fix(oas3): handle missing variables in Server Object url

Author: kylef

packages/openapi3-parser/CHANGELOG.md

@@ -1,5 +1,22 @@
 # Fury OAS3 Parser Changelog
 
+## 0.12.1 (2020-04-30)
+
+### Bug Fixes
+
+- Prevent the parser from throwing an error when handling a Server Object with
+  variables when the URL does not contain any variables. For example:
+
+  ```yaml
+  openapi: 3.0.3
+  servers:
+    - url: https://example.com
+      variables:
+        version:
+          default: '1.0'
+  paths: {}
+  ```
+
 ## 0.12.0 (2020-04-29)
 
 The package has been renamed to `@apielements/openapi3-parser`.

packages/openapi3-parser/lib/parser/oas/parseServerObject.js

@@ -15,14 +15,22 @@ const parseServerVariableObject = require('./parseServerVariableObject');
 const name = 'Server Object';
 const requiredKeys = ['url'];
 
+function extractURLVariables(path) {
+  const matches = path.match(/({.*?})/gm);
+
+  if (matches) {
+    return matches.map(x => x.substring(1, x.length - 1));
+  }
+
+  return [];
+}
+
 const validateVariablesInURL = (context, object) => {
   const url = object.getValue('url');
   const variables = object.get('variables');
   const parseResult = new context.namespace.elements.ParseResult();
 
-  const urlVariables = url
-    .match(/{(.*?)}/g)
-    .map(x => x.replace(/[{}]/g, ''));
+  const urlVariables = extractURLVariables(url);
 
   // if you define a variable that is not in URL it warns (and the variable is ignored).
   variables.keys().forEach((key) => {

packages/openapi3-parser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@apielements/openapi3-parser",
-  "version": "0.12.0",
+  "version": "0.12.1",
   "description": "Open API Specification 3 API Elements Parser",
   "author": "Apiary.io <support@apiary.io>",
   "license": "MIT",

packages/openapi3-parser/test/unit/parser/oas/parseServerObject-test.js

@@ -144,6 +144,26 @@ describe('#parseServerObject', () => {
       expect(secondHrefVariable.value.default).to.equal('1.0');
     });
 
+    it('warns when variables is defined, but no variables are in the url', () => {
+      const server = new namespace.elements.Object({
+        url: 'https://example.com/',
+        variables: {
+          version: {
+            default: '1.0',
+          },
+        },
+      });
+
+      const parseResult = parse(context)(server);
+      expect(parseResult).to.contain.warning("Server variable 'version' is not present in the URL and will be ignored");
+
+      const resource = parseResult.get(0);
+      expect(resource).to.be.instanceof(namespace.elements.Resource);
+
+      expect(resource.href.toValue()).to.equal('https://example.com/');
+      expect(resource.hrefVariables.isEmpty).to.be.true;
+    });
+
     it("warns when a URL defined variable is missing from 'variables'", () => {
       const server = new namespace.elements.Object({
         url: 'https://{username}.{server}/{version}/',