+Add `SchemaPresetsAndDefault` check
+
+Reports section schemas that define both `presets` and `default`, matching the platform validation that rejects them with `Invalid schema: cannot define both 'default' and 'presets'`.

packages/theme-check-common/src/checks/index.ts

@@ -34,6 +34,7 @@ import { MissingTemplate } from './missing-template';
 import { OrphanedSnippet } from './orphaned-snippet';
 import { PaginationSize } from './pagination-size';
 import { ParserBlockingScript } from './parser-blocking-script';
+import { SchemaPresetsAndDefault } from './schema-presets-and-default';
 import { SchemaPresetsBlockOrder } from './schema-presets-block-order';
 import { SchemaPresetsStaticBlocks } from './schema-presets-static-blocks';
 import { RemoteAsset } from './remote-asset';
@@ -128,6 +129,7 @@ export const allChecks: (LiquidCheckDefinition | JSONCheckDefinition)[] = [
   OrphanedSnippet,
   PaginationSize,
   ParserBlockingScript,
+  SchemaPresetsAndDefault,
   SchemaPresetsBlockOrder,
   SchemaPresetsStaticBlocks,
   RemoteAsset,

packages/theme-check-common/src/checks/schema-presets-and-default/index.spec.ts

@@ -0,0 +1,84 @@
+import { expect, describe, it } from 'vitest';
+import { highlightedOffenses, runLiquidCheck } from '../../test';
+import { SchemaPresetsAndDefault } from './index';
+
+const DEFAULT_FILE_NAME = 'sections/file.liquid';
+
+describe('Module: SchemaPresetsAndDefault', () => {
+  it('reports an error when a section defines both presets and default', async () => {
+    const sourceCode = `
+      {% schema %}
+      {
+        "name": "Test section",
+        "presets": [{ "name": "Preset 1" }],
+        "default": { "settings": {} }
+      }
+      {% endschema %}`;
+
+    const offenses = await runLiquidCheck(SchemaPresetsAndDefault, sourceCode, DEFAULT_FILE_NAME);
+    expect(offenses).toHaveLength(1);
+    expect(offenses[0].message).toEqual(
+      "Invalid schema: cannot define both 'default' and 'presets'",
+    );
+
+    const highlights = highlightedOffenses({ [DEFAULT_FILE_NAME]: sourceCode }, offenses);
+    expect(highlights).toEqual(['{ "settings": {} }']);
+  });
+
+  it('reports an error when presets is an empty array', async () => {
+    const sourceCode = `
+      {% schema %}
+      {
+        "name": "Test section",
+        "presets": [],
+        "default": {}
+      }
+      {% endschema %}`;
+
+    const offenses = await runLiquidCheck(SchemaPresetsAndDefault, sourceCode, DEFAULT_FILE_NAME);
+    expect(offenses).toHaveLength(1);
+  });
+
+  it('reports no error when a section only defines presets', async () => {
+    const sourceCode = `
+      {% schema %}
+      {
+        "name": "Test section",
+        "presets": [{ "name": "Preset 1" }]
+      }
+      {% endschema %}`;
+
+    const offenses = await runLiquidCheck(SchemaPresetsAndDefault, sourceCode, DEFAULT_FILE_NAME);
+    expect(offenses).toHaveLength(0);
+  });
+
+  it('reports no error when a section only defines default', async () => {
+    const sourceCode = `
+      {% schema %}
+      {
+        "name": "Test section",
+        "default": { "settings": {} }
+      }
+      {% endschema %}`;
+
+    const offenses = await runLiquidCheck(SchemaPresetsAndDefault, sourceCode, DEFAULT_FILE_NAME);
+    expect(offenses).toHaveLength(0);
+  });
+
+  it('does not run on theme blocks', async () => {
+    const sourceCode = `
+      {% schema %}
+      {
+        "name": "Test block",
+        "presets": [{ "name": "Preset 1" }]
+      }
+      {% endschema %}`;
+
+    const offenses = await runLiquidCheck(
+      SchemaPresetsAndDefault,
+      sourceCode,
+      'blocks/file.liquid',
+    );
+    expect(offenses).toHaveLength(0);
+  });
+});

packages/theme-check-common/src/checks/schema-presets-and-default/index.ts

@@ -0,0 +1,46 @@
+import { getLocEnd, getLocStart, nodeAtPath } from '../../json';
+import { getSchema, isSectionSchema } from '../../to-schema';
+import { LiquidCheckDefinition, Severity, SourceCodeType } from '../../types';
+
+export const SchemaPresetsAndDefault: LiquidCheckDefinition = {
+  meta: {
+    code: 'SchemaPresetsAndDefault',
+    name: 'Prevent sections from defining both presets and default',
+    docs: {
+      description:
+        'Reports section schemas that define both `presets` and `default`, which the platform rejects.',
+      recommended: true,
+      url: 'https://shopify.dev/docs/storefronts/themes/tools/theme-check/checks/schema-presets-and-default',
+    },
+    type: SourceCodeType.LiquidHtml,
+    severity: Severity.ERROR,
+    schema: {},
+    targets: [],
+  },
+
+  create(context) {
+    return {
+      async LiquidRawTag(node) {
+        if (node.name !== 'schema' || node.body.kind !== 'json') return;
+
+        const schema = await getSchema(context);
+        if (!isSectionSchema(schema)) return;
+
+        const { validSchema, ast } = schema;
+        if (!validSchema || validSchema instanceof Error) return;
+        if (!ast || ast instanceof Error) return;
+        if (validSchema.presets === undefined || validSchema.default === undefined) return;
+
+        const defaultNode = nodeAtPath(ast, ['default']);
+        if (!defaultNode) return;
+
+        const offset = node.blockStartPosition.end;
+        context.report({
+          message: "Invalid schema: cannot define both 'default' and 'presets'",
+          startIndex: offset + getLocStart(defaultNode),
+          endIndex: offset + getLocEnd(defaultNode),
+        });
+      },
+    };
+  },
+};

packages/theme-check-node/configs/all.yml

@@ -160,6 +160,9 @@ ReservedDocParamNames:
 SchemaOncePerFile:
   enabled: true
   severity: 0
+SchemaPresetsAndDefault:
+  enabled: true
+  severity: 0
 SchemaPresetsBlockOrder:
   enabled: true
   severity: 1

packages/theme-check-node/configs/recommended.yml

@@ -138,6 +138,9 @@ ReservedDocParamNames:
 SchemaOncePerFile:
   enabled: true
   severity: 0
+SchemaPresetsAndDefault:
+  enabled: true
+  severity: 0
 SchemaPresetsBlockOrder:
   enabled: true
   severity: 1