Merge pull request #181 from jaishirole/main

Fix for issue#153-relative server paths in OpenAPI

Author: Phil Sturgeon

lib/index.js

@@ -97,6 +97,10 @@ SwaggerParser.prototype.parse = async function (path, api, options, callback) {
           `Swagger Parser only supports versions ${supportedVersions.join(", ")}`
         );
       }
+
+      // This is an OpenAPI v3 schema, check if the "servers" have any relative paths and
+      // fix them if the content was pulled from a web resource
+      util.fixOasRelativeServers(schema, args.path);
     }
 
     // Looks good!

lib/util.js

@@ -1,6 +1,7 @@
 "use strict";
 
 const util = require("util");
+const url = require("@apidevtools/json-schema-ref-parser/lib/util/url");
 
 exports.format = util.format;
 exports.inherits = util.inherits;
@@ -9,3 +10,68 @@ exports.inherits = util.inherits;
  * Regular Expression that matches Swagger path params.
  */
 exports.swaggerParamRegExp = /\{([^/}]+)}/g;
+
+/**
+ * List of HTTP verbs used for OperationItem as per the Swagger specification
+ */
+const operationsList = ["get", "post", "put", "delete", "patch", "options", "head", "trace"];
+
+/**
+ * This function takes in a Server object, checks if it has relative path
+ * and then fixes it as per the path url
+ *
+ * @param {object} server - The server object to be fixed
+ * @param {string} path - The path (an http/https url) from where the file was downloaded
+ * @returns {object} - The fixed server object
+ */
+function fixServers (server, path) {
+  // Server url starting with "/" tells that it is not an http(s) url
+  if (server.url && server.url.startsWith("/")) {
+    const inUrl = url.parse(path);
+    const finalUrl = inUrl.protocol + "//" + inUrl.hostname + server.url;
+    server.url = finalUrl;
+    return server;
+  }
+}
+
+/**
+ * This function helps fix the relative servers in the API definition file
+ * be at root, path or operation's level
+ */
+function fixOasRelativeServers (schema, filePath) {
+  if (schema.openapi && (filePath && (filePath.startsWith("http:") || filePath.startsWith("https:")))) {
+    /**
+     * From OpenAPI v3 spec for Server object's url property: "REQUIRED. A URL to the target host.
+     * This URL supports Server Variables and MAY be relative, to indicate that the host location is relative to the location where
+     * the OpenAPI document is being served."
+     * Further, the spec says that "servers" property can show up at root level, in 'Path Item' object or in 'Operation' object.
+     * However, interpretation of the spec says that relative paths for servers should take into account the hostname that
+     * serves the OpenAPI file.
+     */
+    if (schema.servers) {
+      schema.servers.map(server => fixServers(server, filePath)); // Root level servers array's fixup
+    }
+
+    // Path or Operation level servers array's fixup
+    Object.keys(schema.paths).forEach(path => {
+      const pathItem = schema.paths[path];
+      Object.keys(pathItem).forEach(opItem => {
+        if (opItem === "servers") {
+          // servers at pathitem level
+          pathItem[opItem].map(server => fixServers(server, filePath));
+        }
+        else if (operationsList.includes(opItem)) {
+          // servers at operation level
+          if (pathItem[opItem].servers) {
+            pathItem[opItem].servers.map(server => fixServers(server, filePath));
+          }
+        }
+      });
+    });
+  }
+  else {
+    // Do nothing and return
+  }
+}
+
+exports.fixOasRelativeServers = fixOasRelativeServers;