fix: crash on empty yaml (#348)

* fix: crash on empty yaml

* Create giant-wolves-tie.md

Author: ota-meshi

.changeset/giant-wolves-tie.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-json-schema-validator": patch
+---
+
+fix: crash on empty yaml

src/utils/ast/yaml.ts

@@ -126,12 +126,13 @@ export function getYAMLNodeFromPath(
 ): NodeData<YAML.YAMLNode> {
   let data: NodeData<YAML.YAMLNode> = {
     key: (sourceCode) => {
+      const doc = node.body[0];
       if (node.body.length > 1) {
-        return sourceCode.getFirstToken(node.body[0]).range!;
+        return (sourceCode.getFirstToken(doc) || doc).range!;
       }
-      const dataNode = node.body[0].content;
+      const dataNode = doc.content;
       if (dataNode == null) {
-        return sourceCode.getFirstToken(node.body[0]).range!;
+        return (sourceCode.getFirstToken(doc) || doc).range!;
       }
       if (dataNode.type === "YAMLMapping" || dataNode.type === "YAMLSequence") {
         return sourceCode.getFirstToken(dataNode).range!;

tests/fixtures/rules/no-invalid/invalid/yaml-test/test-empty01-errors.json

@@ -0,0 +1,9 @@
+[
+    {
+        "message": "Root must be object.",
+        "line": 1,
+        "column": 1,
+        "endLine": 2,
+        "endColumn": 8
+    }
+]

tests/fixtures/rules/no-invalid/invalid/yaml-test/test-empty01-input.yaml

@@ -0,0 +1 @@
+# empty