Enforce array schema (#151)

- Fixed a bug where a single object incorrectly passed validation
against a schema requiring an array. Updated `JSONValidation` in
`validation.ts` to treat root-level errors as document-wide issues.
- Fixed a regression where invalid YAML produced validation errors after
the root-level error change. Added a check in `doValidation` to skip
validation for unparseable input.
- Added a test in json-validation.spec.ts to verify that a schema
expecting an array correctly rejects a single object, boolean, string
and number.

Author: skrabe

.changeset/hot-maps-marry.md

@@ -0,0 +1,5 @@
+---
+"codemirror-json-schema": patch
+---
+
+Fixed validation bugs: single objects incorrectly passed array schemas, invalid YAML caused errors after root-level change(now skipped if unparseable), and added tests ensuring non-array values(object, boolean, string, number) are correctly rejected.

src/features/__tests__/__fixtures__/schemas.ts

@@ -245,3 +245,10 @@ export const wrappedTestSchemaConditionalPropertiesOnSameObject = {
   },
   required: ["original"],
 } as JSONSchema7;
+
+export const testSchemaArrayOfObjects = {
+  type: "array",
+  items: {
+    type: "object",
+  },
+} as JSONSchema7;

src/features/__tests__/json-validation.spec.ts

@@ -4,15 +4,19 @@ import type { Diagnostic } from "@codemirror/lint";
 import { describe, it, expect } from "vitest";
 import { EditorView } from "@codemirror/view";
 
-import { testSchema, testSchema2 } from "./__fixtures__/schemas";
+import {
+  testSchema,
+  testSchema2,
+  testSchemaArrayOfObjects,
+} from "./__fixtures__/schemas";
 import { JSONMode } from "../../types";
 import { getExtensions } from "./__helpers__/index";
 import { MODES } from "../../constants";
 
 const getErrors = (
   jsonString: string,
   mode: JSONMode,
-  schema?: JSONSchema7
+  schema?: JSONSchema7,
 ) => {
   const view = new EditorView({
     doc: jsonString,
@@ -30,13 +34,13 @@ const expectErrors = (
   jsonString: string,
   errors: [from: number | undefined, to: number | undefined, message: string][],
   mode: JSONMode,
-  schema?: JSONSchema7
+  schema?: JSONSchema7,
 ) => {
   const filteredErrors = getErrors(jsonString, mode, schema).map(
-    ({ renderMessage, ...error }) => error
+    ({ renderMessage, ...error }) => error,
   );
   expect(filteredErrors).toEqual(
-    errors.map(([from, to, message]) => ({ ...common, from, to, message }))
+    errors.map(([from, to, message]) => ({ ...common, from, to, message })),
   );
 };
 
@@ -145,6 +149,65 @@ describe("json-validation", () => {
       ],
       schema: testSchema2,
     },
+    {
+      name: "reject a single object when schema expects an array",
+      mode: MODES.JSON,
+      doc: '{ "name": "John" }',
+      errors: [
+        {
+          from: 0,
+          to: 0,
+          message: "Expected `array` but received `object`",
+        },
+      ],
+      schema: testSchemaArrayOfObjects,
+    },
+    {
+      name: "reject a boolean when schema expects an array",
+      mode: MODES.JSON,
+      doc: "true",
+      errors: [
+        {
+          from: 0,
+          to: 0,
+          message: "Expected `array` but received `boolean`",
+        },
+      ],
+      schema: testSchemaArrayOfObjects,
+    },
+    {
+      name: "reject a string when schema expects an array",
+      mode: MODES.JSON,
+      doc: '"example"',
+      errors: [
+        {
+          from: 0,
+          to: 0,
+          message: "Expected `array` but received `string`",
+        },
+      ],
+      schema: testSchemaArrayOfObjects,
+    },
+    {
+      name: "reject a number when schema expects an array",
+      mode: MODES.JSON,
+      doc: "123",
+      errors: [
+        {
+          from: 0,
+          to: 0,
+          message: "Expected `array` but received `number`",
+        },
+      ],
+      schema: testSchemaArrayOfObjects,
+    },
+    {
+      name: "can handle an array of objects",
+      mode: MODES.JSON,
+      doc: '[{"name": "John"}, {"name": "Jane"}]',
+      errors: [],
+      schema: testSchemaArrayOfObjects,
+    },
   ];
   it.each([
     ...jsonSuite,
@@ -360,7 +423,7 @@ oneOfEg2: 123
       doc,
       errors.map((error) => [error.from, error.to, error.message]),
       mode,
-      schema
+      schema,
     );
   });
 });

src/features/validation.ts

@@ -85,7 +85,7 @@ export class JSONValidation {
     if (error.code === "one-of-error" && errors?.length) {
       return `Expected one of ${joinWithOr(
         errors,
-        (data) => data.data.expected
+        (data) => data.data.expected,
       )}`;
     }
     if (error.code === "type-error") {
@@ -119,6 +119,8 @@ export class JSONValidation {
     if (!text?.length) return [];
 
     const json = this.parser(view.state);
+    // skip validation if parsing fails
+    if (json.data == null) return [];
 
     let errors: JsonError[] = [];
     try {
@@ -147,7 +149,8 @@ export class JSONValidation {
       const pointer = json.pointers.get(errorPath) as JSONPointerData;
       if (
         error.name === "MaxPropertiesError" ||
-        error.name === "MinPropertiesError"
+        error.name === "MinPropertiesError" ||
+        errorPath === "" // root level type errors
       ) {
         pushRoot();
       } else if (pointer) {