fix(oas3): handle unknown YAML tags

Author: kylef

packages/openapi3-parser/CHANGELOG.md

@@ -22,6 +22,9 @@
           type: object
     ```
 
+- Prevents the parser from throwing an error upon encountering an unknown or
+  invalid YAML node tag, such as `!!unknown`.
+
 ## 0.13.1 (2020-06-22)
 
 ### Bug Fixes

packages/openapi3-parser/lib/parser/parseYAML.js

@@ -90,7 +90,11 @@ function convert(node, annotations, context) {
     copySourceMap(node.start_mark, node.end_mark, warning, namespace);
     annotations.push(warning);
   } else {
-    throw new Error(`Unsupported YAML node '${node.tag}'`);
+    const error = new namespace.elements.Annotation(`YAML Syntax: Unsupported YAML node ${node.tag}`, { classes: ['error'] });
+    copySourceMap(node.start_mark, node.end_mark, error, namespace);
+    annotations.push(error);
+
+    element = new namespace.elements.Null();
   }
 
   copySourceMap(node.start_mark, node.end_mark, element, namespace);

packages/openapi3-parser/test/unit/parser/parseYAML-test.js

@@ -32,6 +32,15 @@ describe('#parseYAML', () => {
       expect(parseResult).contain.error('YAML Syntax: found character \\t that cannot start any token, while scanning for the next token').with.sourceMap([[14, 0]]);
     });
 
+    it('fails to parse YAML document with unknown tags', () => {
+      const parseResult = parseYAML('!!unknown\n', context);
+
+      expect(parseResult).to.be.instanceof(namespace.elements.ParseResult);
+      expect(parseResult.errors.length).to.equal(1);
+
+      expect(parseResult).contain.error('YAML Syntax: Unsupported YAML node tag:yaml.org,2002:unknown').with.sourceMap([[0, 9]]);
+    });
+
     it('can handle internal YAML parser error', () => {
       // Protection against YAML parser bug where source map information isn't available
       // Particular case: https://github.com/connec/yaml-js/issues/46